RIBA Guide Outlines Radical Plan for a Sustainable Future

CC BY 2.0. A lot of those proposed buildings in London can never be built/ Lloyd Alter

"This is our last chance to avert a climate disaster. We must act now."

The Royal Institute of British Architects recently released its 2030 Climate Challenge, but also another more important and detailed document:

The RIBA Sustainable Outcomes Guide crystallises targets that need to be achieved, with an aggressive timeline to delivery by 2030 for new and refurbished buildings, and an absolute backstop of 2050 for most existing buildings. The RIBA urges all architects to embrace these and act on them. The time for greenwash and vague targets is over: with the declared climate emergency, it is the duty of all architects and the construction industry to act now and lead the transition to a sustainable future that delivers the UN Sustainable Goals.
mitigation graph

So why is 2030 such a magic number? Why has everyone said we have 12 11 now 10 years to fix things? The answer is that it's not and we don't. What we have is a carbon budget of about 420 gigatonnes of CO2, which is the maximum that can be added to the atmosphere if we are going to have any kind of chance of keeping warming below 1.5 degrees. We are now emitting 42 gigatonnes a year, so we will blow the budget in 2030 if we don't do anything.

That doesn't mean we have ten years. We have to stop emissions much faster than that, really as fast as we can. We should have started years ago; we should have gotten serious in 2018 when this was all released, and we should acknowledge that we have run out of time.

Then we have the architecture profession and its clients. Buildings take years to design and years to construct, and of course have a lifespan that goes on for years after that. Every single kilogram of CO2 that is emitted in the making of the materials for that building (the upfront carbon emissions) goes against that carbon budget, as do operating emissions and every litre of fossil fuel used to drive to that building. Forget 1.5° and 2030; we have a simple ledger, a budget. Every architect understands that. What matters is every kilogram of carbon in every building starting right now.

RIBA Trajectories

RIBA sustainable outcomes/CC BY 2.0

This is why the RIBA 2030 Challenge and the just-released Sustainable Outcomes Guide are so important. It basically calls for action right now. Their best practices trajectory calls for architects to design buildings that meet tough targets this year:

1. Reduce operational energy demand by at least 75%, before UK offsetting
2. Reduce embodied carbon by at least 50-70%, before UK offsetting
3. Reduce potable water use by at least 40%
4. Achieve all core health and wellbeing targets

Operational carbon

Forty percent of global carbon emissions come from powering our buildings and cities. The urgency of reducing these makes a Net Zero Operational Carbon Outcome a critical construction industry target, and we consider net zero operational carbon is achievable now with offsetting.

The best place to start is to go Passive First:

  • Use form, fabric and landscape to optimise ambient lighting, heating, cooling and ventilation
  • Location, orientation, massing, protection and shading
  • Windows, daylighting, ventilation, solar and acoustic control
  • Insulation, airtightness and thermal mass

RIBA then suggests getting to zero with integrated solar systems, heat pumps and storage systems. They also note that buildings should be easy to maintain (another reason I love Passive House) and easy to understand and control.

Existing buildings

RIBA recognizes that new buildings are only a small part of the total building stock.

However, new buildings only account for 1% of the total UK building stock annually, so the existing building stock will need to be improved substantially if the built environment is to achieve net zero operational carbon by 2050... We therefore support the use of the UKBC Net Zero Framework principles of maximising the energy efficiency of the existing building first (which could be at least 50% of total operational energy), and then applying renewables and offsetting schemes to achieve net zero.

RIBA also suggests that we shouldn't rush into things. "For example, the diesel car policy has created a significant health impact due to particulates and oxides of nitrogen; while insulated and airtight buildings without appropriate windows, shading, ventilation and passive cooling strategies can suffer overheating and moisture-related problems." I do not think the two are comparable; the UK Passive House industry has more than enough experience now to do renovations that don't run into these problems.

Net Zero Embodied Carbon

credit: Architype Architects/ My favourite low-carbon building

This will be the hardest change for many in the industry.

Embodied carbon emissions are generated from the processes associated with sourcing materials, fabricating them into products and systems, transporting them to site and assembling them into a building. They also include the emissions due to maintenance, repair and replacement, as well as final demolition and disposal.
Development stages

© World Green Building Council

The biggest chunk of them is what I call Upfront Carbon. The best way to avoid them, as we and the World Green Building Council have noted, is to not build at all. However, RIBA has a good list here:

1. Prioritise building re-use.
2. Carry out whole life carbon analysis of all building elements.
3. Prioritise ethical and responsible sourcing of all materials.
4. Priortise low embodied carbon and healthy materials.
5. Minimise materials with high embodied energy impacts.
6. Target zero construction waste diverted to landfill.
7. Promote use of local natural materials.
8. Consider modular off-site construction systems.
9. Detailing to be long life and robust.
10. Design building for disassembly and the circular economy.
11. Offset remaining carbon emissions through recognized scheme.

Sustainable Connectivity and Transport

Jarrett Walker Tweet

Jarrett Walker Tweet/Screen capture

I was thrilled to see that RIBA included this, as I am always saying that, basically, transportation emissions are just people driving between buildings. As Alex Steffen noted years ago, 'What We Build Dictates How We Get Around'. Steffen wrote:

We know that density reduces driving. We know that we're capable of building really dense new neighborhoods and even of using good design, infill development and infrastructure investments to transform existing medium-low density neighborhoods into walkable compact communities... It is within our power to go much farther: to build whole metropolitan regions where the vast majority of residents live in communities that eliminate the need for daily driving, and make it possible for many people to live without private cars altogether.

RIBA gets this, and part of their proposal suggests ways to achieve net zero carbon emissions for transport by 2050:

1. Create comprehensive green transport plan including digital connectivity.
2. Prioritise high quality digital connectivity to avoid need for unnecessary travel.
3. Prioritise site selection with good proximity to public transport.
4. Provide high quality pedestrian and cycle links to local amenities.
5. Provide end of journey provision for active travel runners and cyclists (showers, dry lockers, etc).
6. Provide infrastructure for electric vehicles as a priority.
7. Provide car sharing spaces.
8. Provide suitable on-site personal storage.

I would add that dedicated e-mobility lanes and charging points are needed to cope with the coming explosion in electric bikes and scooters. Also, that the only way to really make a difference is to make fossil fuel powered cars obsolete right now, through big carbon taxes. Almost every car sold today will still be on the road in 2030.

Riba sustainable outcomes

Riba sustainable outcomes/CC BY 2.0

There is much, much more, including reducing water consumption, sustainable land use, health and wellbeing, and community values. Of course, all of these are important, but right now carbon emissions are critical.

The absolutely key point of these documents is that 2030 is the imperative that we have to act not in 2030 but immediately. We have a bucket of carbon that is almost topped out and we have to stop adding to it. As Gary Clark, chair of the Sustainable Futures Group of RIBA concludes:

This is our last chance to avert a climate disaster. We must act now.