Energiesprong and Carbon Co-op

Community Retrofit
Large scale retrofit programmes that aim to increase energy efficiency of existing housing, primarily social housing and government-owned housing stock

Context

Retrofitting—the process of upgrading and modernising existing buildings to enhance their climate efficiency—is a crucial strategy for rehabilitating older housing stock. As the fabric of the city ages, retrofitting offers a way to reduce the environmental footprint of heating and cooling older buildings. Through installing insulation, solar panels, climate control systems, and other energy sources such as heat pumps, retrofitted homes can significantly lower their energy consumption and greenhouse gas emissions. This approach provides economic benefits through decreasing utility bills for homeowners as well as reducing demolition and its associated environmental costs. Questions remain, however, about strategies for retrofit to be scaled up in an economically-sustainable fashion.

Practice

Energiesprong is a global retrofit alliance that originated in the Netherlands but which has retrofitted dwellings in the UK, France, and USA. The Energiesprong retrofit programme transforms existing homes into net-zero energy residences, generating the energy needed for heating, hot water, and electrical appliances. The retrofit includes the addition of prefabricated facades, insulated rooftops with solar panels, as well as smart heating and ventilation systems. The process comes with a long-term performance warranty of up to 40 years for both indoor climate and energy performance, and the works can be completed in less than 10 days. So far, Energiesprong have retrofitted over 5000 houses in the Netherlands, over 4000 in France, and almost 500 in the UK.1‘Energiesprong Global Alliance explained’, Energiesprong <https://energiesprong.org/about/>.

One barrier to retrofit in the past has been the lack of a clear calculation method to establish the cost savings to residents, and the high level of investment required for residents to undertake a retrofit process on their home. Financing for Energiesprong renovations is typically covered by future energy cost savings as well as the budget that the housing association has allocated for planned maintenance over the next 30 years. Rather than paying their energy bills separately to private companies, residents pay an energy service plan to the housing association, similar to a phone bundle, that guarantees an indoor temperature, a hot water allowance per day and power for lighting and other electrical appliances.2‘What is the Energiesprong approach?’, Energiesprong UK <https://www.energiesprong.uk/how-does-it-work>. The housing association uses this income to pay for the retrofit. Guaranteeing the energy performance of the house, the exact energy costs post-retrofit can be calculated so that the housing association can set the rate for the energy plan lower than that of an energy supplier, but with some surplus to recoup the retrofit costs. Housing association residents are therefore not required to contribute to costs directly upfront. Energiesprong offers a 30-year construction and energy performance warranty, aligning the cost of retrofit with expected maintenance and energy savings.

Another organisation, Carbon Co-op in Manchester, UK, have also been researching ways to unlock financial investment in large scale retrofit including calculating the savings from retrofitted homes and selling those savings to long-term finance providers. In return, consumers receive upfront investment in the cost of the retrofit.3‘Retrometer – SIF project’, Carbon Co-op <https://carbon.coop/portfolio/retrometer-sif-project/>.

Scaling up retrofit through such alliances is essential in order to increase energy efficiency of older dwellings and other buildings. Initiatives that enable retrofit at scale, solving problems with upfront construction costs are an essential part of the development of a retrofit ecosystem that can decarbonise existing housing stock. Retrofit at scale brings with it complex interrelationships, both technical (how the new technologies interact with the old fabric) and social (how to work with and around residents). The role of the architect therefore shifts from the traditional guise as innovator of the new to that of organiser, facilitator, and negotiator—all skills that require imagination and coordination.

Notes