Winter '21

GREENSCAPE
Ensuring Best Practice for Green Roof & Solar PV Projects MAGAZINE
WINTER 2021
Green Talk: Nick Day
GRO Review of 2021
Fire Performance
News, Views and Projects
Mythbusters: Substrates
Stormwater Management
In collaboration with the Green Roof Organisation

GREENSCAPE
IN THIS ISSUE...
Matt Downs
Editorial Director
mattdowns@media-now.co.uk
07963 330774
www.greenscapemag.co.uk
As another year draws to a close, 2021 has not been without its challenges
for those operating in the construction sector. Supply chain issues including
long lead times for materials and huge price increases, alongside problems
around recruitment of skilled labour have made planning ahead for projects absolutely
crucial. And whilst the green infrastructure sector has not been immune from these
challenges, there have still been some fantastic projects carried out across the UK, and
great progress made in spelling out the benefits of utilising and adopting green roofs
and associated systems for projects within the built environment.
This point is made by GRO in the trade association’s review of 2021. GRO has had a
busy year which saw the launch of the third edition of the GRO Code of Best Practice
in June. The GRO Code is a vital tool in ensuring best practice for those involved in the
specification and installation of green roofs, and is integral to ensuring the uptake of
green roofs and ensuring installations perform and stand the test of time. And there’s
been further work going on behind the scenes at GRO with the Technical Committee
Chair Keith Hills and Vice Chair Phil Singleton establishing working groups to update fire
guidance, develop blue roof guidance with CIRIA, refine NBS guidance for Q37 clauses,
and define the hierarchy of risks and ‘design considerations’ that need to be understood
throughout the supply chain. You can read more about what GRO’s been up to in 2021
and the association’s plans for further progress in 2022 from page 10.
Elsewhere in this issue Wallbarn talks fire testing and performance for green roofs
(page 14); Simon Hedley addresses misconceptions around British Standards and green
roof substrates in this issue’s Mythbuster (page 16); and Optigrun MD Nick Day tackles
our Green Talk QA (page 24). Enjoy the issue!
CONTRIBUTORS TO THIS ISSUE...
Front cover: Optigrun and Bridgman & Bridgman were involved in
the Salthouse project which features a green roof with a 47º pitch.
Read our Q&A with Optigrun MD Nick Day from page 24.
GREENSCAPE
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Supported by:
p16
Mythbusters
Simon Hedley of
Boughton Loam
talks British
Standards.
In our latest Mythbusters, Simon
discusses the confusion that often
arises around British Standards with
regards to green roof substrates, whilst
Dr Tom Young looks at BS8616 in more
detail.
P 16
p18
Academic Corner
Dr Tom Young
of STRI Group
focuses on
stormwater
management
In his latest Academic Corner column,
Tom, who is also on the GRO Board,
looks at some of the research with
regards to the stormwater benefits of
green roof systems in urban areas.
P 18
p24
Green Talk Q&A
Nick Day, MD of
Optigrun, tackles
this issue’s key
questions!
Nick explains why legislation is crucial
if we’re going to increase the uptake
of green roofs in the UK, discusses
interesting projects he’s been involved
with and explains why he feels
specifications have to be better.
Page 24
www.greenscapemag.co.uk • GREENSCAPE WINTER 2021 3

Contents
NEWS
6 Will UK manufacturing roar
ahead in 2022? Wallbarn’s Julian
Thurbin gives his thoughts on what
to look out for in 2022
8 Green-tech announces new
Managing Director
9 Stunning, ‘undulating’ green
roof project at Leeds Skelton Lake
Motorway Services picks up another
award
GREEN ROOFS
10 The team at GRO look back on a
busy year for the trade association
and green roof sector in 2021, and
look forward to 2022!
14 Wallbarn tackle the hot topic of
green roofs and fire performance,
and offer advice and guidance on
what to look out for when specifying
and installing green roof systems
20 The team at Boughton Loam talk
soils and substrates and explain why
natural soil is best when it comes to
growing
4 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk

GREENSCAPE
SOLAR PV
28 We take a look at an interesting
project involving PV installer
Kembla and SolarEdge, where a pub
ensured long-term cost savings and
protected its aesthetics...
32 There’s lots to consider when
specifying and installing solar
PV, so Marley’s Stuart Nicholson has
outlined his top tips to get the best
savings from a solar PV system
REGULARS
16 Simon Hedley discusses the
misconceptions around British
Standards for green roof substrates
in our latest Mythbusters column
18 Dr Tom Young focuses on
stormwater management in his
latest Academic Corner column
24 Nick Day, MD of Optigrun
answers our questions in the latest
Green Talk Q&A
www.greenscapemag.co.uk • GREENSCAPE WINTER 2021 5

News
GREENSCAPE
MCS LAUNCHES BATTERY
INSTALLATION STANDARD
MCS (Microgeneration Certification
Scheme) has launched the industry’s
first standard for the installation of
battery storage systems.
The new Battery Installation Standard
(MIS 3012) outlines the requirements
for MCS certified installers who supply,
design, and install electrical energy
storage or battery systems. It covers
installations up to 50kW and Electrical
Energy Storage Systems (EESS)
classes 1 – 4.
MCS piloted the scheme at the
beginning of 2020 with volunteer
installers, in preparation for
certification bodies to begin accepting
applications for certification.
Battery storage systems come in
numerous forms, so for the purpose
of this new standard MCS has adopted
a classification system aligned with the
four EESS classes:
Class 1 – all the components in
the same enclosure, or multiple
enclosures from the same
manufacturer but with no visible direct
current (DC) cable.
Class 2 – battery modules and inverter
in separate enclosures linked by a DC
cable but both components from the
same manufacturer.
Class 3 – as class 2 but where the
battery modules and inverter are from
different manufacturers, requiring the
installer to determine compatibility.
Class 4 – all components, including
battery modules, safety devices and
inverters, could all be from different
manufacturers but are selected and
assembled by the installer to be
compatible with each other.
MCS developed MIS 3012 with input
from industry bodies, including Tesla,
Sonnen, Moixa, Powervault, AceOn
Group, Solar Energy UK, and REA.
2022: THE YEAR THAT UK MANUFACTURING ROARS AHEAD?
Julian Thurbin,
Managing Director of
Wallbarn has provided
his thoughts on what
to look out for in the
green infrastructure
sector in 2022. Julian
explained: “2022 could
be the year that UK
manufactured products
really come into their
own as a consequence
of continued disruption to international
supply chains. It is one of the few positives
to come out of a hugely challenging
period of almost two years.
Julian Thurbin, Wallbarn MD.
“Far Eastern imports are being
particularly badly affected due to the
double whammy of the Suez issue and
Covid. This huge pressure on supply
chains is showing no sign of abating,
allowing UK producers to build a stronger
presence in sectors historically dominated
by cheaper imports.
“UK produced goods offer shorter
and more assured supply lines but
manufacturers are obviously not immune
to raw material shortages and energy/
commodities’ price rises, bringing
uncertainty and difficulties to pricing and
planning – in addition to
this, instability in Eastern
Europe may drive up
energy prices and affect
the supply of natural
resources such as timber.
Projects will need to be repriced
repeatedly between
specification and product
purchase/installation to
reflect this very dynamic
situation.
“We also believe that quality control,
ethical supply demands and cost of
production of Far Eastern imports will
mean more scrutiny taking place into
provenance of supply.
“At home the focus on fire safety will
drive market development and possible
consolidation. The roofing/balcony fire
safety market continues to develop with
more products and systems entering it.
Inferior quality and service will be shown
to be unsatisfactory and a stronger
focus on testing and reliable certification
developed. For Wallbarn, independent
product testing will remain essential.”
Wallbarn discusses fire performance on
page 14. www.wallbarn.com
6 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk

Sustainable
soils, growing
media and turf
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Light in texture with good water holding
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Roof Garden Substrate
Intensive and Extensive options
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Load bearing, fertile planting medium.
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Supplier Member of:

