Summer '21

GRO CODE UPDATED
CRACKING THE
GREEN ROOF CODE
The 2021 edition of the GRO Green Roof Code of Best Practice
continues to hold true to its original values, but also includes
guidance on blue roofs, biosolar roofs and modular green
roofs. Below, the experts at GRO explain more about this
important document…
To find out more about
joining GRO email:
membership@green
rooforganisation.org
www.greenrooforganisation.org
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The latest instalment of the GRO
Code was launched on 10th June
2021. It’s the third edition and a
special anniversary edition of the GRO
Green Roof Code of Best Practice, which
was first published in 2011 by the then
newly established GRO ‘Green Roof
Organisation’.
GRO and the Code have gone from
strength to strength since its beginnings
as a voluntary organisation of a few
enthusiastic contributors under the
keen eye of former NFRC CEO Ray
Horwood, and GRO is now a Trade
Association registered with Companies
House.
The 10 year Anniversary edition of
the GRO Code continues to hold
true to the original values of making
green roof technology accessible and
guiding best practice. The original
Code was the result of an EU funded
project at the Green Roof Centre,
University of Sheffield. As a result it was
always going to be free to access and
therefore would never be a Standard.
The Green Roof Centre took advice
from livingroofs.org and all the other
GRO members to create a document
that demystified and established
performance criteria to specify, design,
install and maintain natural-based living
roofs.
The 2021 edition of the Code has
welcomed the inclusion of the
increasingly popular and rapidly
developing technology of blue roofs,
biosolar roofs and modular green roofs.
Who is the GRO
Code for?
Green roofs are not ‘rocket
science’ but they are easy
to get wrong in a surprising
number of ways! Therefore,
the language of the Code,
and the comprehensive
glossary, are intended to
make the technology of
green roofs as accessible
as possible. The guidance
held within the Code is
as applicable to an Architect planning
a 10,000m 2 accommodation block,
to a homeowner considering a 20m 2
extension or garden office.
When should you use the
GRO Code?
It is best to consult the Code at the
earliest possible stage in a design or
project plan. Green roofs may be the
last part of the external structure to be
applied, but they have an impact on the
very structure of the building and even
the foundations. The benefits of green
roofs can be found in the Code, these
highlight where costs gained for the extra
loading can be offset by water retention
and biodiversity net gain calculations.
It is also necessary to consider
ongoing green roof maintenance at
the earliest stage. A green roof is an
investment, but it will only perform
to its full potential if it is correctly
maintained. For example, a newly
installed green roof with pre-grown
flowering turf will
need watering for
the first few weeks
and after prolonged
dry spells. With this
in mind, is there a
water supply? Does
it have any pressure?
These things are
easy to change on
paper, but difficult and
potentially expensive
during construction.
Where should the GRO Code
be used?
The UK has a unique and sometimes
frustrating climate. For such a small
country it has a peculiar range of very
dry areas, very wet areas, very windy
areas and lots of areas that have a
blend of these conditions. The Code has
drawn from the vast experience of its
members to produce guidelines that will
perform well in most of the regions of
the UK. If the site you are considering
has additional special environmental
conditions, a green roof specialist should
be consulted. The Anniversary GRO
Code is free and available to everyone
in the UK and beyond, although it is not
specifically designed for climates outside
the UK and Ireland.
Further updates and extensions to the
Code will be developed by the GRO
board and membership, led by the
Technical Committee.
10 GREENSCAPE SUMMER 2021 • www.greenscapemag.co.uk