Renovating a London townhouse

A London townhouse is a difficult building to renovate well. It is tall and narrow. It has been altered before. Much of what makes it worth owning is protected. Here is what the work actually involves, and where it usually goes wrong.

The plan is the problem, not the floor area

Most of these houses were built with a service stair and small cellular rooms. The kitchen was in the basement. Families do not live like that any more. The work is usually about circulation and daylight rather than square footage. Where does the stair land? How does the back of the house open to the garden? Does the middle of the plan get any light at all?

Heritage detail has to be recorded before it is touched

Cornices, architraves, shutters, chimneypieces and the original joinery are what a buyer pays for. Photograph and measure them before strip out. They are easy to lose and expensive to reinstate. Where something has to come out, take a mould.

The services are the hidden project

A period townhouse will usually have undersized electrical capacity and old pipework. It will also have poor drainage falls and no ventilation strategy. Modern heating, cooling, lighting control and data all need space. That means space in floors, ceilings and risers. The original building never allowed for it. Settle the MEP design before the finishes are chosen. Otherwise you will lose ceiling height to it later.

Structure and neighbours

Removing a spine wall engages the structure. So does lowering a lower ground floor or building a rear extension. These usually also engage the Party Wall etc. Act. Start the notices early. The programme is built around them rather than the other way round.

Sustainability, without changing the elevation

Insulation, airtightness and glazing performance all have to improve. They must do so without altering what the street sees. That is a design problem rather than a shopping list. It is the part of a conservation-area renovation that takes the most thought.

Completed examples

See the Chelsea townhouse, the townhouse basement and extension and the Knightsbridge townhouse. They are finished work. You can also look through the whole portfolio.

You may own a London townhouse. You may be working out what to do with it. If so, tell us about it.