News
NEW MD FOR GREEN-TECH
Kris Nellist has been appointed
Managing Director at Green-tech.
He took over from former owner and
Managing Director Rachel Kay on
Monday 1st November 2021.
Green-tech was founded in 1994
by Richard and Rachel Kay but was
acquired by Agri-services group Origin
Enterprises in March of this year.
As part of the acquisition agreement
Richard and Rachel will continue to
work with Green-tech on a consultancy
basis until the end of February 2022.
Kris joined Green-tech in May as
the Interim Financial Director. He
commented: “I have a wealth of
experience working across multiple
markets for organisations of all sizes
and ownership structures and was
delighted when the opportunity at
Green-tech was presented to me.
The last five months working as
the Finance Director has provided
great insight into the running of
the business and has given me
an opportunity to understand
the market, the opportunities
and challenges we face. Working
alongside Richard and Rachel, who
understandably have vast knowledge
and expertise, has proved invaluable.
I’m now looking forward to working
with a brilliant team and building
upon their success.”
www.green-tech.co.uk
L-r: Richard and Rachel Kay, Kris Nellist and Chris Clark.
MARLEY SAYS SOLAR SET TO
PLAY A KEY ROLE IN 2022
Looking back on 2021 and forward
to 2022, Paul Reed, Chief Operating
Officer at Marley, has discussed
the challenges the construction
sector faced in 2021, alongside the
opportunities for contractors and
the supply chain when it comes
solar PV in 2022. He explained:
“Following the financial uncertainty
brought about by Covid in 2020,
the construction sector has seen a
strong recovery in 2021, thanks to a
robust performance from both RMI
and housebuilding.
“However, a combination of various
challenges has inevitably also
hampered growth. From the huge
demand for building materials and
labour causing shortages throughout
the supply chain, to price increases
and transport issues from a lack of
HGV drivers.
“Looking ahead, while challenges
remain, including price increases
due to rising energy, transport and
raw materials costs, there are some
exciting opportunities for the roofing
sector in 2022. The decarbonisation
of the UK’s housing stock, in particular
the introduction of stringent new
Above: Paul Reed, Chief Operating Officer at Marley.
carbon emissions targets under the
new Part L regulations in 2022, offers
a significant opportunity for roofing
contractors to diversify and add solar
PV to their services, which in turn,
will create valuable revenue streams
too. In fact, with Solar Energy UK
predicting that the changes to Part
L could lead to a five-fold increase in
the number of new homes built with
solar technology, those contractors
who don’t offer PV installation could
face missing out on projects. Our
integrated Marley SolarTile makes it
much easier for roofing contractors
to install PV and to further support
their business we can help them with
training and MCS registration.”
www.marley.co.uk/solar-roof-tiles/
solartile
More from Marley on page 32
8 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk

GREENSCAPE
SOLAR ENERGY UK
PARTNERS WITH MCS
Solar Energy UK has announced
a new affiliate membership in
partnership with MCS, the industryled
quality assurance scheme for
renewable energy products and
installation companies.
The new membership, open
to all solar MCS installers, will
allow them to join an affiliate
membership package and become
a valued member of the UK’s trade
association for solar and storage.
As affiliate members, installers
will have access to SEUK’s regular
newsletters, monthly webinars, and
policy briefings.
With a growing membership of
over 240 leading businesses,
Solar Energy UK says it has had a
remarkably successful year, with
residential solar deployment already
higher than the whole of 2020 and
its Lighting the Way report setting
out a roadmap for tripling solar
capacity in the UK by 2030.
Chris Hewett, Solar Energy UK’s
Chief Executive, said: “Solar Energy
UK is delighted to enter into a longterm
partnership with MCS and offer
all MCS certified solar installers a
free Affiliate Membership. As solar
is the technology at the heart of
the green homes revolution, this
partnership will help installers stay
up to speed with the latest industry
developments. It will also help
us increase our internal capacity
to deliver our target of a tripling
of residential solar by 2030 by
influencing policymakers, as well
as the construction and finance
sectors.”
Ian Rippin, CEO of MCS, said:
“We see real value in the work
undertaken by trade associations
across our industry and so I’m
delighted we can extend this
membership offer to our installers at
no extra cost to them.”
ANOTHER PRESTIGIOUS AWARD FOR ABG’S ‘UNDULATING’ GREEN
ROOF PROJECT AT LEEDS SKELTON LAKE MOTORWAY SERVICES
The stunning green roof project carried out by Cawston Specialist Roofing, ABG
Geosynthetics and Geogreen Solutions at Leeds Skelton Lake Motorway Services has
triumphed in the Green Roofing category, which was sponsored by GRO, at this year’s
NFRC UK Roofing Awards.
The UK Roofing Awards win comes on the back of the project’s recent success in the
British Association of Landscape Industries (BALI) Awards, where it won Roof Garden
project with a value over £500k category.
The Leeds Skelton services sits adjacent to a 40,000m 2 area of country park, so to
ensure the development blends in to the surrounding lakeside and to minimise the
visual impact of the development, the main 5,277m 2 amenity building features an
over-arching, undulating green roof.
The project triumphed in a tough category which featured Sky Garden’s work on the
Ashraya residential project; Malone Roofing’s work on The Centre for Agricultural
Biosciences International; and BriggsAmasco’s work on the Williamsgate Water
Treatment Works.
The winners were announced at a spectacular live event on 5th November 2021 at
The Intercontinental London – The O2, sponsored by Radmat Building Products and
hosted by Tiff Needell, where over 1,000 attendees from throughout the roofing
and construction supply chain came together to celebrate the high quality of work,
individual skill and collaboration within the sector.
James Talman, Chief Executive of the NFRC, explained: “My congratulations go out to
all those who have won at this year’s UK Roofing Awards. It takes a lot to win a Roofing
Award at the best of times, but this year it has been even harder, with all the projects
entered having been completed during the pandemic. You should all be incredibly
proud.”
Find out more on the awards at www.total-contractor.co.uk
www.greenscapemag.co.uk • GREENSCAPE WINTER 2021 9

GRO 2021 REVIEW
PUSHING ON IN 2021 & BEYOND
It’s been a busy 2021 for GRO with the launch of the updated GRO Code, new
member sign-ups, and online and live events. Greenscape hears more from the team...
GRO has had an eventful and
successful second year. As
2021 has seen the gradual
unlocking following COVID restrictions
we have kept up the pace with a lot
of our ‘behind the scenes’ work on
technical guidance and policy, while
complementing our online promotion
and networking for members with some
of our first ‘in person’ events. Thanks
to all our board, committees and
members for your support and varied
contributions, and we look forward to
pushing on even further next year.
Our first AGM in March established our
healthy financial position, and having
increased our membership to 55
members during the course of the year
we have high hopes to expand further
next year. Some of our new members
have offered particularly unique ways
for the green roof industry to develop
and engage new audiences, for example
Tales from Mother Earth, Hubbub and
the Royal Botanic Gardens at Kew
Gardens where we held a green roof
engagement exhibition in May.
Much of our member promotion
had to be online for the first part of
the year, and huge thanks goes to
David Mullholland for very thorough
social media support. The launch of
our third edition of the GRO Code of
Best Practice coincided with World
Green Roof Day in June, and provided
a chance to demonstrate how our
technical outputs can benefit members
and provide online networking
opportunities.
In the second part of the year, we have
also had Dusty Gedge doing a podcast
and speaking at the RCI Show in Milton
Keynes, and Tom Young and Maggie
Fennell Wells presenting a seminar and
trade stand at The Landscape Show
at Birmingham NEC. The Futurescape
Show at the Excel Centre in London
provided a further chance to engage
with prospective members from the
landscape industry with our interactive
display and full seminar programme
offering more members a platform to
speak and connect in person, organised
by Chris Bridgman and Mark Harris.
The NFRC Roofing Awards were also
a great opportunity to meet up and
celebrate the industry successes, and
congratulations go to ABG working
Continued on page 12 >>>
GRO was represented at a number of
live events 2021. Mark Harris and Chris
Bridgman talk to visitors at the recent
Futurescape event. Overleaf: GRO at
The Landscape Show.
10 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk

