My house renovation showed me there's little reward for going green

Philip Harvey

We recently undertook a significant building project at our home. To my shame, I didn’t follow the advice I would give to my property-buying clients looking to extend their new home.

I should have started by hiring a sustainability consultant to create a thermal model of the existing house, then assess ways to make it as energy efficient as possible. Only after this should I have considered the extra space we wanted.

By using sustainable materials and energy sources, we could have enjoyed low bills for years to come and we would have been kinder to the planet.

What we actually did was get an architect to design a large and beautiful extension that we will enjoy living in and will add maximum value. Then we found builders who could build it as cost-effectively as possible. We have ended up with a better-insulated house than the 1960s, uninsulated, Crittall-windowed one we started with, but it’s nowhere near the Passivhaus-compliant home we could have achieved.

Herein lies the government’s main problem in trying to decarbonise the UK’s existing properties: when it comes to our own homes, most of us would rather spend money on what we want rather than what the planet needs.

The government only has two weapons in its armoury: legislation and subsidy. No government can afford the level of subsidy required to have a meaningful impact or the political fallout that harsh legislation would bring.

A modicum of success is being achieved in the property investment sector where legislation is possible without upsetting too many voters.

The consequence of this is that many existing commercial properties, often owned by pension funds, are tanking in value because of the costs associated with the deep retrofits required to make them compliant. Meanwhile, private residential landlords are selling their properties because retrofits are squeezing their returns.

Millions of pounds have been spent creating strategy and guidance documents along with an ever-changing array of grants, but there hasn’t been a compelling offer to the average homeowner who is currently living perfectly comfortably in their energy-inefficient home.

The Hertfordshire Climate Change and Sustainability Partnership has published a very worthy and informative pamphlet titled Retrofitting Your House for a Cosier, Greener Home. Factually it is brilliant and provides just the sort of information everyone should be aware of.

However, the section that details the works necessary for each category of the home, along with associated costs and likely savings, is hardly appealing. For a type A home (described as pre-1919 and bigger than 200 sq m) the deepest retrofit possible will bring a 93 per cent energy saving and eliminate 9.6 tonnes of carbon emissions a year. Unfortunately, it will cost £119,600 and only reduce your bills by about £1,400 a year (a return on investment of just 1.3 per cent).

It doesn’t mention that you will probably have to move out of your home, there will be additional costs such as new kitchens, bathrooms and redecoration, and that only certain elements are zero-rated for VAT.

Many quantity surveyors I’ve spoken to believe it is more cost-effective to build a new than to carry out a deep retrofit. If your house is listed or in a conservation area, you can almost certainly forget about solar panels and double or triple glazing.

Credible sources such as the estate agency JLL say your home should be worth 15 to 20 per cent more post-retrofit. But the works still cost about 20 per cent more than a standard refurbishment. And if you don’t intend to move, what does it matter?

As a side note, our property-buying business offsets carbon at about £30 a tonne (although you can find certified schemes for less). Rather than going through a painful building project to save 9.6 tonnes of carbon, I would willingly hand over £288 per year instead.

Labour’s manifesto pledged £6.6 billion for a Warm Homes Plan, which largely seems to be for insulation and boiler upgrade grants. But Labour is also in a rush to build 1.5 million homes. In both cases it needs to be careful; big businesses, and particularly housebuilders, have a habit of cutting corners.

Any architect will tell you that present building regulations, and the (mostly subcontracted) inspectors who police them, aren’t strict enough to provide the quality required to make most new homes truly sustainable.

An affordable and plentiful supply of electricity, along with improved battery storage, could remove household fossil fuel dependency. Given our planning laws, this will probably take a lot of time.

While we are waiting, we all can and should do better to adopt new technologies as they move into the mainstream and the cost of installing them falls.

Link to article - https://www.thetimes.com/life-...