No Better Time to Eco-Renovate

Eight potential ways to maximise government handouts

Welcome news for renovators this autumn. Firstly, it’s seen the launch of the government’s Green Homes Grant, offering homeowners and landlords two thirds of the cost of an energy efficiency improvement, up to a maximum of £5,000.

Secondly, it joins the stamp duty holiday declared in August, reducing to zero the duty payable on the first £500,000 of the cost of a property, though not a buy-to-let or second home.  

So if you have found, or fancy looking for, a doer-upper for just under £500,000, you can potentially save £8,750 on your purchase costs and receive government vouchers for £5,000 towards home improvements – £13,750 in all. If you are eligible for the grant’s low-income scheme – which means receiving at least one of 16 listed benefits, including carer’s and attendance allowance – the vouchers are worth £10,000 and can cover 100 per cent of the improvement cost. 

So what are these improvements? They’re split into two categories: primary and secondary, and you’ll need to install at least one of the primaries to quality. They include insulation – including top ups to any existing – and low-carbon measures, such as fitting an air or ground source heat pump, solar thermal panels or a biomass boiler.

The value of the voucher you receive for these, however, sets the limit for any secondary measure. In other words, if you get £1,000 towards insulating your cavity walls, you can only receive up to the same amount for draught proofing, for example.

That’s one of five secondary measures. The others include replacing single-glazed windows with double or triple glazing, adding secondary glazing to single glazing, replacing single-glazed or solid external doors with energy-efficient doors, adding thermostats and insulation to a hot water tank and installing heating controls.

And more appear to be coming. At the time of writing, additions include airtightness tests, essential structural improvements and retrofit coordinator and advisor services. But it’s the latter that’s the most intriguing and, I’d argue, the most useful.

The reason is that in June the government passed legislation to reduce the UK’s total greenhouse gas emissions to ‘net zero’ by 2050 – in other words 100 per cent compared to levels in 1990. That includes housing, which currently accounts for about 30 per cent of the UK’s energy consumption and around 20 per cent of greenhouse gas emissions. 

A net zero home would mean one whose energy efficiency is such that it can produce all the renewable, emission-free energy it needs within itself – typically through photovoltaic and solar thermal panels on the roof and a heat pump drawing warmth from the air or ground. 

Given that the UK’s 29 million homes include the oldest and least energy efficient in Europe, improving them all so dramatically is hugely ambitious.

But a renovator taking that road now could reap many benefits. Not only will they enjoy a home with the same comfortable temperature throughout the year, and minimal fuel bills, but its value as an eco-home is likely to outpace its draughtier rivals as temperatures and fuel bills continue to rise. 

Tips for would-be eco-renovators… 

1. Understand your property 

Before you buy, invest in a survey by a chartered building surveyor, ideally one experienced in the type or period of your potential upgrade. That should reveal any problems from damp areas to major structural issues – and persuade you whether or not to go ahead.

2. Have detailed plans drawn up by an architect or architectural technologist

These will enable your Green Homes Grant retrofit advisor to provide a retrofit survey – typically with a list of recommendations from minimal to total retrofit, with associated costs. 

3. Consider using PHPP software

The Passivhaus Planning Package is part of the Passivhaus design and build system, which guarantees a building’s performance. It’s currently the world’s best-known method of designing and building highly energy-efficient houses, though its renovation version – known as EnerPHit – is marginally less rigorous. Your retrofit advisor, who can also be an architect or experienced Passivhaus consultant, can feed your home’s details into the package, enabling you to model numerous solutions according to the energy efficiency required and to cost.

4. Think ‘fabric first’ 

Concentrate initially on insulation and airtightness to minimise the amount of heating the house requires.

5. Don’t forget ventilation

Sealing a house tightly will create an explosion of mould from trapped moisture in winter and stifling heat in summer. EnerPHit counters this with a whole house mechanical ventilation and heat recovery system (MVHR), which uses a central fan to draw warm, moist air from kitchens and bathrooms and replace it with constant, freshly warmed air throughout the house. 

MVHR depends on a system of single ducts running from the fan to each room, taking up significant space since they can be up 200mm in diameter plus insulation. In a renovation this requires careful planning at an early stage. 

6. Choose the heating system only after you’re sure of your home’s requirement

PHPP will give you early indication of what that’s likely to be, but any renovation will reveal surprises – and possibly changes of plan – as you proceed. There are, however, eco-renovations which function perfectly well without replacement heating systems. 

7. Look at renewables last

Photovoltaic and solar thermal panels are essentially add-ons, which can be installed at a later date when your bank balance has recovered.

8. Don’t do half measures

“If you’re going to do something, do it really well,” advises Sarah Price, head of building physics and consultancy at energy consultants Enhabit. "It’s a false economy to do a little bit now because it will cost you more if you have to go back and do it again. You can do it step by step, but just plan it.”