Erect Architecture has led the refurbishment of Quadrant House, a 1960s modernist office building with ground floor retail units located in Caterham town centre (Surrey). The building’s length of 115m gives it a key presence on the high street.

Quadrant House was acquired by Tandridge Council to preserve much needed space for local businesses when the building faced being converted to flats by its previous owner. Following the purchase, the Council successfully raised funding from the Coast to Capital Local Enterprise Partnership to kickstart essential building improvements and help to revive the high street. The key drivers for the project were supporting local economic growth and achieving an exemplar sustainable retrofit.

Spatially, the project provides attractive and affordable workspaces for local businesses, a new business incubator, new communal areas including roof terraces, and an improved appearance for the shopfronts at street level through a new retail design code.

The design also enhances the environmental performance of the building. Erect Architecture worked closely with BTP Consultancy to implement best practice retrofit measures, primarily building envelope upgrades and transitioning towards an all-electric heating and cooling system which will in future be supported by on-site electricity generation. The team devised a strategy for how further environmental enhancements can be made through a phased approach, as the Council is able to secure further funding.

Externally, a new green wall on the main elevation provides greening to the high street, enhancing biodiversity and improving air quality. The green wall is irrigated using harvested rainwater run-off from the main roof.

Structurally, working with an existing 1970s reinforced concrete frame presented challenges which the team had to work through carefully. The main concerns were the extremely tight margins for additional loadings, which presented constraints for the new terrace, green wall and escape stairs.

To improve accessibility, new larger lift cars and escape stairs were designed and installed. A separate ongoing High Street enhancement project will further improve access when completed.

The project was designed to a very tight budget which necessitated a phased approach. Phase 1 included the refurbishment of communal areas including new toilets and showers. As additional funding became available Phase 2 commenced, which comprised thermal improvements to the building envelope including new windows and doors, the refurbishment of unoccupied office suites, new larger lift cars and escape stairs, terraces for building occupants and the green wall. Phase 3, the upgrade of the High Street public realm is currently underway. In future phases the remaining office suites and retail units will be improved, and photovoltaic panels installed on the main roof.

The completed refurbishment will result in a fully insulated, electrically serviced building with enhanced accessibility and safety; modern, flexible office spaces, and a rainwater-fed green wall. The client and local people are excited and proud of the transformation this project achieves for Caterham.