+IMPACT MAGAZINE ISSUE 22

THOUGHT LEADERSHIP
THOUGHT LEADERSHIP
Ballito is notorious for extreme humid summers,
temperate winters and golden coastlines. The
sun is the most powerful light source, and an
inspiration of the name “Aurum”, which means
gold and the nexus between nature and luxury. The sun
is also a source of significant heat gain which is great
for the temperate winter months but not during summer.
Nexxagen sought to capture the benefits of the natural
light for the clients’ and planet’s advantage.
Edge certification is awarded to a building if the required
minimum 20% savings in operational energy, water and
embodied energy in materials compared to the base case
model is achieved. These efficiencies translate into a simple
pass/fail system and indicate whether the building project
has demonstrated the minimum efficiency.
Each stage of the certification consists of a two-round
submission process to GBCSA. The Aurum project is at
the preliminary certification stage and has completed
round one with the EDGE auditors.
Nexxagen has inhouse EDGE experts and entered
a contract with the EDGE auditor separately for the
design audit (preliminary stage) and the site audit (post
construction). It is recommended that a potential client
uses the same EDGE auditor for both the design and site
audit; however this is not a requirement.
EDGE certification begins during the design of the
project (stage 0) and is subsequently brought to life by
the design team.
PRELIMINARY CERTIFICATION
This process must be undertaken before the building project
is complete. If the building is complete, the client should
proceed directly to the EDGE certification.
The EDGE auditor reviews the design self-assessment to
establish if the standard requirements have been correctly
interpretated by the client.
The auditor submits a written assessment to GBCSA, which
is subject to an independent quality check.
A preliminary certificate is issued by GBCSA.
POST CONSTRUCTION
A site audit is undertaken to confirm that the building project
meets the EDGE standards. The site audit must take place
within 12 months of the project’s completion date.
The benefits of owning an EDGE-certified home are
enjoying lowered utility bills as well as improved
occupant health, comfort and wellbeing.
It is vital to select a design team that
is conscious of the planet and serious
about reducing carbon emissions.
The EDGE certificate (post construction) is issued by GBCSA
on recommendation from the auditor.
Green living measures at Aurum include solar heat pumps,
external retractable façades and louvers to prevent heat
gain, low flow water fixtures and passive design.
The design team is briefed on the level of EDGE
certification aspired to, processes, requirements and
documentation required. It is vital to select a design
team that is conscious of the planet and serious about
reducing carbon emissions as it is, at times, daunting to
meet the stringent requirements required for the standard.
From this point forward, the team sets out to achieve the
highest certification within the budget constraints of a
successful project.
It is important to balance the lighting and ventilation
benefits of glazing against the impacts of heat gain on
cooling needs and/or passive heating. For example, heat
is generally transmitted in the building at a higher rate
through glass than through walls. The goal is to find the
correct balance between the transparent (glass) and the
opaque surface in the external façades helps to maximise
daylight while minimising unwanted heat transfer,
resulting in reduced energy consumption. Nexxagen has
had a design goal to maximise illumination levels without
significantly exceeding the solar heat gains in our warm
summers, as well as to make the most of passive heating
in temperate wintertime.
Windows are usually the weakest link in the building
envelope as glass has a much lower resistance to heat flow
than other building materials. Heat flows out through
a glazed window 10 times faster than it does through a
well-insulated wall. While glazed areas are desirable to
admit solar radiation in a cold winter condition during
the day, windows in warmer summer conditions can
significantly increase the building’s cooling loads. With
this consideration, Nexxagen’s design team selected the
most balanced green measures to reduce the flow of energy
between the building and surrounds.
WATER EFFICIENCY
Current technologies in the development exist to reduce
water demand as well as recycle water and harvest rainwater
for watering plants, swimming pools and other general
purposes. There is a strong nexus between water and
energy use. Energy is used to pump water, purify water to
fixtures such as taps and faucets. Energy is also used to
heat water. More heated water requires more energy. When
efficient low flow shower heads and faucets are installed,
56 POSITIVE IMPACT ISSUE 22
POSITIVE IMPACT ISSUE 22
57