Building performance optimization in early-stage architectural design
In today’s fast-moving market, a significant percentage of high-end architectural projects are still awarded through competitions, which are very fast paced and often followed by concept design stages that are highly accelerated.
Clients thus increasingly expect performance statements made during the competition to remain valid during later stages, instead of facing surprises such as “But the fully glazed tower is so nice, now you’re telling me it needs too much energy?”.
Fig. 01 – Building Performance Optimization Dashboard – Banque Libano-Francaise HQ (image and simulations: BuroHappold; Architecture: Kengo Kuma & Associates)
The discussion about the need for early-stage building performance optimization therefore gains another sharp edge. With key concepts defined in a few precious weeks and from then on firmly lodged in the design DNA, how can we make sure that indeed the right design genes are present to meet energy, comfort and sustainability goals?
This question becomes even more complicated when one considers how, in many (but not all) cases, international architectural competitions are run – which I (provocatively) posit is often “design first, ask hard questions later”. While to include engineering for building and environmental performance is by now ever more expected as a deliverable, it is often less clear what influence good environmental design contributions actually have on competition outcomes.
Setting aside structural, fire and MEP engineering, whose fundamental contributions are usually well understood, how do we prove a given design will be thermally and acoustically comfortable, daylit, (naturally) ventilated, indeed healthy – and how do we thus ensure that we do make a difference?
Engineers find truth in calculations, simulations, heuristics, but also propose creative concepts whose engineering will have to happen in reality once a project is won. Excellent architects ideate a space with all its sensory articulations, not just the visual, but multi-sensorial.
Fig. 02 – Design Performance Sketch Heuristics – New Development Bank Project (sketches: BuroHappold; Architecture: Mecanoo)
During the competition process, however, a certain degree of extrapolation of architectural features not yet fully vetted, and claims of qualities that are still subject to design and engineering development often have to be made to ensure a team’s voice is heard, which may make it hard for the engineering team to define what is investigated, and in what fashion. The engineering truth may also become linked to the master narrative, which is charged with strategic impetuses. Care must therefore be taken not to lose sight of more universal goals, which inevitably become important in a project upon its commission.
Hence, returning to the initial questions (“How do we embed the right sustainability genes in a given project?” and “How do we ‘prove’ conceptual environmental quality?”), the activity of unriddling these has to tread very carefully in order to arrive at legitimate answers, and to remain truthful to principal project goals- also dispelling sometimes justified criticism of e.g. “greenwashing”. It is within this charged context that very early-stage design ideation finds itself.
This essay introduces a series of case studies that will be published over the next few months, in which we show what performance domains were evaluated in designs created during major international architectural competitions, and how the above challenges were tackled in the interdisciplinary narratives.
Domains of interest and investigation scopes naturally vary from project to project, however a few truths have been shown to amalgamate around our set of questions. First again, “How to embed sustainability and building performance DNA?”
- Advocate ceaselessly for key building parameters to respect performance goals (e.g. orientation, functional zoning, facade design, etc.)
- Ensure that concepts retain the ability to change (sometimes “bad” concepts become the de-facto identity of a design. This makes downstream optimization incredibly difficult.)
- Support a holistic temporal understanding of building performance parameters (the way spaces are inhabited over time may shed a different light on designs as opposed to “frozen”concepts)
- Retain an open mind and willingness to innovate; the architecture itself can thus become a catalyst for change
- Respect, and seek synergy with, all other disciplines that influence the design totality
Fig. 03 – District-Scale Building Simulation – FOUR Frankfurt (image and simulations: BuroHappold; Architecture: UNStudio)
Once we have a tentative consensus on the above, how can we calculate, simulate and ideate the ever-changing? To ‘prove’ it works when not all is yet defined?
- Environmental concepts need to be clearly legible across architecture and engineering deliverables, akin to the way structure enables space
- Simulations may show the “final” design state, but do not necessarily have to, as long as the architecture still has the honest capacity to develop towards optima agreed by the integrated team. This shows a design’s performance potential
- Do not shy away from showing tested but not pursued options which did not work
- Focus on spatial performance representations (e.g. daylight, spatial thermal comfort and zonal energy mapping) instead of giving absolute single performance numbers. Spatial effects are prime during the early stages.
- Show relative predicted intensities of savings and improvements only, not absolutes
- Manage and allow interpretational leeway to account for said uncertainties, but make sure you know what scenarios you are accounting for (“Glare? No.. these office workers all sit with their backs turned to the windows”).
By accepting that during accelerated design processes ongoing change is inevitable, design intent fluctuates, and interpretations are subject to specific (e.g. user behavior) scenarios, we have found in past in present work that in combination with above points, we can nonetheless arrive at solutions that have inbuilt performance robustness. In the snap shots of early-stage design performance optimization work to be published over the next months, there is always a spark of this interweaving present, however isolated, integrated, tangential or essential the scope of individual assessments has been.