House extension in Barnsbury

Connect the added space to the existing home.

Start with the house extension brief

Begin with how the new space will meet the old rooms, garden and circulation. A measured brief should record boundaries, levels, existing drains, neighbouring windows and the parts of the building you intend to keep.

Develop daylight, structure and services alongside the floor plan. Agree which openings and finishes are included, how the existing home will be protected during construction and which decisions need surveys or approval before a quotation.

The local building context

Islington’s Barnsbury Conservation Area Design Guidelines, dated January 2002, call it the largest conservation area in Islington, declared to be of outstanding importance. They describe formal late-Georgian and early-Victorian residential developments, naming sequences of squares and terraces such as Lonsdale Square, Gibson Square and Thornhill Square, with mature trees and planting in many of the squares. They describe the area as predominantly residential, with shopping frontages on Liverpool Road and Caledonian Road, and say the council wishes to retain all listed and locally listed buildings and all other 18th and 19th century buildings there.

Islington’s Urban Design Guide names Barnsbury among the Georgian-era developments of squares, terraces and semi-detached villas built for the middle classes, completed by the mid-19th century as early Victorian building continued the Georgian style. The Islington Local History Centre’s Barnsbury trail dates Cloudesley Square, the earliest Barnsbury square, to 1826 and the first Thornhill Estate houses, 76–86 Richmond Avenue, to 1829. Lonsdale Square was designed in 1835 by Richard Cromwell Carpenter, College Cross and Barnsbury Square were developed in the 1830s, and Thornhill Square was begun in the 1840s.

Barnsbury is the name of an Islington ward, a conservation area and a housing estate that Islington’s Site Allocations list as adjacent to, not within, the Barnsbury and Regent’s Canal West conservation areas. Neither the name nor an N1 postcode settles the council, a conservation boundary, a listing, Article 4 coverage or the consent route. Confirm the council with the official lookup, then check Islington’s conservation and Article 4 map, the list entry, the local list, the lease or title and the planning history for the address.

Local design and consent context

Islington’s table gives the Barnsbury Conservation Area (CA10) a designation date of 1 April 1969, a last amendment or extension on 22 April 2004 and current design guidelines adopted in January 2002. The guidelines say the council will operate special policies there to preserve and enhance the area’s special character and appearance. As the boundary was last changed after the guidelines were written, check the address on Islington’s current map. Regent’s Canal West (CA17), which the Site Allocations also list as adjacent to the Barnsbury Estate, was designated on 27 January 1981 and has its own guidelines of January 2002.

For a refurbishment, the guidelines bear most on the outside. Traditional roof extensions may be permitted on the properties listed in Schedule 10.2; otherwise none visible from any street level position will be permitted, including long views. New or enlarged dormers and rooflights are not permitted on the front or side slopes of exposed pitched roofs; plant rooms, air conditioning units and water tanks at roof level are opposed where they can be seen from the street or public space; and full width rear extensions above one storey are not normally permitted. The council seeks to keep porticos and traditional ironwork, and will not give permission to alter or remove original or traditional front walls and railings.

Islington’s Urban Design Guide, adopted in January 2017, says roof extensions anywhere along an unaltered roofline in a conservation area will not generally be acceptable, that acceptable roof extensions on terraces or villas must be restricted to a single storey, and that flat mansards are usually not acceptable in conservation areas. It asks for chimney stacks to be retained, and for butterfly parapet profiles to be kept where they are a characteristic feature.

Access and site planning

Decide where deliveries will stop and where waste will wait. Islington needs a licence for scaffolding, hoardings and building materials on the highway, and an obstruction on a red route such as Upper Street needs Transport for London’s permission. Only a company holding a waste carriers licence can apply for a skip licence, which takes five days to process. Islington’s list of traffic-sensitive roads puts Barnsbury Road, Caledonian Road, Liverpool Road and Offord Road in the category where a skip should stand in a suspended parking bay, and marks Upper Street and Pentonville Road for Transport for London to license. Bay suspensions need at least 10 days’ notice for Pay By Phone bays and 14 days for others, and Islington cannot suspend yellow lines.

Continue planning

The Barnsbury area guide · House extension across London · Hampstead Architecture & Planning · Hampstead Chartered Surveyors

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