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by Sean Hill on May 19, 2023
I've been involved in sustainable design for most of my career, and one of the questions I get asked most often is: what does it actually mean for a practice to be committed to sustainability? Anyone can say the words. The RIBA 2030 Climate Challenge is one of the more useful frameworks for answering that question with something concrete.
Here's what it is, what it asks of practices like ours, and why we think it matters beyond the targets themselves.
What the Challenge Actually Is
RIBA launched the 2030 Climate Challenge in 2019, updated it in 2021, and it has continued to evolve since. It's a voluntary commitment for RIBA Chartered Practices, setting specific performance targets across three areas: operational energy, embodied carbon, and water use. The overarching aim is for the UK's building stock to reach net-zero carbon by 2050, and the challenge establishes interim benchmarks that work backwards from that goal.
The headline targets are a 60% reduction in operational energy demand, a 40% reduction in embodied carbon, and a 40% reduction in potable water use, measured against a 2020 baseline. There are also requirements around indoor health and wellbeing metrics, which is a welcome acknowledgement that sustainability isn't just an environmental question; it's also about the quality of the spaces people inhabit.
Participating practices are asked to submit anonymised project data, which feeds into an industry-wide picture of how the profession is actually performing against these targets. That data layer matters. It's the difference between good intentions and measurable progress.
Why Fabric Comes First
The targets are useful, but what the challenge has done most valuably for our practice is reinforce a hierarchy of priorities that we'd already arrived at through experience: fabric first, technology second.
The instinct on sustainable projects is often to reach for systems. Heat pumps, solar panels, battery storage, MVHR. These are all part of the toolkit. But they work best, and in some cases only work properly, when the building fabric is performing well beneath them.
Fabric performance means insulation levels, airtightness, thermal bridging, glazing specification, and orientation. These decisions get made early in a project, often before the client has fully engaged with sustainability as a priority, and they're largely irreversible once the building is built. A poorly performing fabric is expensive to correct and limits how effective any subsequent technology investment can be.
The Passivhaus standard, which we hold accreditation in at RISE, takes this seriously. It sets quantified targets for heat demand, airtightness, and thermal comfort, and requires you to model the building's performance before it's built rather than hoping it will perform adequately afterwards. We apply that methodology, or a version of it calibrated to the project, across our work whether or not formal certification is the goal.
Embodied Carbon: The Conversation That's Finally Happening
For a long time the sustainability conversation in architecture focused almost exclusively on operational energy, the energy used to run a building once it's occupied. That's important, but it's only part of the picture.
Embodied carbon is the carbon locked into the materials used to construct a building: the concrete, the steel, the insulation, the finishes. For a well-insulated, low-energy building, embodied carbon can represent a significant proportion of the building's total lifetime carbon impact, sometimes more than the operational emissions over the same period.
The 2030 Climate Challenge's 40% embodied carbon reduction target is pushing the profession to take this seriously. In practice it means scrutinising materials specifications, favouring low-carbon alternatives where they're available, specifying reclaimed or recycled content where quality allows, and keeping the structural strategy as material-efficient as possible.
It also makes a strong case for retrofit over demolition. The embodied carbon in an existing building is carbon already spent. Extending and improving it carries a fraction of the environmental cost of knocking it down and building new, which is a significant consideration in a city like London with a Victorian housing stock that will still be standing in 2075 if we look after it properly.
The Water Dimension
Water tends to get less attention than energy and carbon, but the challenge's 40% reduction target in potable water use is worth taking seriously, particularly as climate projections for the UK suggest more frequent drought conditions alongside increased rainfall intensity.
In practice this means rainwater harvesting where space and planning allow, greywater recycling in larger residential schemes, and water-efficient fixtures and fittings as standard. These aren't dramatic interventions. They're decisions that add modest cost at construction stage and return meaningful savings over the building's lifetime.
Retrofitting as Strategy, Not Compromise
One of the most important shifts the 2030 Climate Challenge encourages is a reframing of retrofit. Upgrading an existing building used to be seen as second-best, what you did when you couldn't build new. That framing is now almost entirely reversed.
London's Victorian terrace stock, solid walls, minimal insulation, single-glazed sash windows, solid floors, is genuinely poor performing by modern standards. But it's also improvable, and the carbon arithmetic strongly favours improving it over replacing it. EnerPHit, the Passivhaus retrofit standard, provides a rigorous framework for achieving meaningful performance improvements in existing buildings without the embodied carbon cost of new construction.
Projects like Douglas House and the Ice Cream House in Hampstead are examples of what this looks like in practice: whole-house retrofits to EnerPHit standards, with super-insulation, airtight construction, MVHR, and solar PV, resulting in homes that are substantially cheaper to run, significantly more comfortable, and considerably better for the environment than their pre-retrofit state.
The Lexi Cinema project extended these principles into a heritage building in a cultural context, demonstrating that performance-led retrofit and conservation aren't in opposition.
Data and Accountability
The requirement to submit project data to RIBA is one of the aspects of the challenge that gets least attention but matters most for the profession's credibility on sustainability.
Self-reported commitments are easy to make. Actual performance data, measured post-occupancy rather than modelled at design stage, is much harder to argue with. The challenge's data submission process is pushing practices to close the loop between design intent and built performance, and the anonymised aggregate data creates a growing evidence base for what sustainable design actually achieves in use.
At RISE we're interested in post-occupancy performance because it's the only honest way to know whether what we're designing is working. Good modelling is necessary but not sufficient. Buildings behave in ways that models sometimes don't predict, and the feedback loop between design, construction, and performance is where the profession learns.
What This Means in Practice
The 2030 Climate Challenge isn't a certificate you apply for and display. It's a set of commitments that have to be embedded in how you run projects, from the first conversation with a client through to post-occupancy review.
For us that means raising energy strategy at feasibility stage, not at technical design. It means commissioning energy modelling before the structural strategy is fixed, not after. It means specifying with embodied carbon in mind, not as an afterthought. And it means being honest with clients when their brief and their sustainability ambitions aren't yet aligned.
The clients who get the most from this approach are the ones who engage with it early. Sustainability decisions made at concept stage cost very little and achieve a great deal. The same decisions made at tender stage are expensive and often compromised. That's the clearest thing I can say about why this matters and why it has to be a first conversation, not a last one.
Looking Forward
The 2030 targets are a point on a longer journey. The challenge will continue to evolve as research develops, as material science improves, and as the gap between policy ambition and built reality either closes or widens. What won't change is the underlying logic: buildings need to perform dramatically better than they currently do, and the profession has both the responsibility and the capability to make that happen.
At RISE, sustainability has been part of how we work since we started, not something we've added in response to market pressure. The 2030 Climate Challenge gives that commitment a shared language and a set of benchmarks that we can be held to. That accountability is useful. It's also, frankly, overdue.
If you're thinking about a project and want to understand how these principles apply in practice, we're happy to talk it through.
→ Email us at architects@risedesignstudio.co.uk
→ Or call the studio on 020 3947 5886
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