STARK TO STUNNING
in hours
Versatile M-Tray modular green roof system
Flowering sedum & all-year vegetation.
Beautiful, natural habitats for urban
cityscapes.
www.wallbarn.com
0208 916 2222
Quick delivery & easy installation.
commercial public sector domestic

GRO 2021 REVIEW
>>> Continued from page 10
with Cawston Specialist Roofing for
winning the green roof category for the
Leeds Skelton Lake Motorway Services
project. Further congratulations go to
Bridgman & Bridgman Landscapes for
success in the Prolandscaper Podium
Awards.
Alongside work on the GRO Code
revisions (see GRO’s website) our
technical committee have been
looking at several important areas of
development. Our Technical committee
Chair and vice Chair Keith Hills and Phil
Singleton have set up working groups
updating fire guidance, developing
blue roof guidance with CIRIA, refining
NBS guidance for Q37 clauses, and
defining the hierarchy of risks and
‘design considerations’ that need to be
understood through the supply chain.
We invite members to participate
and apply their technical expertise to
promote the responsible growth of the
industry by engaging with these groups,
and are also looking to develop more
guidance around modular systems
with help from members. Please get
in contact with Keith Hills (technical@
greenrooforganisation.org) if you
wish to be involved in any of these
committees. Thanks also go to our
Technical Secretary Jeff Sorrill, who
alongside work with the
technical committee
plays an important
role in helping us
develop a robust
membership
application
and approval
process to
maintain the
integrity of
GRO and our
best practice
guidelines while
supporting members
to improve their work.
On the policy side we have positioned
ourselves as the point of contact for the
Ministry for Housing, Communities and
Local Government (MHCLG) as they
develop their green roof definitions for
planning guidance. This is increasingly
important as environmental and
Left: The updated GRO Code was launched in 2021. Below: GRO at Kew Gardens.
planning legislation develop, so that we
can support local planning authorities
in confidently promoting good
quality green roofs in a way that will
provide genuine benefit to their local
communities.
Dusty Gedge has also
been involved with
helping improve the
Biodiversity Metric
3.0 green roof
information for
Biodiversity Net
Gain calculations
required by the
newly passed
Environment Bill, for
example promoting the
differentiation between
wildflowers and sedums. This
policy work will be one of GRO’s priority
areas to develop next year.
As GRO looks forward to 2022 and
approaches the second AGM next
year we have also been reviewing
our application process, membership
categories, membership benefits and
information systems to ensure we
have capacity to expand and continue
to provide great benefits to our
membership. We are excited about
engaging more landscape architects,
planners and policy makers next
year, as well as developing our core
membership categories.
Contact
GRO
email: membership@
greenrooforganisation
www.greenrooforganisation.org
Tweet: @RoofGro
We plan to provide much more
educational material online for
members and non-members to help
keep spreading the GRO message and
technical advice. This will enable us to
further increase both the quality and
quantity of green roof installations
over the coming years in
a way that provides
great contacts and
opportunities for our
members.
12 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk

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GREEN ROOFS FIRE PERFORMANCE
THE HOT TOPIC OF GREEN ROOFS
AND FIRE PERFORMANCE
There’s a lot for the supply chain to get its head around when it comes to the important issue
of fire testing and product performance. Below, the team at Wallbarn discuss the key challenges
and what to look out for when specifying and installing green roof systems...
Evaluating the fire performance
of green roofs has become
increasingly important in the
post-Grenfell years as the fire safety
of buildings, their components,
assembly, construction methods and
management take centre stage.
Green roof systems can resist the
spread of flame provided they are
correctly designed, installed and
maintained. Designers, contractors
and owners have three key reference
points: Approved Document B (ADB);
DCLG document ‘Fire Performance of
Green Roofs and Walls’ and the 2021
GRO Code published by the Green Roof
Organisation.
ADB is the main authority and has been
updated twice post-Grenfell to reflect
recommendations from the Hackitt
Report. It is the basis for all fire safety
compliance and actions and details
the minimum legal requirements and
guidance on how to meet them.
The amended ADB states that a roof
system must achieve a European
classification rating of B ROOF t(4)
when tested to CEN/TS 1187:2012 Test 4
Test Methods For External Fire Exposure
To Roofs. The test must be carried
out under BS EN 13501-5:2016 Fire
classification of construction products
and building elements.
In practice, this means physical fire
tests of the whole roof system to
demonstrate B ROOF t(4) is achieved.
Self-declarations, adaptations and
interpretations are not acceptable.
Critically, BRE test reports P110472-
1001 Issue 2, P110472-1002 Issue 2 and
P110472-1003 Issue 1 can no longer
be relied on to prove compliance with
the legal requirements of Approved
Document B. Stakeholders must
demonstrate that the whole ‘as
installed’ roof system has a valid fire
certificate.
For Wallbarn, it was of obvious
importance to understand what this
meant for our modular green roof
system M-Tray. We therefore submitted
our sedum and wildflower systems
for physical fire testing by the leading
independent test authority. Both
achieved B ROOF t(4) EXAP after 60
minute physical fire tests. But this
wasn’t the end of the story.
Testing times
Approved Document B states that a
test report to BS EN 13501-5:2016 for
the exact construction is key. So if the
insulation thickness is changed, the
membrane switched or the depth/
elements of the substrate/growing
medium altered the fire certificate may
be invalid. This would mean compliance
with B ROOF t(4) requiring possibly
thousands of different physical fire tests
to take into account the many different
scenarios of a green roof build-up.
This was as much an issue for
Wallbarn as for manufacturers of more
traditional roll-out systems because
although modular solutions are supplied
with all elements of a green roof within
the factory-assembled trays, effectively
removing the element of installer error
and creating a standardised product
with no variation, there’s still the
14 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk

potential for insulation and membrane
specifications to be changed. However,
ADB offers a solution via EXAP Reports.
These reports state that the test results
for the product (tested in accordance
with CEN/TS 1187:2012 test method 4)
have an extended application (EXAP)
and can be used in a larger range of
applications. This extended application
is carried out in conformity to CEN/
TS 16459:2019 and the application
document contains extrapolation
rules relevant to the test method and
performance of the product. In short,
it enables the physical test data to be
used in more applications than just the
physical test.
Wallbarn’s M-Tray was physically fire
tested for one hour and achieved
B ROOF t(4) and the EXAP Report,
meaning its fire classification allows
its use as part of a green roof system
with a variety of membrane/insulation
build-ups so long as those products also
have B Roof t(4) EXAP. Furthermore,
there is added assurance for specifiers
and installers when using M-Tray;
Approved Document B goes on to say
that if the green roof build-up from the
deck to the finished surface includes a
minimum 80mm of growing medium
with less than 50% organic content,
specifiers can assume there will be no
spread of fire so it can be used.
Growing medium rules
However, this does mean that the
growing medium rules need strictly
adhering to. If installers – even
accidentally – lay the substrate thinner
than 80mm in a roll-out system it may
not comply. Modular systems, such as
Wallbarn’s, overcome this challenge;
its 100mm deep trays are pre-filled
to ensure a standardised depth and
the batch tested mix of substrate
is consistently applied across the
thousands of trays filled annually.
So your installation meets the legal
requirements - but have you specified
or installed something that will actually
flourish? Many substrate mixes may
comply with organics levels but can be
aggregate heavy and will not therefore
sustain sedum plants long term; the
Advice from GRO
• Substrate: to ensure there is no danger that fire can spread or penetrate the growing
medium, GRO recommends that extensive substrates should be tested in line with
BS 8616:2019 and contain no more than 20% organic content by volume (with no peat)
and comply to GRO guidelines.
• Fire breaks: to prevent the spread of fire into or from a building on to the green roof, a
fire break of 300mm width is required around all perimeters and penetrations. The fire
break should be increased to 500mm where there are openings to the building (doors,
windows, opening rooflights etc). On large roofs, a one metre wide fire break should be
installed at 40m intervals across the roof. Fire breaks must consist of 20-50mm size
rounded pebbles (fines free) to a minimum depth of 50mm placed directly onto the
drainage board, or concrete paving stones that are a minimum 40mm thick. There should
be no substrate within the fire break area. To help maintain the fire break, a retention
angle should be included between the growing medium and the pebble margin/paving.
• Maintenance: green roofs require maintenance to ensure they remain healthy and do
not represent a fire risk. Regular removal of leaves, rubbish, old flowers and seed heads
reduces the risk from dry organic matter. Fire breaks should be maintained regularly and
kept clean of encroaching vegetation.
Above: M-Tray undergoing its fire testing.
Left: M-Tray installed.
fines fall to the bottom of the system
and can form a slurry which sets
creating an impermeable layer, slowly
killing the sedum. The sight of red, dead
and feeble green roofs is distressing to
witness, destroys the benefits the green
roof was supposed to achieve and
seriously damages the reputation and
image of green roofs.
For this challenge Wallbarn applied the
thinking behind its ADB approach – that
it would gain independent verification
(rather than self-declaration) that its
substrate supported long-term plant
health. With one of the UK’s leading
institutes it conducted 12 month plant
growth trials, starting with 11 different
substrate mixes and slowly whittling the
number down to three high-performing
mixes, of which it chose the one which
provided the best growth results. This
substrate contains less than 50%
organics and complies with British
Standard BS 8616: 2019 Specification
for performance parameters and test
methods for green roof substrates, and
follows the guidance in the GRO Code
2021.
Wallbarn believes it has met and
exceeded the requirements for fire
safety with its M-Tray green roof system.
It has the independent test certificates
to prove the system meets all the
legal requirements enabling specifiers,
installers and end users to be confident
that they are getting a fully researched,
developed and tested system with a
long-standing track record.
Contact
Wallbarn
Tel: 020 8916 2222
www.wallbarn.com
Tweet: @wallbarn
www.greenscapemag.co.uk • GREENSCAPE WINTER 2021 15

