Sustainable Buildings Toolkit:
Building Work and Embodied Energy


Embodied energy is the energy locked up in a building: the energy that goes into the bricks, concrete, steel and other materials of which it’s made.

With existing buildings, that energy is in the past. We need to keep re-using buildings so as not to burn more energy in replacing them. But we can’t do anything about the materials they’re made of.

However, when it comes to capital projects, extensions, refurbishment and other building works all cause emissions and environmental damage as a result of the building materials they use and the processes they’re made by. The steel frame of an extension, the replacement asphalt to go on the flat roof, the new seating, data cabling, boiler replacement and public bar all need carbon emissions to make, deliver and instal them, and all leave a mark on the planet.

It’s important to make sure the materials and products you add to your building are chosen with care, to minimise that footprint.

Embodied Energy

The damage a material or construction technique causes depends on a number of different factors:

• Resource depletion. Example: Tropical hardwoods. Plywood made of timber from virgin forests.

• Energy used in manufacture. Example: Steel and concrete manufacture consumes huge amounts of energy.

• Transport. Example: Timber products transported from Asia or South America.

• End of life: Examples: Breaking up concrete requires large amounts of energy, and the waste can’t be used again. Dismantling carefully-constructed timber or steel frames results in components which can be reused.


The best way to reduce embodied energy is to avoid building at all – or at least to be sure your work is necessary before you go ahead. It’s helpful to go through a sequence of questions to guide decision-making for building works:

Do you need it? Is an extension necessary, or can an existing space be repurposed?  However carefully designed, new building works will nearly always cause more harm than re-use. Quite often, operational change is a better answer than building.

If you need it, then can you make it from reused and recycled materials? Like everything else, construction needs to move towards a circular, not a linear economy.

If not, then can you use zero- or low-carbon materials and construction methods? That at least minimises the construction’s carbon ‘debt’.

Are you sure you want to go ahead? Building with materials and techniques that harm the plane will only feel justifiable if you are completely sure the need is evidenced, and can be satisfied in no other way.


It’s hard to avoid building works altogether – upgrading your building for sustainability will involve building works. It’s essential that your briefing to design teams (architects, engineers, etc) and project teams (project managers, cost consultants etc) makes it clear that building sustainably is at the top of your priorities. There will be cheaper, less sustainable options for some aspects of the project. Your team may feel it’s their responsibility to make you aware of them, and since money will always be tight, it will always be tempting to go for them.

Only you can make those decisions and weigh up those options. It will be your responsibility, as client, to ensure that the organisation’s sustainability priorities are not watered down.

If you’re planning layout changes or new space, then make sure you’re thinking ahead to the whole life of a building. Construction is so damaging that building to fix a short-term need may be hard to justify. Flexibility is key. Organisational needs change, so it’s important to build flexible spaces that will still be usable even if your creative vision moves on. Any construction you commit to needs to provide as much service as possible.


To ensure your building works are designed in as sustainable a way as possible, you need to choose a design team with:

• A commitment to minimising the scope of new building works.

• Expertise in sustainable design, to ensure buildings cause minimum damage both in construction and in use.

• Awareness of the need to plan for the whole life of buildings, including how they will eventually be disassembled and reused.

For any significant refurbishment, ensure your design team work to agreed embodied carbon targets such as those defined LETI ( and aligned with RIBA. And follow some of these simple rules:

  • Less is usually more (i.e. less material has more environmental benefit),
  • Specify natural materials as much as possible,
  • Select materials and equipment that have a long service life: longevity is a key sustainability principle,
  • Consider undertaking a pre-refurbishment audit to create an inventory of what materials can be salvaged or reused,
  • Maximise recycled and reused content,
  • Commission a Circular Economy assessment to help minimise material waste,
  • Design in layers to help with future “recoverability”.

Whole-life thinking is an important part of this. Since building can be such a damaging process, it’s essential to make sure that the construction you commission will last. Sustainable design will be robust, durable, repairable, loose-fit and easy to dismantle.

Finding Guidance

There is good guidance available in the following websites about running capital projects, and designing and building as sustainably as possible.

LETI ( publish an embodied carbon primer, which is a good place to start (, along with their Climate Emergency Design Guide ( LETI also offer good advice on retrofit (

The UK Green Building Council ( has, among other resources, a ‘Solutions’ page of case studies:

Design professionals have set up climate action and other groups publishing advice. The Royal Institute of British Architects have published a Sustainable Outcomes Guide ( Architects Declare ( and Engineers Declare ( have become global networks. Others include the Architects Climate Action Network:

The Arts Green Book has brought together culturalorganisations and sustainability experts to create common guidance for making culture sustainable.