VICTORIAN HOUSE BASEMENT EXTENSION AND RENOVATION
HAMPSTEAD, LONDON 2016-2019
“How to bring natural light into the interior” was the biggest challenge of this large-scale extension and renovation project at a substantial Victorian house in Hampstead.
The works included vertical extensions: one up into the loft, and a second downwards into the basement; along with complete interior refurbishment.
It is a common problem for horizontal extensions of period properties to result in darker rooms at the middle of the building, and a division between the front and back of the house. In this project, with extensions above and below the existing house, there was an even more difficult issue of how to maintain good levels of natural light at the centre of the plan.
A 1/50 scale building model was produced at the very beginning of the project to investigate possible solutions. The existing house had a rather complicated arrangement of levels, with a half-storey level difference between one side of the building and the other. As a result, the existing rooms are staggered to either side of the central staircase, and accessed from alternating mezzanine levels.
The outcome of the initial investigations was a design solution involving three forms of top light: a large skylight at the top of the central stairwell with a transparent glass staircase below it; a large conservatory above the dining space at basement level; and a series of rooflights and high-level windows around the perimeter of the basement.
As well as maximising natural daylight within the house, the physical model enabled us to identify areas within the building that could be rationalised in order to maximise the height of each room.
The central glass staircase, constructed to a bespoke design, allows natural light to penetrate the interior of the house, from the top of the extended loft space, right down to basement level, fitting around the unusual level differences on each floor. To distribute daylight from this central lightwell, a series of ‘internal windows’ were also introduced, some even at a very late stage, during the construction process. These internal windows included some new openings on to the staircase, and some existing door openings that were converted to full-height windows on account of the new internal arrangement. These transformed openings became curios, reminiscent of the historic rooms and leaving evidence of how the house used to be arranged around the old stairwell. The bright new stairwell has become a hub for family life with increased permeability between rooms and greater linkage between the staggered spaces.
In contrast to the central rooflight, the conservatory structure, built in timber and glass, was designed to be in keeping with the external character of the existing house and the surrounding Victorian neighbourhood. Below it, there is a large double-height basement space filled with vast amounts of natural light. This new dining area has become a new core of family life within the house. A new contemporary kitchen is located adjacent to it, with quieter family areas on the other side of the open floor plan, where there are lower ceilings, and a series of rooflights and high-level windows that bring in a more subdued, reflected daylight.
Careful investigation of the existing building, through physical model-making and spatial imagination, enabled us to find effective ways of bringing natural light into the heart of the property and then distribute it to each room. The resulting basement extension, although located at the deepest part of the old Victorian house, is a grand, open, light-filled space ideal for modern family living.