This Clerkenwell office refurbishment and extension improves a character Victorian warehouse building. The scheme provides six workspaces to the upper floors and a furniture showroom at ground and basement.
The building is enlarged with a three storey extension to the rear and an additional, set back rooftop storey above. Internal areas are increased by nearly 50% from 7,600 sqft to 10,150 sqft. A new level entrance, lift and reconfigured stair are inserted to improve accessibility to all levels.
The new floors, roof and external walls are of lightweight construction to enable the existing foundations, cast iron columns and masonry walls to carry the increased loading without modification.
The rear of the building faces onto Albemarle Way, a narrow medieval road. Here, articulated facade details are inspired by the recessed brick panels, decorative lintels and visual weight of adjacent Victorian buildings. The narrow width of Albemarle Way dictates that the building is seen from a low angle, enhancing the effect of the articulated facade depth.
The emissions rate for all new build elements is 15 kgCO₂/m²/year which is a 34% improvement on the Building Regulations requirement. This gives a reduction of 3,000 kg/year of CO₂ emissions.
In the retained parts, all sash windows will be replaced with triple glazing to provide better u-values and airtightness. Retained areas of solid masonry walls are insulated internally.
Overheating analysis allowed the optimisation of the facade to provide good natural light without overheating or glare, both currently a problem due to large areas of south facing glass. An MVHR system will reduce traffic noise and also improve indoor air quality by filtering NO₂ and particulates from the busy city road outside.
New zoned heating systems and low energy LED lights are specified throughout. Showers and bike stores are provided at each level to encourage cycling. At roof level, PV panels provide renewable energy and a green roof reduces water run off.
Strip out is underway and the building has begun to reveal its essence. The removal of accumulated objects from the last 150 years allows a new focus on the inherent beauty and clarity of structure: a heavy mass of brick piers, iron columns and timber joists designed to bear great weight. Oversized sashes and clerestory windows wash newly revealed, time-worn surfaces with natural light.
Ben Ridley, Matt McKenna
FORM Structural Design
Clerkenwell Road, London EC1M