GREEN ROOFS MYTHBUSTERS
MISCONCEPTIONS AROUND BRITISH
STANDARDS FOR GREEN ROOF SUBSTRATES
Simon Hedley, MD of Boughton Loam, discusses the confusion that often arises around British
Standards with regards to green roof substrates, whilst Dr Tom Young, of STRI Group, looks at
BS8616 in more detail…
“A is when
very common
misconception
BS3882 is applied to
green roof substrates,”
explained Simon Hedley,
Managing Director of
Boughton Loam. “This
standard covers natural and
manufactured topsoil that
is moved or traded, not topsoil
remaining in situ and not green roof
substrates that do not contain topsoil.
It specifies requirements both for
multipurpose topsoil, fit for the majority
of needs, and for specialist topsoil
that has low fertility or are acidic or
calcareous.
“It sets out requirements for topsoil
classification and composition, specifying
characteristics such as texture,
acidity and contaminants. It includes
information on sampling and analysis
and gives guidance on handling and site
preparation so that soil is not degraded
during excavation, delivery or placement.
“Confusion involving BS3882 is
often associated with terms such as
‘lightweight soils’ which implies that the
green roof substrate material is in fact
a topsoil.”
Dr Tom Young,
Environment Systems
Manager at STRI Group,
continued: “A new
British Standard for
green roof substrate
testing was published
in 2019 – BS 8616:2019:
Specification for
performance parameters
and test methods for
green roof substrates.
“This standard
was published to
bring together all
the relevant test
methods needed
to test green roof
substrate into one
document. This includes
physical (Saturated Hydraulic
Conductivity, bulk density, porosity)
and chemical (pH, plant available
nutrients, Electrical Conductivity)
characteristics.
“This allows test houses
to consistently use the
same test methods
when assessing green
roof substrate. This
means that test results
can then be easily and
consistently compared.
“Before BS8616 was
published, a common issue was
different test houses using different test
methods, meaning it was very hard for
producers and clients to understand
what the results actually meant.
“A common misconception with
BS8616 is that one can
‘meet’ or ‘comply’ with
BS8616. Although there
are recommended
ranges in the standard
document (as with
the latest GRO Code
2021), these are
recommendations for
what green roof substrate
Images, top to bottom: Simon Hedley; Lifting
substrate to site; Tom Young.
commonly looks like, but states very
clearly that sometimes these ranges
may be slightly different for specific
products, and it is the producers’
and specifiers’ duty to determine if
this will be suitable and safe for the
intended use. The only exception with
the standard and GRO Code are the
maximum limits for certain heavy
metals and contaminants within the
substrate.”
Providing a bonus myth-buster
regarding green roof
substrates, Simon Hedley
concluded: “Another
myth is that there
is such a thing as a
single “LIFT” bulk
bag! There are two
types of bulk bag used
to deliver green roof
substrates, either a single
trip with a safety factor of
5-1, or a multi trip bag that has a
safety factor of 6-1. The difference is
that the single “TRIP” bag must not be
used again. The single trip bag has been
lifted to fill, store and move several
times on its journey from production
to delivery. A certificate of compliance
can be requested from the bulk bag
manufacturer if required.”
Contact
Boughton Loam
www.boughton.co.uk
Contact STRI Group
www.strigroup.com
16 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk

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ACADEMIC CORNER
GREEN ROOF STORMWATER
BENEFITS
In the latest instalment of his regular column, Dr Tom Young
looks at the benefits of green roofs with regards to stormwater
management in urban areas.
One of the most celebrated
benefits of green roofs is their
ability to store stormwater. This
is very useful in urban areas where
conventional roofs are designed to
drain rapidly, releasing large amounts
of water into main drainage networks.
With increased development and the
impacts of climate change, this rapid
drainage of water can lead to localised
flooding as drainage systems become
overwhelmed. Therefore, the ability of
green roofs to hold water and reduce
runoff can be used as part of integrated
Sustainable Drainage Schemes (SuDs)
to reduce flooding risk (Getter 2006).
A huge amount of research has been
conducted in this area. This research
covers many topics, but for the
purposes of this article, we’ll just look at
stormwater volume reduction.
Stormwater reduction
A large number of studies have shown
that extensive green roofs – less than
150 mm substrate depth – can reduce
annual runoff by between 27-81 %, and
intensive – substrate depth above
150 mm – by between 65-85 %
(Mentens et al. 2005, Berndtsson 2010).
However, this only tells the story when
averaged across a whole year. It is
known that flood events are much more
likely to occur during periods of heavy/
intense or prolonged rainfall. Green
roofs are less effective when viewed in
this context, with less rainfall retained
as rainfall event intensity, which is
measured as the amount of rainfall
falling in a period of time, increases
(Berghage et al. 2009, Berndtsson 2010,
Stovin 2010). For example, Carter &
Rasmussen 2006 found that extensive
green roofs retained 88% of rainfall
for small storms (76.2 mm). However, despite this,
the peak discharge during heavy rain
events can still be reduced by up to
50% (VanWoert et al. 2005) or at least
delayed between 0.5-2 hours by green
roofs (Berndtsson 2005, Berndtsson
2010). Both of these will significantly
help reduce urban flood risk if green
roofs are deployed on scale (Carter &
Jackson 2007).
These figures are general
figures for green roofs,
but different layers of a
green roof also affect
stormwater runoff in
different ways.
Vegetation
Generally, the more
complex, diverse and
dense the vegetation layer,
the more water that will be
initially intercepted and trapped
on leaves. This can help to slow down
the movement of water to the rest
of the green roof (Nagase & Dunnett
2012). Deeper and more complex
root systems can also help bind the
substrate together, allowing it to hold
more water. However, in some studies,
vegetation has been shown to have had
a minimal impact on water flow through
a roof, and so care must be given to
attributing too much impact on water
flow dynamics by the vegetation in
some situations (Berndtsson 2010).
Left: Dr Tom Young is on the
Substrate
The type of
substrate used on
a green roof can
vary significantly.
This can cause local
differences in water
holding capacity. However, in
terms of stormwater retention, this has
not shown to be a significant factor
in green roof stormwater retention
performance (Stovin et al. 2013). More
significant is the depth of substrate,
with an increase in stormwater holding
capacity as depth increases (VanWoert
et al. 2005). More important is the
current level of moisture held within
the green roof substrate. If this is
currently ‘full’ i.e. after a previous rain
event, then water will start flowing
through the system much earlier
than if the substrate was ‘dry’. It is
18 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk

