Willmott Dixon, Wates to deliver Dutch zero carbon housing retrofits in UK

40 houses in Soesterberg, Holland, are being retrofitted under the Energiesprong initiative

Willmott Dixon and Wates Living Space are two of the founding members of Energiesprong UK, a company set up to bring an innovative zero-carbon retrofit scheme from the Netherlands to the UK market.

The mass retrofit scheme hopes to turn thousands of properties into zero-energy homes by wrapping them in clip-on insulation, and adding prefabricated clip-on roof panels that incorporate solar PV units.

Other interventions could include installing heat pumps and ventilation units, with the necessary kit housed in garden sheds. 

Offsite manufacturing and high volumes should allow each property to be upgraded for around £28,000. 

David Adams, technical director for Willmott Dixon Energy Services, is excited by the scale of what is being achieved in the Netherlands. He told Construction Manager: “It’s early days but it’s an interesting concept as it’s such a radically different approach. The ambition is very large in Holland and there is a track record of this being done at scale, so the prize is very interesting.

“As a company we have used offsite construction in the past and we are pressing on with it. The technology is not radically scary. The question is can we productionise construction to drive costs out and make it financially viable.”

To bring the Dutch model to the UK, Energiesprong UK – or Energy Jump – has been founded by a group of housing associations, contractors and specialists, brought together by consultant Arno Schmickler, formerly of the National Housing Federation.

Prefabricated roof panels incorporate solar PV units

The other members of the company are housing associations Amicus Horizon, Your Homes Newcastle, Nottingham City Homes, Accord Group, Orbit Group, Thrive Homes, Affinity Sutton and Peabody; contractors Mears, Wates Living Space and Willmott Dixon; sustainable construction specialists Beattie Passive and Sustainable Group UK.

There is also support from the Energy Saving Trust, the National Housing Federation and the National Energy Foundation.

Each of the 17 founder members has contributed £5,000 towards Energiesprong UK’s operational budget, and the new company will now focus on creating a business and financial model to adapt the scheme and prove its commercial viability in the UK. 

Arno Schmickler, currently director of consultancy Urbarno, told Construction Manager: “The 17 founder members have come together and are now investigating how to transfer the Dutch approach to the UK market. It’s a different energy and construction market so there are a lot of changes, but there are no insurmountable challenges.

“This provides huge market opportunities for the whole supply chain. One great thing is that we can look at the Netherlands and see it works there, so why can’t it work here? If contractors are interested it’s only a short trip to Holland.” 

As in the Dutch model, Energiesprong UK will initially focus on social housing as social landlords are often managing large numbers of similar property types.

Schmickler explains: “We are starting to look at the UK housing stock to identify potential schemes. We will start where the Dutch started, with terraced houses, and through a process will find a suitable project. We will initially be looking at a volume deal of around 5,000 projects as the idea thrives at scale.” 

Energiesprong UK is aiming to deliver the retrofits without grant funding or public subsidy. The work will be paid for upfront by landlords, with repayments funded from the guaranteed reduction in energy costs – the contractors will be under contract to deliver homes that meet the performance specification. 

Under the arrangement, the contractors will be penalised if the home is not energy neutral due to failures in build quality, but residents will be required to pay if energy usage is high due to their own activity.

However, although the aim is for the scheme to be self-funded in the long term, for an initial 10 prototype properties to demonstrate the system the new company is seeking funding, and exploring “local, national and European” funding routes. 

David Weatherall, lead policy adviser at the Energy Savings Trust, believes that the scheme has great potential. He told Construction Manager: “Although Energiesprong is proven in the Netherlands, the UK is a different prospect. But in terms of principle there is a logic and a big advantage to doing a one-hit energy efficient retrofit of homes.”

However, he warns that we shouldn’t underestimate the challenges. “There are cost efficiency challenges, policy challenges, occupiers have to understand the concept and suppliers and installers have to be brought on board. In the past we have had issues with our retrofit industry that other more experienced countries don’t have.”