The former Angel Centre in Clerkenwell, an unloved 1980s office building facing demolition, was successfully transformed into a multi-award winning, eye catching and modern hub of activity which, with its mix of public atrium, café, bespoke works of art and rooftop terraces is redefining the working environment.

The footprint of the building has been imaginatively extended by the architects Allford Hall Monaghan Morris. The old St John Street frontage failed to utilise the aesthetic possibilities of the site. Now it takes up the curve of the road and the forecourt created by the curve has been repaved and replanted to complement the configuration of the building.

By re-using the existing frame, the project saved 7,400 tons of CO2 of embodied energy ( equivalent to running the entire new building for 13 years) while providing 40 per cent more functional area. The concrete frame has been re-wrapped with a highly energy-efficient glazed skin.

As radical as the re-structuring of the building, the landscaping also required intensive cooperation between the architects, the developers Derwent London, local authority – London Borough of Islington, and landscape architect Johanna Gibbons of J & L Gibbons. Some of the existing trees, originally planted too close to the building and consequentially misshapen were removed and replaced by specially selected semi mature London Plane trees.

To meet the architect’s concept of the overall landscape environment GreenBlue Urban Ltd, collaborating with the landscape architect, designed and manufactured four bespoke galvanised tree grilles with a significantly reduced visual impact. Blending in with the 60mm Granite sets, a feature of the project, the grilles, almost 2.2m square, were of a very strong but shallow design to avoid conflicting with the root ball of the semi-mature trees. Main contractor BAM and sub-contractor J Browne ensured that all tree root growing areas were protected at all times from soil compaction.