GRO Board and is Environment Systems Director at STRI Group. Above: Heavy rain events are reportedly becoming more frequent in the UK.
important to consider how quickly this
substrate water holding capacity can
be recharged between rain events,
with vegetation, climate and slope all
important factors (Getter 2006).
Drainage layer and additional
water storage layer
The effect of drainage board layers can
increase the water holding capacity of
a green roof. Generally, the deeper and
greater capacity of a drainage board,
the greater the effect on slowing
stormwater release will be (Vesuviano
& Stovin 2013). This drainage layer
can be increased to a much greater
extent (40 mm +) in order to provide
significant improvement in water
holding capacity. Known as ‘blue’ roofs,
this type of system can hold significant
volumes of water which can also be
used to irrigate the green roof, or for
use as non-potable water for a building
(Andenaes et al. 2021). These types
of systems can increase annual water
retention from 30% (green roof) to
50% (blue green roof), and peak flow
events from extreme events from 12%
(green roof) to 60% (blue-green roof)
(Busker et al. 2022). Additional ‘smart’
systems can be used in parallel to
discharge water ahead of forecasted
storm events in order to free capacity.
Using this type of system can result in
annual water retention of up to 90%
and peak flow events to 70% (Busker
et al. 2022).
Conclusions
Green roofs are fantastic green
infrastructure tools which can be
used to improve urban spaces due to
the many benefits they can provide.
Stormwater retention is one of these
tools, but must always be treated with
caution. As part of integrated site wide
SuDs schemes, green roofs have a huge
role to play in stormwater reduction.
When built in isolation, green roofs can
still reduce the impact of extreme rain
events, but probably not as efficiently
as other SuDs options. Therefore, care
must be taken to ensure all aspects
of a site’s drainage scheme are fully
integrated and calculated in order to
get maximum benefits for the site
solutions implemented.
Contact
STRI Group
Tel: 01274 565131
www.strigroup.com
E: tom.young@strigroup.com
Tweet: @striturf_tomy
@striturf
www.greenscapemag.co.uk • GREENSCAPE WINTER 2021 19

SOILS & SUBSTRATES
WHY NATURAL SOIL IS BEST
WHEN IT COMES TO GROWING
By the experts at Boughton Loam.
Natural topsoil
is a precious
commodity,
taking anywhere
between 500-1000
years to produce
every cm of soil, so
it’s something we
need to cherish.
Soil carries out a
range of functions
and services without
which human
life would not be
possible. It provides
an environment for
plants, including
food crops, to grow
in by anchoring
roots and storing
nutrients.
It filters and cleans
our water and
helps prevent natural hazards such
as flooding. It contains immense
levels of biodiversity. Finally, it is the
largest terrestrial store of carbon, and
therefore helps to regulate the climate.
There’s so much about soil that we
do not understand or comprehend so
here’s a few facts:
• Only 1% of soil micro-organisms have
been identified.
• Soils are home to over a quarter of all
living species on earth
• In an area the size of a football field,
soil organisms produce organic matter
equivalent to the weight of 25 cars
every year.
• Soil without earthworms can be 90%
less effective at soaking up water
• Earthworms can enhance
bioremediation, as they regulate the
activity and distribution of microbes in
soil.
• One gram of soil can contain around
1 million individual fungi, while some
species can reach lengths of several
hundred metres.
• Bacteria are thought to be the most
species-rich group of organisms on
Earth, and the vast majority of them live
in the soil.
• Natural Humus is not artificially
replicable.
So, why natural soil? Environmentally
it prevents these soils being underused
or worse going to landfill, they have
intrinsic qualities not replicable by
sand-based soils. Given the rate we are
losing our soils, we
should be looking to
re-purpose these as
often as possible.
So what’s the
difference?
Arguably, there’s no
difference between
a sand-based
manufactured soil
and a natural soil as
both are produced
to meet BS3882-
2015, but….
A natural soil is
just that – natural
and largely
encompasses all the
attributes previously
mentioned;
natural soil is a
vast cauldron of
biodiversity and
microbial activity which in turn gives it
far greater ‘soil health’ characteristics
than its man-made cousins.
To give context, all cars are designed
to meet a set of rules such as NCAP
– once passed and defined as a car
there is a world of difference between
a Dacia and a Rolls Royce, just as
there is a BMW and a Ford, yet all
are classified as cars and meet the
standards set by the industry. Levels
of equipment or luxury are not
defined by the standard.
Soil is no different; BS3882-2015 sets a
framework for textural characteristics
but within the standard there is a world
of difference; soil health is one of those
Continued on page 22 >>>
20 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk

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SOILS & SUBSTRATES
>>> Continued from page 20
elements not defined by the standard,
yet it is of vital importance and is in
abundance in natural soil.
So why does soil health matter?
Good soil structure is so important for
the biological activity with the larger
pores in soil improving air movement
and drainage, the smaller pores being
able to retain moisture for plants
to use. These pores or spaces also
provide habitats for life, especially soil
bacteria which in the right conditions
can grow rapidly and can have a huge
effect on the health of the soil, turning
ammonium into useable nitrates.
This complex interaction between
the physical, chemical and biological
properties of the soil has a major
influence on soil fertility and health.
To give context, a good healthy soil with
plenty of microbial activity is equivalent
to having 12 sheep per hectare living in
the soil!
So good soil biology will provide:
• Improved cycling of nutrients
• Improved resilience
to weather i.e.
drought and
intense rain
events.
• Improved plant
growth.
Ultimately “a
healthy soil does
not pollute the
environment, rather,
it contributes to mitigating
climate change by maintaining or
increasing its carbon content.”
Our soils have been rigorously
tested by NRM, a division of Cawood
Scientific Ltd, the UK’s largest
independent provider of analytical
laboratory testing services for the
land-based industries. It was not only
tested for conformity to BS3882-
2015, but also for “soil health” which
is currently missing from BS3882
testing suite. Each time it has
outperformed its sand-based cousins.
About Boughton –
‘The forefathers
of natural soil’
“The forefathers
of the proper
topsoil supply
industry are
probably Boughton
Loam for screened
natural soils” (Tim
O’Hare, Pro Landscaper -
Soil Supplement 2021)
At Boughton we are an established
company that has been supplying the
Amenity, Landscape and Construction
Industry since 1985. We pride ourselves
in the service and commitment given to
each one of our many customers over
the last 30 years of business.
We operate from a purpose-built
production facility in Kettering,
Northamptonshire, an area well known
for its excellent source of loams and
topsoil. We also recover soil from
development sites Pre-Construction
& Green Field sites in the surrounding
neighbouring counties of Leicestershire,
Bedfordshire and Hertfordshire.
Our team, with over 30 years
of experience in the landscape,
horticulture and sports turf markets,
includes MD Simon Hedley, who has a
wealth of technical in-depth product
knowledge, and more recently Jason
Lock, who has valuable experience
in specifying and delivering projects
from a design and build contracting
background. Backed by an experienced
sales team, at Boughton we are well
placed to support all your needs.
Contact
Boughton Loam
Tel: 01536 510515
www.boughton.co.uk
@BoughtonLoam
We have a variety of products
includeing a range of Natural
Topsoils, Green Roof
Substrates, Urban
Trees soils, Composts/
Turf Dressings and
rootzones all available
loose tip, bulk bag and
25kg bags.
22 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk

