This article describes strategic design decisions that architects can make during
the initial stages of a project to minimise the use of construction materials,
reduce carbon emissions and increase energy efficiency. A proposed
prototypical Bus Rapid Transit (BRT) station Switch is used as a case study. The
investigation focuses on minimising the use of construction materials through an
iterative design and assessment process.
This article extends an earlier study which analysed existing BRT stations in South
Africa by conducting comparative life-cycle analyses (LCA). The earlier study
by Hugo, Stoffberg & Barker (2012) identified a series of guidelines to inform the
design of low-carbon and embodied energy BRT stations and determined a
specific station, the MyCiti station, as the most efficient in terms of its carbon
footprint and embodied energy intensity. As a result, the MyCiti station was
identified as benchmark for future LCAs of station designs.
The Switch prototypical BRT station is purpose designed for the Tshwane1 context
and uses the identified guidelines (Hugo, Stoffberg & Barker, 2012) as well as
carbon footprint (CF) and embodied energy (EE) of construction systems and
materials as design informants generated from a study conducted by Jones
(2011b). These informed material choices, use of low-carbon structural systems
and integration of multifunctional station components.
A cradle-to-gate2 life-cycle assessment compares the CF and EE of the Switch
station and an existing South African precedent, the MyCiti station in Cape Town. The Switch station is 35% and 34% (4.08 GJ/m2 & 378.6kgCO2/m2 vs
6.28 GJ/m2 & 574.7kgCO2/m2) more efficient than the existing MyCiti station, in
terms of respective embodied energy intensity and carbon-footprint intensity.
This prototype is proposed as a benchmark for prospective life-cycle analyses
to inform the material choice and design of future BRT stations in South Africa.
Hierdie artikel bespreek strategiese besluite wat argitekte kan neem tydens
die aanvanklike ontwerpsfase van ‘n projek om die gebruik van konstruksiemateriaal
te verminder, by te dra tot die mitigasie van klimaatsverandering en
energiedoeltreffendheid te verbeter. Deur gebruik te maak van ‘n voorgestelde
‘Bus Rapid Transit’ (BRT) stasie Switch, as gevallestudie, fokus die studie op die
vermindering van konstruksie-materiaal verbruik deur iteratiewe ontwerps- en
hersieningsprosesse.
Die artikel brei uit op ‘n vorige studie waarin bestaande BRT-stasies in Suid-
Afrika geanaliseer is. Deur gebruik te maak van ‘n vergelykende lewenssiklusanalise
(LSA) het die studie deur Hugo, Stoffberg & Barker (2012) ‘n reeks riglyne
geïdentifiseer wat die ontwerp van ‘n lae koolstof en ingeslote energie BRT‑stasie
kan inlig. Verder het die studie ook ‘n spesifieke stasie, die MyCiti-stasie,
geïdentifiseer as die mees effektiewe stasie in terme van sy koolstofinhoud en
ingeslote energie intensiteit. Hierdie stasie is as normtoets vir toekomstige LSA’s
van stasie-ontwerpe geïdentifiseer.
Die Switch prototipiese stasie is spesifiek ontwerp vir die Tshwane-konteks3
en maak gebruik van spesifieke riglyne (Hugo et al., 2012) sowel as die
koolstofinhoud en ingeslote energie van konstruksie-materiaal en -sisteme as
ontwerpsinvloede. Hierdie koolstofinhoud en ingeslote energiewaardes bereken
van ‘n studie onderneem deur Jones (2011b) was die bepalende faktor vir die
materiaal keuse, gebruik van lae koolstofkonstruksiesisteme en die integrasie
van veeldoelige stasiekomponente.
Die ‘cradle-to-gate’-LSA4 vergelyk die koolstofinhoud en ingeslote energie van
die Switch-stasie met ‘n bestaande Suid-Afrikaanse stasie, naamlik die MyCitistasie
in Kaapstad. Die navorsing (Hugo et al., 2012) onthul dat die Switch-stasie
onderskeidelik ‘n 35% en 34% (4.08 GJ/m2 & 378.6 kgCO2/m2 vs. 6.28 GJ/m2 &
574.7 kgCO2/m2) laer ingeslote energie en koolstofinhoudintensiteit het as die
bestaande MyCiti-stasie.
Hierdie prototipe fokus daarop om as normtoets vir toekomstige
lewensiklusanalises, die materiaal keuse en ontwerp van daaropvolgende BRTstasies
te begelei.
