In Practice: The UK's first Energiesprong homes
A pioneering new pilot project in Nottingham aims to make select households ultra-low carbon and fit for the future by renovating them using the 'Energiesprong' techniques used in the Netherlands.
There is an ambition in the UK to ensure that all buildings are low or zero-carbon buildings by 2050. However, a study by the Association for the Conservation of Energy found that the UK is amongst the highest in Europe for fuel-poverty and has one of the most energy-inefficient housing stocks on the continent.
With more than 26,000 homes, Nottingham City Council believes it has a “commercial imperative” to find ways to retrofit existing houses to a near-zero emission standard in a way that is affordable and easily replicated for potential new builds.
Last week, 10 homes in Sneinton became the first Energiesprong houses in the UK. Energiesprong is an innovative approach to housing refurbishment that delivers net zero energy performance to existing houses in under a week, without residents moving out, at an affordable cost.
The Energiesprong approach upgrades homes with a new exterior, fitting the outside of the building with new walls, windows, a solar roof and new electrical heating systems. Developer Melius Homes and social landlord Nottingham City Homes have worked together on the scheme, with solar photovoltaic roofing supplied by UK manufacturer, Viridian Solar.
Around 2,000 Energiesprong homes have been completed in the Netherlands, of which around 60% were renovations of existing properties and 40% new builds. In Nottingham, the process saw each house surveyed externally within a millimetre of accuracy using laser scanners.
From there, highly-insulated timber frame cladding is lifted into place by a crane and attached to existing walls. The solar roof is then attached on top of the existing roof. Windows and doors are removed and replaced, while heat pump, solar thermal or electric panel heaters replace older systems. All projects are covered by a 30-year warranty regarding energy performance.
The new fittings will drastically reduce household energy bills and make the homes warmer, although the first set of data on the expected improvements is yet to be published. A total of seven houses and three bungalows have been transformed through the scheme.
Instead of paying gas and electricity bills, residents now pay a reduced energy services fee to the social landlords. The guaranteed income, which accounts for savings on planned maintenance costs, can then be used to fund further Energiesprong projects. It is hoped the projects can eventually be carried out without government support, boosting attraction for financial markets.
Energiesprong UK, the organisation overseeing project developments in the UK, suggests that the refurbishment process must be carried out at around £40,000 to be self-financing. Currently, the Nottingham scheme was around £75,000 per unit, with additional “top-up” income provided by other organisations.
The seven houses were fitted with 21 solar modules each at around 5.46kWp per house. The three bungalows were fitted with 16 modules each at 4.16kWp, this equates to 50.7kWp across the entire pilot.
The Energiesprong programme is part of the next phase of Nottingham City Councils Greener HousiNG programme – a home energy efficiency scheme that aims to reduce individual household energy bills by £400 annually through subsidised energy saving measures.
To date more than 6,000 properties have benefitted from the scheme to improve the energy efficiency of the city’s domestic housing stock. Nottingham City Homes and Melius Homes have an agreement in place to create a further 400 Energiesprong homes.
The current pilot is part of a smart city solutions cluster, delivered by Nottingham during a three-year period under the European-funded REMOURBAN project, which aims to showcase sustainability within regeneration projects in towns and cities.
Following initial success in the Netherland, the concept is being exported to France, Germany, Luxembourg, the US and the UK. In fact, Clarion Housing Group and Moat Homes have found a set of properties in London and Essex which they have identified for Energiesprong renovations.
Clarion has identified 10 properties, five of them in Borehamwood and the others in Bromley, which are suitable for net zero energy refurbishments.