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GREEN TALK NICK DAY
GREEN ROOFS: AN EASY WIN
FOR GOVERNMENT
Nick Day, Managing Director of Optigrun, answers our questions...
Greenscape: What was your path
into construction and to your
current position?
Nick Day: I have been involved in
the construction industry for most of
my working life in various technical
sales and management roles. I initially
sold underground drainage systems
and then got a position with a roof
waterproofing manufacturer. I then
spent over 25 years working within
the roof waterproofing sector before
joining Optigrun nearly 10 years ago as
a Technical Sales Manager, becoming a
Director of the UK company in 2014 and
Managing Director in 2017.
Could you tell us a bit about
Optgirun, the company’s offering
and the types of projects you get
involved with...
We supply green roof system solutions
and accessories for both extensive
and intensive roofs and products for
both flat and pitched roofs. We are
involved in a wide range of projects
from large commercial and residential
developments through to green roofs
for domestic properties.
With regards to green roofing, how
is the sector performing and do
you anticipate growth in this area
considering the government’s
climate change targets?
The green roof sector is currently in
a very healthy state and definitely on
a growth trajectory. Historically, the
green roof market was very much
centred around London and the South
East with the GLA (Greater London
Authority) adopting planning measures
to encourage the wider use of green
roofs in new build construction. More
recently, other metropolitan and
local authorities around the UK have
developed their own policies and green
roofs are now being specified nationally.
With this in mind, what more
should the government be doing
to incentivise green roofs in towns
and cities throughout the UK?
The government could definitely
do more to encourage green roof
construction, but I think at least some
of the incentive has to come through
legislation. We have a German parent
company and the green roof market
there is far more advanced than it is in
the UK. Historically though, the wide
adoption of green roofs in Germany
has been through regional
government legislation
and incentives. With the
issues we face here as
elsewhere in the world
around climate change
and biodiversity loss,
green roofs would be
a relatively easy win for
the government towards
the task of creating new
biodiverse habitat as well
as helping with the task of flood
alleviation.
We seem to be experiencing
more severe weather patterns
on a more regular basis now
– is the message around the
role that green / blue roofs can
play in reducing the impact of
severe rainfall getting through to
building owners and developers?
In my opinion, we are starting to get
the message through but there is a
long way to go. There needs to be a
sea change in the way roofs on new
buildings are designed so that the
adoption of green and blue roofs
becomes a more commonplace
measure to help manage surface water
runoff. We need to make sure, however,
that a holistic approach is taken on
individual projects and that it’s not just
a “box ticking” exercise
How important is it to keep raising
the profile of green roofs, as well as
focusing on the importance of best
practice when it comes design,
specification and installation?
It’s very important and it’s something
we are doing both at individual
manufacturer / supplier level, as well
as through our industry trade body.
We established GRO (Green
Roof Organisation) as
a trade association a
couple of years ago
with this in mind. One
Left: Nick Day,
Managing Director of
Optigrun. This image:
The BFI Film Archive
Building features a 42º
pitched green roof.
24 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk

of our aims at GRO is to help promote
green roofs and their wide benefits at
all levels and, in particular, local and
national government level. Alongside
this, GRO is establishing training
programmes to upskill the industry. We
also launched our revised GRO Green
Roof Code earlier this year to provide
the necessary design guidelines for
specifiers.
Is there a danger that building
owners and other specifiers
aren’t aware of the various
options available and important
differentiations when specifying
a green roof? – Is there enough
awareness that a green roof is
not a ‘one size fits all’ solution?
There is a slightly better understanding
of green roofs than there was four or
five years ago. However, I’m afraid too
many green and blue roof specifications
we see within the industry are quite
poor and do little to convey what is
required. For this reason, many projects
are under-budgeted in terms of the roof
element, and as a result cost cutting
Above: Optigrun provides a wide range of products and systems including its biosolar roof offering.
or even omission of the green roof
altogether can sometimes occur. I would
encourage specifiers and contractors to
speak to green roof manufacturers and
suppliers, or GRO, to get the technical
support that’s available.
What are some of the more
common mistakes designers and
installers make when it comes to
green roof projects?
General lack of detail, incorrect
specification of drainage and reservoir
layers, an assumption sometimes that
site derived material can be used as
the substrate layer and inadequate
provision of water supply to irrigate the
roof during the aftercare phase.
What are some of the myths that
exist around green roofs? Is there
one that really annoys you?
That green roofs don’t need any
maintenance. For the record, all green
– and blue roofs for that matter – need
regular maintenance visits to continue
to perform successfully.
If there was one roof that you
could green anywhere in the UK,
which one would it be?
In reality, any roof that could be, but
which isn’t! I would imagine there would
have been a greater number of green
roofs on the Olympic Park in London
if it was being designed now. Although
it wasn’t designed to have one, the
London Aquatic Centre, for example,
would have looked great with a green
roof.
Can you tell us about a green
roof project you’re particularly
proud to have been involved
with...
Continued on page 26 >>>
www.greenscapemag.co.uk • GREENSCAPE WINTER 2021 25

GREEN TALK NICK DAY
>>> Continued from page 25
Whilst I’m proud of all the roofs we have
been involved with, The BFI Film Archive
Building with its 42º pitched green roof
and Bransholme Pumping Station in
Hull with the country’s first removable
green roof come to mind.
We’re hearing a lot about material
supply and pricing challenges
throughout construction – is this
the biggest challenge currently?
If so, what would your advice be
to installers?
This is a problem for everyone in
the construction industry at present.
My advice to main contractors
and installers is to plan ahead as
much as you can with your material
requirements and to no longer expect
a “just in time” supply chain. Good
forward planning will also help to
manage some of the commercial
pressures from the price volatility we
are all currently experiencing.
What other challenges do you
feel are currently impacting the
supply chain?
The effects of Brexit and the pandemic
have impacted the haulage and
distribution sector massively and
this has affected the supply chain for
construction in a big way. This has also
resulted in large increases in haulage
costs for manufacturers and suppliers
over a fairly short period of time. The
added administration and paperwork
as a consequence of Brexit has also
added cost and lead to an increase in
lead times for products being imported
from manufacturing plants in the EU.
I do believe that we may have got
used to relatively cheap transport in
the past and that we will need to learn
to live with higher costs to ensure we
have reliable and flexible transport and
distribution infrastructure in the future.
If you had one piece of advice
about working and progressing
within the construction sector,
what would it be?
Bransholme Pumping Station in
Hull features the country’s first
removable green roof
The construction industry can provide
some fantastic career opportunities
either for those people just starting
their working lives or others looking to
make a career change. That one piece
of advice would be to make sure you
take every training opportunity you
can. Being well trained and qualified in
whatever area of the industry you’re
involved with will help you to progress
and, more importantly, will give you
more job satisfaction.
What have you learned about
your role and construction in
general over the last year-anda-half
whilst operating during
the pandemic? Are there lessons
you’ll take forward with you?
A key word would be flexibility. We were
fortunate at Optigrun not to have to
furlough staff but we had to change the
way we worked very quickly to maintain
the level of service our customers
expected from us. The wellbeing and
health of my colleagues was also
paramount, and, like many companies
we have retained a so-called hybrid
working environment since the early
days of the pandemic where our team
mix working in the office and from
home.
After what’s been a particularly
challenging couple of years for
26 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk
construction, are there reasons
to be positive within the green
roof sector and construction
industry going forward?
Yes, plenty. For one thing, our industry
body GRO is now going from strength to
strength and we will be spreading the
message about green roofs to an everwider
audience. Also, the adoption of
green roofs on a wider national basis
now will present new opportunities for
everyone, as will the increasing use of
biosolar and blue roofs.
What can we expect from
Optigrun going forward? Any new
developments to look out for?
As a leading manufacturer in the green
roof industry, we are always working
on new products and systems, some
of which are too early to talk about
yet. We had a very successful launch
of our new integrated photovoltaic
panel support system for biosolar roofs
earlier this year, and are about to reveal
some new products in our blue roof
range. We will also be launching a new
training academy provision in the first
quarter of next year to encompass both
practical and technical training.
Contact
Optigrun
Tel: 0203 589 9400
www.optigruen.com
@optigrun

