+IMPACT MAGAZINE ISSUE 15

GBCSA STUDY
GBCSA STUDY
COMPOUNDING IMPACT
The study then extrapolated the findings for
development only in the urban core versus only on the
periphery for the period up to 2050, in order to calculate
a value for the difference in emissions between the
two scenarios over the time period. The cumulative
emissions gap for the period was calculated to equal
224MtCO2e. That is almost 10 times the total emissions
for Johannesburg in 2016! Kleynhans highlights that “It
is clear that decisions in development locations made
now will have a significant impact on the emissions
(and climate change) of the future, for better or worse.”
Johannesburg was chosen as the
city in which to base the research.
DOES LOCATION MATTER?
For the study, only new builds were assessed in terms
of their embodied and operational emissions. And
this was considered over a 60-year lifecycle. When
the embodied carbon was assessed, urban buildings
tended to have a lower value than their peripheral
counterparts, largely due to the usually smaller size.
Operational emissions were significantly higher than
embodied carbon in all unit types, accounting for
approximately 72% of emissions in each case when
considered across the 60-year lifespan. This highlights
Typical
spatial
map for
urban
typologies.
Typical
spatial
map for
periphery
typologies.
Considering the longevity of spatial
planning and the built environment,
it is evident that occupants can get
“locked in” to an emissions cycle
for decades to come.
the potential impact of introducing more renewable
energy resources in order to decarbonise the grid.
When occupant travel statistics were assessed,
results showed that middle income households on
the periphery accounted for three times the emissions
of the lower income households on the periphery,
despite the fact that they tended to have similar travel
distances. This is due to middle income occupants
tending to utilise private cars while lower income
individuals were dependent on the taxi network.
A similar variance between households existed
within the urban core setting, however the figures
were much lower than on the periphery. This is due
to reduced dependence on private transport, and
easier access to services within a 1km walking radius.
Statistics showed that, while the middle income units
in both cases had higher all round emissions than
the low income units, there was, in fact, a significant
difference between the core and periphery locations.
The urban core settings had a much smaller
proportion of the total being attributed to occupant
transport impact, meaning the operational carbon
of the building had the largest impact. However,
the occupant transport impact in the periphery
settings was a significant proportion of the whole.
Considering the longevity of spatial planning and
the built environment, it is evident that occupants
can get “locked in” to an emissions cycle for decades
to come, unless the right decisions are made now for
the future.
Tebogo Losaba (Unsplash)
WHAT CAN BE DONE?
The report sets out a helpful set of recommendations
for built environment professionals and other
stakeholders. The overarching requirement to make
a meaningful reduction in emissions in the city is to
reduce both operational and transport emissions. The
former can be done by working to decarbonise the
grid and optimise the energy efficiency of a building.
The latter needs to be addressed by rethinking the
spatial framework and urban planning of our cities
so at to locate developments close to amenities and
economic opportunities.
Policy makers can play a role in setting out how and
where development can take place, making it easier or
mandatory to develop higher density residential areas
as opposed to extending the urban sprawl. Property
By 2050, the cumulative emissions gap between these two scenarios
(development in the urban periphery vs the urban core) is 224MICO2e,
almost 10 times the annual total omissions of Johannesburg in 2016
(21 MtCO2e).
owners and developers should be incentivised to
upgrade and develop urban core areas rather than
expand the city limits into green field sites. This
requires the right stakeholder collaboration to address
market conditions and demands.
Ideally, government and private funding could be
more effectively utilised to introduce or upgrade
services, community facilities, transport infrastructure,
and security in localised, higher density nodes rather
than spreading resources thin on the outskirts of the
city. “Built environment professionals in South Africa
are already using their technical skills to support the
reduction of embodied, operational and transport
related emissions at different points in the decisionmaking
process of a project’s feasibility and design,”
says Smit. “We, however, need to scale up our efforts
in order to reach our net zero targets for the future.”
The evidence is clear that considering the location
of residential developments more carefully will
significantly impact our future on the planet. Our
urban design and spatial planning now will lock in
residents’ behaviours for decades to come. We need
to ensure we lock in sustainable and healthy patterns
now that will serve us all in future.
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POSITIVE IMPACT ISSUE 15
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