architecture in the climate crisis...
Our profession is (finally/ belatedly) beginning to address and adapt to the climate crisis and the profound changes in the way we design that it demands. We are becoming familiar with new technologies and new ways of measuring how a building performs. We are learning new ways of working and collaborating with new disciplines. More importantly, we are having to almost completely reassess how we evaluate and judge the work we and others create.
We are understanding buildings in new ways: R-values, Y-values, Airtightness, Daylight factor, Form-factor, Embodied carbon, Lifetime carbon, Thermal Bridging, Heat Transfer Coefficients. These are all terms and concepts that were unfamiliar to many of us 20 or even 10 years ago. We are having to reevaluate our expectations for what a building should do and how it performs.
We are learning the complex ways different aspects of a building’s environmental performance work together and in some instances overlap. For instance how daylight factor and solar gain work with and against each other. How there is much more to insulation performance than U-Values: R-values, Thermal resistance and Specific heat capacity can be equally important to how a material performs in different contexts. Plus how is it made and what happens to it when it needs to be thrown away (or when it burns?).
As well as learning new technical requirements and concepts, achieving net-zero demands new ways of working. For instance collaboration with other experts and consultants must be closer and start earlier in the process. The kind of top-down design familiar to many in the past is simply impossible to align with the levels of performance required to meet new standards.
As a result of all of this, we are having to completely change the way we assess and evaluate buildings and designs. We can no longer judge a project only by traditional means: reading the plan, unpicking the materials or listening to how users respond. We also need to look to the performance data: how much energy is needed to run it? what was the energy/ carbon expended to build it? Is it comfortable to be in without artificial heating/ cooling? Is it enduring and robust?
All of this is starting to manifest in the buildings that come out of these new challenges and considerations:
The huge carbon cost of concrete and steel has meant a re-evaluation of how they are deployed. Structural gymnastics and dramatic cantilevers are harder to justify. Big spans too throw up enormous jumps in embodied carbon that suggest we might need to get much more comfortable with columns in the future. Early analyses throw up surprises that challenge embedded assumptions: for instance dense reinforced concrete grids can have lower embodied carbon than comparable timber or clt frames.
The materials we specify has become a minefield we’re only just beginning to be aware of. On the face of it some materials become really difficult to justify like metal cladding and roofing. But it’s more complex: some materials (like metals) can be infinitely recycled once they reach the end of their use in a project. Others like bricks and clay tiles come with a high carbon footprint but they have a long life and need little or no maintenance. How do you balance the carbon cost of production with the potential longevity and durability of a material? A glance around our built environment shows us that some of the most enduring (and valuable) buildings were made with materials whose carbon footprint would be questionably high if built today but have been around for decades or even centuries.
Passivhaus remains the gold standard of environmental design but achieving it can often rely on lots of questionable products and techniques: tapes, foams, fillers frequently derived from fossil fuels. Mechanical ventilation is key so what if it goes wrong. We’re also becoming more aware of the impact of VOCs on internal living environments. Through our work on family homes, we’ve worked with many clients and families who have quite profound health issues connected to VOCs in the home and we’ve had to find natural solutions to creating healthy and sustainable environments for them.
We’ve understood for a while at least that more insulation is good in reducing a building’s heat loss. But the idea that the shape of a building is possibly more important is only starting to become mainstream Highly articulated shapes and facades are bad for heat loss. As a result we’re starting to see much simpler building forms with things like balconies and loggias being provided as add-ons and external elements rather than steps or recesses in the envelope. It suggests a return to more traditional ways of adding interest to buildings through added-on ornamentation and detail.
Decades of making buildings which relied on mechanical heating and cooling and where the M&E budget exceeded that of the envelope has left the profession ill- equipped and under skilled to design buildings that can create comfortable internal environments without huge energy inputs. A solar heat analysis is now a requirement for any project in the uk and it is starting to suggest new patterns. Small, shaded openings on the south facades, larger more generous ones to the north. Clearly large expanses of glazing are a thing of the past and the glass skyscraper must surely be consigned to the dustbin of history. We’re also understanding the crucial benefit of cross ventilation: particularly for flats and apartments. It’s resurrected the deck access typology for new residential developments and suggests smaller building footprints with fewer units per core.
With a bewilderingly complex and sometimes competing set of considerations, it can be helpful and reassuring to look at traditional buildings in any location. Builders would have used passive techniques and methods achieved mostly before a fossil fuel based economy. They would also have used materials that were available nearby which by their nature would have a low carbon footprint. They would have relied on techniques and solutions that would have been tested over decades and even centuries. If we combine this learnt knowledge with modern materials and ways of measuring performance, it suggests a rich resource for designing buildings that are more comfortable in their context and environment.
Re-use and adaptive reuse
We are finally becoming aware of the huge carbon impact that comes with demolishing existing buildings. Given that very often as much as 50% of the lifetime carbon emissions of a building come through its creation, we have to completely re-set the threshold at which demolition becomes acceptable or viable. We also have to learn ways of bringing existing buildings into new uses and upgrading their environmental performance. One bit of good news for the profession is that this generally requires a high level of good quality design input to make these changes.
In general, our view is that a new understanding of the impact of demolition means we don’t just need to reassess demolishing existing buildings but to also put extra efforts into making new buildings more adaptable, flexible and enduring. Ultimately this is what constitutes good design with high quality construction and materials. We should be lobbying our clients and stakeholders to invest in buildings that will last generations rather than decades.
Inevitably, a new kind of architecture is emerging. In the same way that industrialisation gave birth to modernism, the climate crisis is defining and informing architecture that looks different, performs different, and even promotes different ways of living. As it evolves, we are having to simultaneously unlearn and unhook ourselves from ideas and aesthetics that have been fundamental to what we consider to be ‘good design’ for decades. Ribbon windows, vast desert-like flat roofs, cantilevers, exposed concrete, all these tropes of modernism and more need to be let go and replaced with a new language.
What does it look like? This new architecture is more simple in form and envelope. It has smaller and more strongly defined openings within thick and solid walls. We’re starting to see a resurgence in ‘applied decoration’: albeit usually still ‘modernist’ in spirit and detail. There’s often a strong reference to local vernacular architecture including materials and details.
Re-use and retrofit also define a new aesthetic: messier, more informal, more nuanced in terms of working around existing conditions. The ‘carte blanche’ approach to urban planning and even smaller scale architectural interventions needs to be re-assessed.
We are starting to see this new architecture emerge through the work of some new and established practices: in new build public housing by Henley Halebrown & KCA, in private homes by Office for Rural Architecture & Practice Architecture and through creative reimagining of existing buildings by Lacaton & Vassal most notably.
We should be motivated and excited by this new world: a chance to define new ways of working. An opportunity to make better buildings that nurture healthy people and a healthy planet.