THE GRO GREEN ROOF CODE 1
Green Roof Code of Best Practice
incorporating Blue Roofs and
BioSolar Applications
Anniversary Edition 2021
Photo: ABG Limited
THE GREEN ROOF ORGANISATION
THE G
ROO
Green Roof
incorporatin
BioSolar Ap
Anniversary
Photo ©ABG Ltd
The Green Roof Organisation (GRO) represents companies, organisations and
people involved in, or interested in, nature-based roof solutions that help our
towns and cities mitigate and adapt to the effects of climate change whilst
making them nicer, healthier places to live.
GRO members positively contribute to the delivery of living green and blue roofs
that support nature, provide amenity, attenuate rainwater and generate solar
energy, helping ensure no roof goes unused.
Whether you are active in ecology, design, specification, installation or the
maintenance of green and blue roofs, join GRO and help make where we
live and work greener.
Further information:
E: membership@greenrooforganisation.org
COMING
SOON
THE GRO GREEN
ROOF CODE
W: www.greenrooforganisation.org :
GRO CODE
@ROOFGRO
@WGRD2021

SOLAR PV PROJECT FOCUS
“LONG-TERM COST SAVINGS WHILE ALSO
RETAINING THE AESTHETICS OF THE PUB”
PV installer Kembla worked with SolarEdge to meet the demands of a challenging, time-sensitive
project at The Waterfront Pub and Restaurant, at Barton Marina, which maximised energy
savings and Victorian charm through the installation of a 40.5kW SolarEdge PV System.
Barton Marina, linked to the
Trent and Mersey Canal
and surrounded by ninety
acres of woodland and lakes, is one
of Staffordshire’s leading tourist
destinations. Overlooking the marina
is the popular Waterfront Pub and
Restaurant. Built in 2007 using largely
reclaimed materials, The Waterfront
resembles a Victorian canal-side
warehouse, and is designed to
accommodate up to three hundred
customers for al fresco dining on
the many terraces, or in the recently
refurbished lounge and restaurant. On
the first floor a function room with
spectacular views caters for up to
two hundred people, and is in high
demand for weddings, conferences
and parties.
The Challenge
Powered 100% by electricity, The
Waterfront’s high energy usage was
exacerbated by increasing energy
prices. As a result, the owners planned
to reduce their energy bills and achieve
a greener and more sustainable site.
In spring 2021, the UK COVID lockdown
provided a window of opportunity to
carry out refurbishments, and plans
were put in place to install a roof-top
solar PV system. The owners needed
a system that would contribute the
greatest savings to their electricity
costs and remain visually pleasing to
visitors.
The Solution
Solar PV installer, Kembla, designed a
40.5kWp SolarEdge system to make the
most of the available roof space and
deliver the maximum output and energy
savings. The system comprises ninety
450W modules, upgraded to smart
modules with forty-five P950 SolarEdge
Power Optimizers, along with a
SolarEdge 33.3kW Three Phase Inverter.
Power optimisers put more power
and design flexibility on the menu
The SolarEdge solution overcomes
the challenges of maximising system
output while keeping the Victorian
design aesthetically pleasing using the
company’s unique Power Optimizers.
These are installed underneath each
pair of modules to maximise the
Continued on page 30 >>>
The DC-optimised solution offers much
greater design freedom, improving roof
space utilisation for greater energy yield.

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SOLAR PV PROJECT FOCUS
>>> Continued from page 28
performance of each module in the
system individually. This ensures
that, unlike traditional string inverter
systems, should the performance of
some modules be impaired, for example
due to shading or soiling, the rest of
the system will continue to produce the
maximum amount of energy.
The SolarEdge DC optimised solution
also enables much greater flexibility
when it comes to laying out the roof
space. In a traditional, non-optimised
solution, module placement is limited
by the need for equal string lengths,
as well as maintaining the same
azimuth and tilt of each module. In the
SolarEdge system, no such restrictions
apply, allowing the layout of the
modules to adapt optimally to the roof
shape and design to generate more
power.
Delivering green energy in time
for re-opening
With the end of lockdown in sight, the
project took Kembla less than three
weeks from order to completion –
including gaining District Network
Operator approval to enable the
system to be connected and exporting
power to the grid. The PV system
was commissioned in time for The
Waterfront to open its doors to
customers once more.
“The system is now delivering an
estimated 35.89MWh of output each
year – offsetting 10.09 tonnes of
carbon. This delivers the equivalent
of 463 trees planted each year,” said
Declan Adams, Managing Director,
Kembla Limited.
Originally, the owners had calculated a
six-year return on investment period.
Since the re-opening, this has been
reduced to five years and, based on
the performance of the system, they
have also installed additional SolarEdge
solutions on two other buildings
– the Marina Office & Café and a
maintenance building.
Full performance monitoring for
system owners and installers
A SolarEdge Energy Meter was added to
the system to provide full visibility of the
PV performance. Using the mySolarEdge
app, the site owners can track system
production in real time. They can also
view site consumption and see how
much power is being exported back
to the grid to stay in control of their
energy usage and savings.
Kembla is able to monitor the system
remotely via the SolarEdge Monitoring
Platform. With fault detection right
down to module level and with system
alerts set up, the installer can pin-point
accurately any issues and resolve them
quickly to minimize their time on site
and maximise the system uptime.
Steve Rainsford, Barton Marina’s Site
Manager, explained: “Our focus was
very much on achieving long-term
cost savings while also retaining the
aesthetics of the pub. We certainly
gave the Kembla team a challenge as,
from order to switch-on, we could only
give them a three-week window. We
are very pleased to be taking another
step forward to making the site more
sustainable with a PV system that
makes the most of our roof space and
allows us to see exactly how much
energy we are generating and using
every day, month and year.”
The safer choice for solar
For businesses in the hospitality
industry, safety is of primary
importance when choosing a PV
system. The SolarEdge solution includes
several advanced built-in safety features
such as SafeDC and arc fault detection.
SolarEdge SafeDC is designed to
automatically power down the solar
array to a touch-safe voltage of 1V
whenever the inverter or grid is shut
down, protecting the property as well as
installers, electricians, and emergency
responders. Arc fault detection and
interruption are not required by
Installation at a glance
• 45 x P950 SolarEdge Power Optimizers
• 33.3kW Three Phase Inverter with DC
safety unit, Surge Protection Device and
Rapid Shutdown Device
• Energy Meter
UK regulations, but are commonly
requested by insurance companies.
SolarEdge inverters include this
safeguard which is designed to mitigate
the effects of some arcing faults that
may pose a fire risk.
The bottom line
In pubs, hotels and restaurants, outdoor
spaces are key to the customer
experience. So when a location
demands maximum output power from
a PV system in a setting that needs to
retain the visual impact of the building’s
exterior, module placement roof space
utilisation become a priority. The
SolarEdge system maximises energy
generation throughout its lifetime for
increased savings, and with greater
flexibility in PV layout, systems can be
designed to be more in-keeping with
the style and shape of the roof.
With increasing numbers of consumers
willing to reward more sustainable
businesses, The Waterfront now offers
its guests a green energy environment.
In addition to installing the SolarEdge
system, the owners replaced all lighting
with energy efficient LEDs and adopted
a zero-waste policy. And despite
hospitality being one of the worst hit UK
sectors during the COVID pandemic, the
owners understand that cutting their
carbon emissions will also help them to
cut their operational costs and bounce
back even faster.
Contact SolarEdge:
www.solaredge.com
@SolarEdgePV
30 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk

