5-7 Belsize Grove Retrofit

Posted on 18/5/2024

David Thomas, lead Committee member on retrofitting, writes:

Upgrading work is nearing completion on this Camden Council-owned block of 58 bedsits and self-contained flats. Most of the residents have been able to stay in their homes while the work was carried out.  The two original mid-19th century buildings were converted in the 1950s, with a connecting block added in the 1980s.

In late February, Sim Dhinsa, Camden’s Retrofit Programme Manager, accompanied by a representative from their energy consultants and main contractor, kindly gave three of us a guided tour of work in progress. We were impressed.

The thermal mass of the building has been upgraded using wall insulation fitted externally on three of the elevations and internally on the fourth where space was limited. This has ensured the minimum disturbance to the residents and avoided any reduction in the usable internal floor area of most of the flats. It extends up to the soffit at the underside of the roof and ties in with additional insulation within the roof area. A render finish has been applied externally on the three elevations.

The original single-glazed timber sash windows have been removed and replaced with thermally improved, slim, double-glazed timber sash windows to match. The existing internal timber door sets with single-glazing panels have been replaced with more robust and thermally efficient double-glazed ones. The improvements to the windows and doors were necessary to meet the revised approved documents “L- Conservation of Fuel and Power” and the London Borough of Camden carbon climate emergency targets.

New architectural features have been installed on the front and rear elevations. Mouldings with stone effect form new quoins at wall corners, window surrounds, dentils and bands to recreate the appearance of the original two detached pairs of houses. The rear elevation is less decorative, with quoins, window surround and bands.

With the external walls upgrade and the improved airtightness of the building, it has been necessary to provide adequate ventilation to prevent overheating and high moisture content.

The mechanical ventilation system in the communal areas has been repaired and extractor fans now replace the airbricks in the individual flats.

Photo-voltaic panels have been installed on the front elevation roof to provide renewable energy. The building is four storeys high so that their visual impact from the street level will be minimal.

The Council and its residents were consulted throughout to ensure that the design is the best solution to improve thermal performance, reduce carbon emissions and combat fuel poverty.

In a separate scheme, heat pump adopters open up their homes to encourage other UK householders considering swapping their gas boiler for an electric heat pump: they can see how they work by visiting an early adopter in their area. A new service aims to help would-be heat pump adopters to book a visit with households that already have one installed through a website launched by the innovation charity Nesta. The site, VisitAHeatPump.com, allows potential users to locate one of 150 households that have signed up to show them their low-carbon heating systems.

Stay in touch on retrofit@belsize.org.uk.