A Question & Answer session with our resident expert Dr Jo Atkinson

Q: Starting simply, what do we mean by ‘retrofitting’? What is the benefit?

A: Dr Jo Atkinson: Retrofitting is about upgrading existing buildings with three main, linked aims: to improve occupants’ comfort, futureproof the buildings, and reduce energy costs. We do this mainly by improving their thermal and energy efficiency. We primarily talk about retrofitting in terms of homes, but of course this applies to commercial and other buildings too.
Gas is the main energy source for providing heating and hot water in our buildings and homes, but it’s a finite fossil fuel. As we move towards fully electric buildings, we have to address our limited supply and constrained grid. And as we move to electriv vehicles then we need to retrofit homes to reduce their energy demand, to ease stress on the grid, as well as on people’s wallets.

For example, there are over 27m existing homes in the UK, and 60% of their energy is used for heating. We can make significant reductions in the main domestic source of energy demand, heating, through changes to building fabric.

Q: What does the ABC do around retrofitting?

A: It’s true that most of our work is on newbuilds – advising councils, developers and building owners on how best to combine technologies into systems that make their buildings active, net contributors to the grid.

But through our model homes, which are built to 2005, 2012 and 2025 energy efficiency standards, we can experiment on which technologies would be best fitted to older homes.

We’re working on a new retrofitting upgrade blueprint, to give contractors and  building owners the guidance they need on how to do this important work to the best possible specifications. We assess the baseline of the building, and model how we can improve it with the technologies we’ve worked on like heat pumps, solar panelling and smart systems, all of which can be added to existing buildings relatively easily.

Q: How would you go about retrofitting a standard home? What are the things a homeowner should do?

A: There is of course no standard home, but our work suggests there are some smaller things we can do for comparatively big benefits in terms of energy consumption and costs.

There are limitations on the substantial aesthetic changes that area appropriate for upgrading  the fabric of older buildings straight off the bat, so there are many buildings where we would suggest starting with electricity generating, storage and intelligent control technologies, such as solar PV and batteries. With this being said, there are many buildings where a ‘fabric-first’ approach is appropriate, for example where a heat pump is proposed. ‘Fabric-first’ maximises the performance of a building by upgrading the envelope by adding insulation to keep the heat in and the cold out.

The problem is that we as a sector don’t have the knowledge to be able to take his approach immediately en masse. But everyone should think about installing smart systems in their home in the first instance. Regardless of the type of building or its age, we can install smart control systems which better manage how energy is distributed within the building. Once you see the benefits of this, for comparatively small costs and minimal aesthetic changes, then you’ll be much more likely to take these other steps which we need.

Q: How do you weigh up the importance of retrofitting versus focusing on newbuilds?

A: This really comes in two parts. It’s vital that we upgrade all the building stock where we can, as quickly as possible. Of course, some buildings are older and more difficult than others to work on, but there are huge gains in energy efficiency to be made by focusing on the buildings from the last hundred years. These newer homes can be improved upon relatively easily, compensating for deeper issues with older ones.

That being said, there’s still not enough being done to construct newbuilds to the required standards. Only 1% of new homes are built to the standards needed for net zero. If we don’t sort out these new buildings coming onto the grid, then we risk ending up retrofitting forever. There’s no excuse for this. We know the cost of building a new home to net zero, and we know this is far outweighed by the failure to reach net zero.

So, the simple answer is retrofitting and fixing newbuilds, and doing it now. And here at the ABC, that’s exactly what we’re working on.