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please contact: technical.uk.rbs@ravago.com
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SOLAR PV ADVICE
GETTING THE BEST SAVINGS
FROM A SOLAR PV SYSTEM
By Stuart Nicholson, Roof Systems Director at Marley.
The introduction of new Part L
carbon emissions targets in
June 2022 is expected to lead
to a significant increase in demand for
PV, with figures from Solar Energy UK
predicting a five-fold increase in the
number of new homes built with solar
PV technology. There are also strong
opportunities in the retrofit market, as
local authorities seek to improve the
energy efficiency of the UK’s ageing
housing stock and soaring bills are
a catalyst for homeowners installing
renewable technology to cut costs.
A well-sized solar PV system can
cover a significant proportion of a
home or building’s annual electricity
usage - up to 65-75% in many cases -
and cut carbon emissions by around
15%. However, solar systems are only
producing electricity when it is light,
so as well as customer education
about the best way to use electrical
appliances, contractors can also add
value with technological solutions that
prevent generated electricity from
being lost back into the grid.
1Batteries As solar PV systems
only generate electricity during
the daytime, incorporating battery
storage is one way to maximise
savings. This is particularly important
if occupiers are out at work all day, as
otherwise any energy they produce is
lost back into the grid. Although battery
storage has been thought of as an
expensive option, this technology is
becoming more affordable due to the
large-scale investment in UK battery
plants for electric vehicles.
With the increasing energy demands
for electric vehicles, battery storage can
also reduce the cost of home charging.
As well as storing energy from the solar
PV system, batteries can be charged
up overnight on a lower electricity
tariff and then this power can charge
electric vehicles, or any other electrical
appliance in the house, including heat
pumps.
2Power diverters If customers
don’t have the budget for a
storage battery, then a PV power
diverter is a cheaper option that can
also help increase solar savings. The
power diverter detects when the PV
32 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk

system is
generating
more
electricity
than the
occupier can
use and will
switch something
on in the house. This
could be an immersion
heater in a hot water tank for
instance. This way, rather than it being
lost into the grid, they can keep the
electricity in the house and use it to
heat up hot water to use in the evening.
3
Occupier behaviour and
solar energy monitoring As
well as technological solutions,
there are also simple behavioural
changes that can help your customers
to optimise savings from solar. This can
include setting timers while they are
out at work, so that appliances come on
in the daytime. Also, it is best to stagger
the use of high wattage appliances,
such as the washing machine and
dishwasher, to ensure they are only
using the electricity being generated,
not paying for extra from the grid.
If they
really
want to
maximise
savings,
occupiers can
check the PV
inverter to see
how much electricity
they are generating and
keep a list of the power rating
of their appliances, so they can make
informed decisions. If the PV inverter is
installed in the loft, then fitting a solar
energy monitor in a convenient location
is a good idea. Some can even be linked
to a computer or smartphone, so users
can easily see how much power they
are generating. If they have a smart
meter, they can then compare this with
how much electricity they are using at
any given time.
4
Panel efficiency and
positions As well as considering
shading factors and position of
panels, consider the efficiency of the
panels you install for customers. When
we were installing solar panels back in
2010, they were probably 200 watts
or 220 watts peak per panel. Now, for
the same size panel, we’re seeing 50%
more power out of the same area.
When choosing PV systems, remember
that Monocrystalline panels have higher
efficiencies and our new solar panels
have been designed to generate more
electricity per panel, so that 1kWp can
be fitted in just 45 minutes.
Our technical team can offer advice
on positioning and size of solar arrays,
and we also have a configurator on our
website:
(www.marley.co.uk/solarinstall). It
even calculates the kWp output, so
you can easily achieve the required
performance.
Contact Marley
www.marley.co.uk/solar
@MarleyLtd
www.greenscapemag.co.uk • GREENSCAPE WINTER 2021 33

SOLAR PV GUARANTEE
A GUARANTEE FOR SOLAR PV
Tata Steel has introduced a solar ready enhancement to its Confidex Home Guarantee.
Greenscape takes a look at how this will help deliver homes built for the future...
Given the clear push
on sustainability
and in light of the
Future Homes Standard,
Tata Steel has introduced a
‘solar ready’ enhancement
to the Confidex Home
Guarantee, helping
developers, contractors and
self-builders deliver homes
built for the future.
With the countdown to Net
Zero well underway, there
is a big emphasis on how
we can all improve our
sustainability and lessen
our carbon footprint. The
Future Homes Standard forms a key
part of this; a new set of standards
that will complement the Building
Regulations, developed to ensure
new homes are future-proofed with
low carbon heating and world-leading
energy efficiency.
Solar panels will have an important
part to play in the delivery of this
greener future, with the UK’s solar
sector expected to double by 2030.
As such, Tata Steel, the global steel
manufacturer, has taken the decision
to enhance the 25-year Confidex Home
Guarantee for the residential sector,
making it ‘solar ready’.
The Confidex Home Guarantee is valid
on standing seam residential roof and
wall systems manufactured from Tata
Steel’s Colorcoat Prisma and Colorcoat
HPS200 Ultra and available via its
four UK supply chain partners: Tata
Steel (Colorcoat Urban), Catnic (SSR2),
Euroclad (Vieo) and EQC (Seamlap/
Seamlock).
Originally launched in 2019, the
revamped Confidex Home Guarantee
offers the same renowned protection
against paint peeling on the prefinished
steel product for a period of 25
years, regardless of where the property
is located (coast or inland); in addition
to now allowing homeowners to install
Clip and Fix Solar Panels on their roofs.
Solar panels can be installed at any
point during the 25-year guarantee
period, without prior consultation from
Tata Steel.
Tata Steel’s new ‘solar ready’ Confidex
Home will help developers and
contractors in their delivery of greener
homes, with the roofs ready for future
solar panel installations. What’s more,
the Guarantee enables developers
to offer added peace of mind to
prospective home buyers, with an
additional 15 years on top of the 10-year
NHBC guarantee.
While, as a result of the Confidex Home
Guarantee being a direct agreement
with Tata Steel, homeowners can
benefit from the assurance that, in the
unlikely event of a material fault, it can
be promptly resolved and
rectified, without the need
to go via the supply chain
or their home insurance.
The Guarantee is also
transferrable in the event of
the property being sold and
is written in accordance with
consumer law.
Speaking about the
revamped Guarantee, Dr
Peter Barker, New Product
Development Manager
at Tata Steel, said: “In the
run up to 2050, the UK
is changing the way it
builds the homes of the
future. As part of the Future Homes
Standard, homes built from 2025 will
have to produce 75% to 85% less
carbon emissions, compared to homes
delivered under the current regulations,
with the installation of solar panels
becoming increasingly popular.
“As such, we took the decision to
update our renowned Confidex Home
Guarantee in line with the changing face
of the construction and housebuilding
industries to reflect the sustainable
agenda. Through the new ‘solar ready’
Confidex Home, we’re proud to be a
small part of this journey to Net Zero,
as well as being the only pre-finished
steel manufacturer to offer a standing
seam roof and wall system guarantee
agreement direct to the homeowner.”
Find out more
about the Confidex
Guarantee
www.colorcoat-online.com/
confidexhome
34 GREENSCAPE WINTER 2021 • www.greenscapemag.co.uk

Technical support
Roofing experts on-hand to offer help and advice
Assured standards
Meets all British Standards and regulations
High-quality components
Tested for maximum performance, meaning no call backs
Estimates & fixing specs on demand
We’ll help you create them on site and on the go
Comprehensive roof solution
Easy installation with tried and tested compatible components
Need a complete
roof system?
We’ve got you covered.
With all elements brought together from a single
source, you can be confident that everything
will work together perfectly – and that high
performance is all backed up with a 15-year
system guarantee. Find your peace of mind.
marley.co.uk/roofsystem

TAKE YOUR
ROOFING BUSINESS
TO THE NEXT LEVEL WITH NFRC
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profile-raising opportunities—for all roofing disciplines
NFRC sets the highest
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disciplines. But we’re much
more than the industry’s quality
assurance stamp. Membership
of the trade association offers
contractors and suppliers a
range of powerful technical
and commercial advantages.
These include a profile on our website
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business easier for clients to find. Plus
exclusive access to technical support and
updates, an exclusive health and safety
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For suppliers, key benefits include
numerous opportunities to engage with
roofing contractors all over the country.
And as the voice of the roofing sector,
NFRC makes our members’ views
heard where it matters most. We work
with government, standards bodies
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interests of the industry, and of the
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NFRC trade
membership benefits
NFRC supplier
membership benefits
Call 020 7638 7663 or visit
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UK’s premier event for
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