Retrofitting homes is our biggest zero-carbon challenge

Retrofitting homes is our biggest zero-carbon challenge

George Clarke looks at the challenge of making existing homes zero-carbon

There are 25 million dwellings in Britain today and in our temperate climate, all these homes need heating and hot water and they also need power to keep the lights on. To do that requires energy and, most of the time that energy comes from fossil fuels. Things are beginning to change, but UK housing has a massive dependancy on fossil fuels.

Yet we live in a country where over 2.5 million currently live in fuel poverty. So what does the future hold for those in fuel poverty and the rest of Britain when household energy bills are predicted to increase by up to 50% from April?

Britain has an ageing housing stock. In fact, it has the oldest housing stock in Europe. Our history is absolutely fascinating and our past is reflected in our architecture; our houses and buildings tell the story of our nation and millions of tourists come to the UK to admire them. 

But, the sheer number and age of our existing housing stock poses this gigantic challenge to the UK Government: If it wants to meet its target of being net-zero carbon by 2050, how can we retrofit millions of existing homes to massively reduce their CO2 emissions?

Around 80% of all the homes that exist today will still be in use in 2050. The 244,000 new homes built each year only represent 1% of our housing stock, whereas existing homes account for 99%.

Existing housing accounts for 15% of the UK’s total carbon dioxide emissions, mainly generated from domestic boilers burning gas for hot water and heating. 15% percent is around 68 million tonnes of CO2, which is 50% more than the entire agricultural sector and approximately 7.5 times more than all industrial processes and manufacturing.

At this pace, it will take us over 500 years to really become net-zero carbon!
George Clarke Architect, writer, TV presenter and Ecodan Ambassador

So, our housing stock is a gas guzzling, carbon emitting, over-heating beast of a problem.

The heat we generate escapes from the building fabric of our homes far too easily. That is a huge waste of energy and money.

Only 50% of the homes in England have cavity or solid wall insulation. That’s right, 50% of our entire housing stock has absolutely no wall insulation at all!

Only 39% of our homes have 200mm of loft insulation in their roofs! (200mm is regarded as a good amount to minimise too much heat loss through your roof).

Surprisingly, 85% of our homes have double-glazing, which is a much higher figure than you might have imagined. However, we have no idea how old and how efficient these double-glazing installations really are.

Many of our existing homes are therefore too expensive to heat and are uncomfortable to live in. 

Thankfully, some developers and social housing providers aren’t waiting until the ban on gas boilers for new build in 2025 and are installing new heat pumps into new houses now, because they know it is the right thing to do. 

Some housing associations are also being incredibly brave and are planning major retrofit programmes for their existing house stock, not because the government have told them to do it, but because they have a long-term interest in that stock and they see the long-term benefits to their tenants and to the planet, by doing the right thing. 

Housing Associations and Social Housing Providers want their tenants to be comfortable in their existing homes and they want to reduced their energy bills.

They also know that refurbishing their stock makes it last longer, look and feel better and reduces high maintenance costs that can spiral upwards from neglect.

Retrofitting a tired and cold home can have enormous health, wellbeing and psychological benefits for tenants and homeowners.

That’s how powerful a safe, secure, stable, warm, energy-efficient zero-fuel poverty home can be.

It’s life-changing, life-improving, planet-saving stuff.

And when it comes to existing homeowners, many would love to upgrade their homes to be super green and ecological, but unfortunately so many just can’t afford to do it.

The will is there to retrofit, but often the money isn’t.  

The shocking thing for me, is that even though there has been lots of reports, white papers and millions of recommendations from very, clever people, as I sit here writing this article in January 2022 in the middle of a ‘Climate Emergency’, there is NO VIABLE, SUSTAINABLE, ACHIEVABLE ECONOMIC HOME RETROFIT PLAN FOR THE UK’S EXISTING HOUSING STOCK.

I’m serious. 

There are however, practical solutions that can be implemented now.

  • We need a massive loft, solid wall and cavity wall insulation programme to insulate every single one of our existing homes in the UK to the highest standard possible.


  • We need to fit draught excluders to every single door, keyhole and letterbox in the land and minimise heat loss.
  • We need every new home in the UK to have TRIPLE glazing. Double glazing is so 80’s! When a building regulations application is made to significantly renovate or refurbish an existing dwelling then triple glazing should be compulsory as the replacement.

Let’s set a date for every single window in Britain to be triple-glazed by.

  • Legislation should make it illegal for old gas or oil-fired boiler to be replaced with a new ones. We need to phase out ALL gas and oil-fired boilers and fast. All boilers should be replacement with clean, green heats pumps and powered by affordable green electricity. 
  • We need to revolutionise the building regulations to turn our fossil-fuel dependant, existing housing stock into the greenest homes they can possible be. It would be the most radical improvements to the building regulations since they were formed.
  • Oh, and we should scrap VAT on the refurbishment of existing buildings! We currently pay ZERO VAT to build a new build home, but we pay a huge and unfair 20% VAT to refurbish an existing home.

To prove I practice what I preach I’ve made ALL of these improvements to my own 53-year old home and the difference is unbelievable.

That’s why I recommend them because I know they work. My old, cold house is now off-the-scale comfortable and ecological with amazing thermal and acoustic insulation. It was also a very satisfying day when my gas-guzzling boiler got ripped out!

It’s just a shame the UK Government taxed me 20% when I made these much needed ecological improvements

So, how much do we think it’s going to cost to fully retrofit all the existing house in Britain?

Well, there is an average figure, although I’ve no idea how this was worked out and I always worry about ‘average’ figures because they can be misleading.

However, The Climate Change Committee (who advise the Government) have estimated that it will cost an average of around £26,000 to ecologically retrofit each home in Britain.

Of course, for many, this is not a small amount of money. But, we know we need to do this, so somehow we need to make it happen.

For me, it’s quite simple. Those that can afford to upgrade their homes should be made to do it. Those who cannot afford to upgrade their homes should be supported in every way possible to help them do it.

If the Earth really is our collective home, then we need to do things very differently and very quickly to save it. We cannot afford not to RETROFIT BRITAIN.  

George Clarke is an Architect, writer, TV presenter and Ecodan Ambassador

This article is a shortened version of a much longer blog which can be read at

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