Shortlisted in the 2017 BREEAM Awards, this development sustainably refurbishes and reimagines a group of six buildings to create 3,500m2 of high specification office space and four new luxury flats.

On the north side of Regent’s Park, partly occupying a Conservation Area, this collection of 19th and early 20th Century commercial buildings sits among Primrose Hill’s characteristic Victorian terraces. Our dramatic refurbishment and infill project will increase the buildings’ lettable office space, smarten their exteriors, and bring a new residential offering to the area.

Contemporary glass boxes inserted between the buildings will link them together, housing kitchens, bathrooms, lifts and stairs. This allows expansive, flexible and completely open-plan commercial space within the buildings themselves.

Four luxury flats will occupy a storey each of Leeder House, the 1000m2 former piano factory fronting onto Erskine Road. Its impressive façade is being retained, with floor plates replaced to result in spacious, modern flats fitted with gold standard bathrooms, kitchens and home automation systems.

We secured a change-of-land-use planning permission to allow former piano-factory Leeder House to convert from workspace to residential, which helped to fund the works. We increased the estate’s total floorspace from 2,600m2 to 3,400m2, including 800m2 of residential.

This project required a highly sensitive design solution to address a complicated urban context involving 28 neighbouring residential and commercial properties. Existing roof lines were respected to avoid potential daylighting issues to adjacent properties. Potential rights-to-light claims were avoided by cutting back the floor levels where necessary.

A carefully crafted masterplan respects the Primrose Hill Conservation Area, which cuts across the centre of the site to include four of the six buildings. From the outset, we conducted an effective community engagement programme that convinced an initially resistant Conservation Area Committee.

Camden Council welcomed our proposal, noting that the additions and alterations to the office blocks ensure the retention of employment uses at this site for years to come. The amount and flexibility of the space suits it to SMEs, helping continue the long-established relationship between small business and Primrose Hill.

Through site-specific feasibility studies, we market-tested and costed various usage options, including for residential to the entire site, as well as commercial and retail mixes. Our resulting proposal responds to and enhances the desirable area of Primrose Hill, bringing needed high-specification workspace to a largely residential area.

The scheme achieves an increased amount of lettable commercial space despite the conversion of Leeder House to residential use. This greatly assisted the client’s business model, with the sale of the residential aspect funding the redevelopment of the remainder of the site. The client will end up with a high-quality office development for a minimal outlay.

The Conservation Officer requested that the residential conversion building be retained. However, its timber floors had partially failed and needed to be replaced, requiring us to devise a way to restructure the building while retaining the façade. This involved inserting new steel columns, floor beams and floor slabs into the building, between temporary propping. The brickwork was cleaned up and the elevations restored to their original glory.

Existing buildings were cleared of extraneous accommodation to provide clean, lettable floorspace, with new service cores providing access links between the buildings. These bold, glazed sections complement the brickwork of the original Victorian and Edwardian buildings.

We achieved a highly sensitive design with a slick, capless curtain wall system employed on the cores and roofs, contrasting with the solidity of the historic factory buildings. All buildings have been taken back to bare walls, re-roofed, insulated, extended and fitted with new high performance windows throughout. A mix of natural and artificial slate roofs have been replaced with natural French slate.

The offices are set to achieve BREEAM Excellent and have been nominated as Highest Scoring Building in the 2017 BREEAM Awards, Offices (refurb & fit-out) category. The residential apartments are set to achieve BREEAM Very Good.

New green roofs will improve biodiversity and provide rainwater attenuation, while photovoltaic and solar thermal panels will provide 20% of the development’s energy. VRV heating and cooling will ensure energy efficiency, while the whole estate has been upgraded to incorporate best practice insulation values. All aspects of the development were designed and specified to achieve an extended lifespan of at least 30 years.