We need to retrofit our buildings to address the climate emergency
By: Tabitha Whiting
Tags: Construction, Building, Climate Change, Design, Environment

An average home in the UK consumes 12,000 kWh of gas and 3,100 kWh of electricity every year (Ofgem data). That represents carbon emissions of around 3,067kg every year, the equivalent of flying over 30,000km by plane.

When we think of our carbon emissions it’s usually transport or manufacturing that comes to mind. But, in fact, the energy we consume in our home accounts for 30% of our total energy use in the UK and 20% of our carbon emissions — a pretty large proportion.

But the thing is that this high home energy use is completely unnecessary.

Much of the energy we use within our homes is simply wasted. This is because our housing stock is highly inefficient. Most of this energy is used on heating our homes, but issues like draughty, single-glazed windows, ill-fitting doors, open fireplaces, lack of insulation, bad ventilation, and more, means that much of this heat energy is immediately lost through the cracks — literally.

Not only is this wasting energy, costing us more than it should in energy bills, and causing excess carbon emissions from our homes, but it’s also making us uncomfortable. In the winter we are left layering on thick jumpers to keep warm, but in the summer our houses trap heat like greenhouses. And that’s not to mention the damp and mould that many of us experience in our homes. As climate change results in more and more extreme weather events and warmer summers, this will only worsen. The NHS is already spending £1.4 billion a year treating conditions that arise from poor housing.

The solution? Retrofit.

Retrofitting is implementing measures or technologies which improve home energy efficiency. This could be about replacing your old, inefficient gas boiler with a ground source heat pump, which takes heat from the ground and uses it to keep your home cosy. It could be about swapping out all your lights for LED light bulbs. It could be installing, or improving, insulation for your home — loft, floor, or cavity wall. It could be fitting solar panels on your roof to generate your own energy from the sun, reducing your reliance on oil and gas.

The 2018 ‘Scaling Up Retrofit 2050’ report by Nottingham Trent University and IET (Institute of Engineering and Technology) concluded that we need to retrofit 26 million homes in the UK by 2050 in order to keep within the greenhouse gas emission reductions promised by the 2008 Climate Change Act (80% less than 1990 baseline).

If we want to address the climate emergency we cannot ignore the impact that our homes have. We already have the knowledge and technology we need to undertake home retrofit on a large-scale, but in the UK (and beyond) we’ve so far failed to do this.

As it stands, it’s largely up to individual homeowners to explore and pay for retrofit improvements for themselves, and it’s often just not on the radar. We think about home improvements, but usually in a piecemeal way. We get our kitchens redone because it’s become outdated — but we don’t think about how we could reduce energy consumption at the same time. We plaster over patches of damp without thinking through the root cause.

What we need is nationwide, intensive scheme backed by the government, which aims to retrofit every home in the UK to a set standard.

“A national programme for a one-off deep retrofit [of all residential property] is needed.” Professor Marjan Sarshar, Nottingham Trent University.

What about the introduction of the Green Homes Grant — is this what we need?

In July 2020 the UK Government announced that they would be launching a Green Homes Grant, a £2 billion fund offering homeowners vouchers of up to £5,000 to undertake retrofit work on their homes.

Whilst this is a good start, it’s immediately apparent that it’s not good enough. That’s because retrofitting an entire house is intensive, and so you’d expect it to be fairly costly. £5,000 won’t even scratch the surface.

What this means, is that this is just another scheme which is promoting small-scale change when it comes to energy use in our homes. With £5,000 you might be able to replace some of your windows with triple glazed, increase your wall insulation, or replace your boiler for something more efficient. The operative word here is ‘or’ — you wouldn’t be able to do all of these things with £5,000, and so we aren’t really addressing the problem at all.

To be done well, retrofit needs to be done with a whole-house approach — assessing the needs of a house as a whole to become energy efficient. If this approach is not taken you can end up with a patchwork house, with nothing working together efficiently — and so still using excess energy.

If we compare the Green Homes Grant with the New Economics Foundation’s (NEF) proposal for what a nationwide retrofit scheme should look like, the difference is clear.

NEF’s research found that a four-year, government-led programme, where 9 million UK homes would receive a full, whole-house retrofit is the way to go. This would result in a 15% reduction in our domestic energy demand, representing carbon emissions savings of approximately 19.23MtCO2/​year by 2023/​24, or 21% of 2019 emissions from the UK’s homes.

They also found this idea to be entirely feasible within the building industry which we currently have, with the added bonus of creating around 300,000 new jobs every single year over the four year period to deliver the work. Those jobs are needed now more than ever, due to the economic impact of Covid-19.

The NEF report makes it clear that, if they’re really serious about retrofit, the UK government needs to go further and create a programme such as the model NEF are proposing to really have an impact.

So why haven’t they? My assumption would be that it’s simply not going to gain votes. Retrofit is a relatively unknown term. The Grenfell disaster has also made the public incredibly wary of insulation and external cladding. Plus, whilst the impact on carbon emissions is huge, it would be fairly invisible because it would be about the fabric of our homes operating more efficiently. As Roger Kemp of Lancaster University and the Royal Academy of Engineering, put it:

“This stuff is not very sexy, and governments like big prestige projects.” — Professor Roger Kemp

So what should we do about our own homes?

Photo by Daniel von Appen on Unsplash

All hope is not lost when it comes to home energy — there are some brilliant schemes and companies out there doing great work in this space.

If you’re a homeowner in the UK and you want to see how your home measures up, here’s a couple of places to start: