The 156-home development for Telford Homes on the Caledonian Road in north London regenerates a difficult embankment site
Jestico + Whiles has completed a 156-home scheme at 351 Caledonian Road for developer-contractor Telford Homes.
The 1.9ha site was previously a derelict railway embankment, purchased for the construction of the Channel Tunnel Rail Link (CTRL) into King’s Cross St Pancras station. This was completed in 2011 and now runs beneath the ground at a shallow depth. The practice developed and delivered the project following a design competition held in 2013.
The scheme comprises seven lightweight buildings sitting above the railway tunnel. Their massing forms a series of stand-alone pavilions within an integrated landscape featuring existing and extensive new trees and planting across the site.
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In order to build directly above the railway tunnel – in some places only 4m below ground – the scheme employs a prefabricated lightweight structural steel frame above a concrete raft foundation to minimise and distribute loading. The soil was tested for movement in the tunnels before and during the build – if any deflection was discovered, Eurostar trains would be at risk of being cancelled.
The use of the steel framing system allowed for extended column-free openings in the brickwork for balconies, as well as improving simplicity and efficiency in construction.
The project faced several challenges including the location’s designation as a Site of Importance for Nature Conservation (SINC), as well as being bounded by two railway lines.
This was one of the more complicated and constrained sites imaginable in London – limited access, a steeply sloped topography, adjacent to two railway lines with another just metres beneath the surface (itself adjacent to a culverted river), and all within a conservation area site rightly protected for its ecology in the most densely populated borough in the UK.
Our goal was first to protect and enhance the site’s natural ecology through sustainable development. The ‘pavilions’, with their compact footprints and dual or triple-aspect homes are placed into the sloping landscape to draw the green space into the heart of the scheme. In addressing the challenges of the linear building – to protect the site from the noise of the railway to the north, whilst also being lightweight enough to sit above the CTRL tunnel – we developed a layout that locates all ancillary spaces against the railway’s edge and provides generously sized homes with rooms and south-facing shaded balconies well in excess of current space standards. These homes have views out between the pavilions to the 2,400 newly planted trees on the site, and over the expanse of central London beyond.
Alex Luria, project architect, Jestico + Whiles
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Landscape consultant’s view
A holistic design approach from inception to completion has created a unique housing development where residential dwellings and managed ecology can be in harmony for the long term. A detailed landscape and visual impact appraisal (LVIA) at planning submission demonstrated that there would be no harm to the existing Site of Importance for Nature Conservation (SINC), landscape character or visual amenity.
The proposals provide an enhanced mosaic of habitats that inter-relate to encourage the passage of fauna and flora, thus enhancing wildlife value. This has provided a net gain in the number of habitats enriching the SINC which will increase in biodiverse value over time and with management.
The landscape proposals were carefully formulated by the team’s ecologist, arboriculturist and landscape architect. The design team visited Barnsbury Wood and Gillespie Park local conservation areas to take inspiration from habitats managed and created locally within the borough of Islington. The proposals have been formulated specifically to maximise biodiversity to the part of the Copenhagen Junction SINC lying within the site. The new urban native woodland is a significant contribution to the native urban woodland found in the borough.
Warren Standerwick, senior partner, Standerwick Land Design
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351 Caledonian Road is one of the most challenging sites Telford Homes has been involved with; constrained by the Channel Tunnel Rail LInk and Thames Water infrastructure running below the site, overground railway infrastructure running parallel with it, with steep slopes and a SINC designation. There were many issues the design team had to work around.
From the start, Jestico + Whiles enthusiastically embraced the opportunities of the site and found innovative and efficient ways to deliver the residential component sensitively and without detriment to the natural landscape. Telford Homes’ own delivery team worked with the architects around construction management, using modern methods of construction (MMC) to further minimise any disruption caused by the building works.
It was important, given the number of stakeholders involved, that the design team were able to deliver a proposal that responded to their voices. The resulting scheme has delivered a fantastic legacy of not only 156 new homes with 35 per cent affordable housing, but 2,400 new trees across the site along with an educational nature trail for local groups and schools, complete with bird hide.
Local school groups were on site during construction to plant within the SINC and to help plan the nature trail, proving this site is now part of the community.
Sophie Timson, former director, Telford Homes
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Start on site August 2015
Completion date August 2018
Gross internal floor area 16,326m²
Construction cost Undisclosed
Architect Jestico + Whiles
Structural engineer Conisbee
M&E consultant Mendick Waring
Quantity surveyor Telford Homes (in-house)
Project manager Telford Homes (in-house)
CDM co-ordinator Pellings
Approved building inspector NHBC
Main contractor Telford Homes
Landscape architect Standerwick Land Design
Structural steel frame Metek
Acoustic consultant Cass Allen
Cladding contractor BR Hodgson
Aboriculturist Sharon Hosegood Associates
CAD software used Revit
Annual CO2 emissions 10.45 kg/m²
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Environmental performance data
Percentage of floor area with daylight factor >2 48 per cent
Percentage of floor area with daylight factor >5 4 per cent
On-site energy generation 9 per cent
Annual mains water consumption 34.31m³ per occupant
Airtightness at 50pa 4.45m³/hm²
Heating load 28.91 kWh/m²/yr
Hot water load 21.33 kWh/m²/yr