The Underwood is a local housing project in South London that showcases how Net Zero Carbon affordable houses for local people can be delivered on time and to budget.
This project demonstrates how the delivery of Net Zero Carbon houses does not need to be overly complicated, expensive or time consuming. This project demonstrates that with the right approach, inspiration and motivation, we can achieve Net Zero Carbon affordable housing, using MMC (SIPs panels) with limited additional cost above a baseline Building Regs compliant scheme and a traditional delivery method.
The client brief was clear from the outset that fuel poverty for their affordable rented tenants was a significant issue and so the houses needed to ensure that residents fuel bills stayed below £200/ annum. In addition, Greenwich Council has declared a climate emergency within their borough and so all new houses that are delivered for them need to be Net Zero Carbon.
The Underwood provides eight houses for affordable rent for the local community. Seven of the houses are 2 bed (4 person) and one is a fully wheelchair adapted (Building Regs M4(3)) 3 bed (5 person) house. All of the houses exceed the Nationally Described Space Standards and all the 2 beds also meet Building Regs M4(2).
The team developed a concept that would create a friendly and welcoming street for the new residents with the principle of a terrace of houses with the ground floor kitchen windows overlooking the street and the living room facing the garden. The external works are shared surfaces with planting and trees to the south boundary. We very much feel this could be a friendly street where the front doors could be left open and people could sit out the front as well as the back.
We followed the ‘be lean, be clean, be green’ principles with a fabric first approach. We used offsite manufacture timber SIPs panels. Building the SIPs in a factory environment ensures that there is near zero waste, the materials are sustainably sourced and the final output has low embodied carbon.
To ensure we achieved Net Zero Carbon, the SIPs panels enabled us to uprate the thermal performance of the walls and significantly reduce the air permeability of the houses. We incorporated triple glazed windows and doors to complete the ‘be lean’ fabric first improvements.
We created clean energy by using Air Source Heat Pumps for the heating and hot water and Mechanical Ventilation Heat Recovery to reduce the amount of heating we would require. We finished with renewable energy source from Photovoltaic Panels on the roofs to provide electricity to offset the usage from the ASHPs.
Cllr Anthony Okereke, Cabinet Member for Housing, The Royal Borough of Greenwich, said:
“This development is an excellent example of the new generation of council homes we are creating with our Greenwich Builds programme. Being net zero carbon these homes not only fulfil our commitment to tackling the climate emergency but will also address fuel poverty for our social rented tenants by reducing electricity bills to as little as £200 per year. We are delighted with how the architectural design has transformed a disused garage site into innovative and much needed council homes for local people on our housing waiting list.”