Energiesprong comes to Ecobuild 2017

This session which took place at the Ecobuild Performance Lab on the 7 March 2017 was funded by the EU through Transition Zero a project within the Horizon 2020 programme.  It was chaired by Alan Yates, Executive Director of Regeneration at Accord who gave an interview to start the session and made a short presentation setting out the Energiesprong mission – Beautiful, warm, affordable homes for life – and the parameters for success.   These are:

  • Assured Quality – 30+ years energy performance warranty
  • Affordable – financeable from energy cost savings (guaranteed)
  • Non-intrusive – refurbishment within one week
  • Design – improve look and feel – desirable product


The Energiesprong approach is based on:

  • Performance-based procurement for market driven innovation and
  • Industrial approach to long-term guaranteed whole-house retrofit.


16 partners are currently delivering Energiesprong in the UK from across both the housing and construction sectors.  Further details about partners and about Energiesprong UK can be found on the website.

There then followed presentations from the Energiesprong panel.

What does the home of 2050 look like?

Jeremy Kape, Director of Property Investment, Clarion Housing Group

We know that 80% of these homes have already been built and that by 2050 most of these homes will be heated with electricity rather than gas.  But we can’t just put in electricity.  We need to look at the fabric of these homes.  The scale of what is needed is massive.  A high percentage of or existing homes are not suited to electric heating.  The problem is huge and 2050 is not that far away.

How do we do it?  External wall insulation on its own is not enough.  A whole house approach, not a piecemeal one is needed.  Even the homes built between now and 2050 may need retrofitting to bring them up to the insulation standard required.  Energiesprong offers a solution to this.

Leading the Way in the UK

Emily Braham, Head of Sustainable Energy, Nottingham City Homes

ALMO Nottingham City Homes (NCH) is leading the way with 9 pilot homes to be fitted to Energiesprong retrofit standards.  Work is due to start in the early summer of 2017 with funding from the Horizon 2020 Remourban project of around £12k per property.  The rest of the funding is coming from Nottingham City Council through the Housing Revenue Account maintenance and investment budget (funded from tenants’ rents).  The homes selected are 2 bedroom terraced homes close to Nottingham City Centre.  The properties have an under croft and garage.  Some of these have been used as rooms by residents.  Some properties, including two in the terrace being looked at for retrofit, are privately owned as a result of the right to buy.  Surveys of the floor construction are being carried out next week to establish their construction.

Meetings with the tenants have taken place to establish how much their existing energy bills are.  They range from £1700 p.a. for the end terrace to one tenant who pays only £50 p.a.!  The modelled energy consumption is £1600 p.a.  The tenants that NCH are working with are thrilled about how their homes will look after the retrofit.  Tenants have asked for the garages to be turned into rooms, but with a blank canvas, so they can choose how they want to use the space.

NCH are now in a competitive dialogue with 3 bidders who submitted responses to an invitation to tender which was published in January 2017.  The budget these bidders have been asked to work to is £65k per property for a whole house retrofit using an Energiesprong solution.  Each of these bidders has been given a budget of £10k to come up with their answer, in dialogue with NCH.

Work is still being done on the Energy Services Plan (ESP) – how to set it up in a way that reduces the bills to £50 a month; £25 of this will be to cover the cost of the energy provided and £25 will go toward the cost of the retrofits.  This compares well with what the tenants are already paying, with only one tenant currently paying less at £45 a month.  This tenant is willing to accept the small increase proposed in exchange for the benefit of a warm and comfortable home.

NCH does face some challenges.  In the Netherlands the contractor is responsible for any ongoing maintenance required.  This model does not work for NCH as we have in house contractors who take responsibility for this.  Energiesprong is based around a 30 year guarantee.  We have been engaging with our legal team to ensure that this can work.

Another challenge can be procurement.  A good procurement officer, who is able to offer innovative solutions, is key to the success of this type of project. It is worth engaging with them as soon as you can.

Leading the Way – the Dutch example

Ron van Erck, Head of International Market Development, Stroomversnelling

What we have understood in the Netherlands is that many millions of existing homes are not fit for purpose; what is happening now is not enough in terms of scale and when homes are retrofitted there is often a performance gap meaning those homes are still not as energy efficient as they should be.

Residents are not excited about insulation and they don’t want builders in for 3 months.  We need to offer a desirable solution which is quick to install.  Energiesprong offers all of this.

In the Netherlands 111,000 homes are due to be improved using an Energiesprong solution.  18,000 homes have already been done.  Already the cost of installation has halved; but we need to go further.  Industrialisation is the way to do this.  This is 2 to 3 years away.  The Dutch market is not big enough on its own to attract companies to invest in new components needed for industrialisation.  Hence the work being done through Transition Zero, an EU funded Horizon 2020 project to bring on other markets in Europe including the UK, France and Germany.

Already there are 5 or 6 Housing Associations with 100 homes between them in the UK looking to retrofit Energiesprong solutions.  The picture is similar in France and Germany.

Developments in London

Ben Coombes, Programme Manager GLA

The Mayor’s ambition is that London should go beyond existing climate change targets and become a carbon neutral city by 2050.  As housing is responsible for 36% of London’s carbon emissions we need to find a solution to tackle them.

Energiesprong is the most suitable fit to deliver these savings.  To this end London will match fund an Energiesprong retrofit of 10-12 properties through the RE:NEW programme.  This will be done by working with Local Authorities and Housing Associations.  In future is hoped to do more.

Question and Answer Session

Are you speaking to planners?

Yes, NCH attended a collaborative workshop last week on the design brief.  The Design Manager for Nottingham City Council came to the workshop and was a part of the discussion.

Can Energiesprong be done internally?

Energiesprong is associated with exterior cladding, but what is important is the performance specification.  The solution is flexible. In the Netherlands one private house has been insulated internally at the front and externally at the rear.  The challenge of working internally is to ensure air tightness and avoid thermal bridges.

What is the business case?  £75k for the retrofit of a 1960’s property is not economic.  It would be more economic to demolish these properties and rebuild.

It is accepted that £75K per property is not economic. That is why we are focusing on getting to scale; as this will bring the cost per property down.  Also, it should be remembered that there are savings on maintenance for 30 years which should be bought into the equation.

Key Learnings

  • Retrofitting existing homes so that they are fit for the future is a massive challenge
  • Energiesprong which delivers a whole house retrofit with a 30 year performance guarantee can deliver what is needed
  • Early engagement with procurement teams & tenants is crucial
  • The cost of an Energiesprong whole house retrofit will come down with scale & the industrialisation of the process