The initial response was to follow the logic of the client and apply for planning permission to convert the existing loft to a bedroom and to create a new basement by excavation. This was achieved without too much difficulty as we worked within the current local borough planning guidance. However as we progressed the design two issues emerged that would change this approach.
Firstly the costs of building the basement which would require full excavation, underpinning and waterproof tanking, would add approximately £120,000 to the project which exceeded the planned budget. Secondly, the project took place at the time the Westminster government relaxed planning controls for rear extensions and loft conversions. The new ‘permitted development rights’ were not clearly understood by the local authority at the time but as the project proceeded through the planning stages it became apparent that significantly increased roof space might now be possible.
The local authorities own guidance on roof extensions restricted them to within the boundaries of the main roof structure over the front terraced portion of the house. The new permitted development rights however now allowed an L shaped configuration that could extend over the rear slightly lower two storey ‘outrigger’ which feature in much of London’s original housing stock.
It didn’t take long for the client to make the choice to follow this new development as the building of additional roof space was a considerably cheaper option than excavating the basement. The focus of the design of the project changed as the project developed due to changing legislation. This was a challenge to overcome, but using our proven expertise we navigated our way through the planning process to the clients ultimate advantage.
The roof design of this project changed significantly as the project proceed-ed. As the house was overlooked by a block of flats to the rear of the property the client felt that the window openings should be restricted to standard window opening sizes. Dark coloured plain tiles were chosen for the cheeks of the dormer roof extension which match the colour of the existing roof. This helped to blend in the considerable additional volume of building at roof level with the existing house.
The plans for the extension at ground level remained constant throughout the project. At ground level the key design decisions made were, firstly for the kitchen / dining area to be moved to the front room of the house and for the existing kitchen area at the rear to be combined with a long side extension thus creating a larger living area with a direct connection to the garden.
A light lean-to glazed roof over the extension would provide lots of natural light to the living space while fully glazed windows and doors would strengthen the relationship with the garden. A wood burning stove creates a very homely feeling and the media centre integrated with the wall to ceiling cupboards provides a clean solution by hiding the inevitable plethora of wires and sockets so as to relax to the pleasure of both sound and vision.