Builders in Twickenham

The Victorian and Edwardian houses of St Margarets and central Twickenham usually have a back addition with a side return beside it, a good sized garden and a loft that can be converted. The interwar semis towards Whitton tend to have a hipped roof, a side passage and a garden long enough to extend into. Both make good family homes once the ground floor opens up and an extra bedroom goes in upstairs.

Whatever the age of the house, we start with a proper survey, so the state of the structure, the drainage and the services is known before the design is fixed and the price is agreed.

On a terrace, most kitchen extensions fill the side return or wrap round the back as one room facing the garden: see our guides to side return extensions and wraparound extension ideas. On an interwar semi there is usually room for a full width single storey extension across the back, sometimes with a side extension into the passage, or a two storey extension.

Our house extensions page explains how we take an extension from survey to handover, and our free extension planner lets you try a layout on a home like yours first.

On an interwar semi with a hipped roof, the usual loft conversion is a hip to gable conversion with a rear dormer, which turns the sloping side of the roof into a full gable wall and makes room for a staircase over the existing one. On a Victorian or Edwardian terrace it is usually a rear dormer, sometimes extended over the back addition. Our loft conversion cost guide and loft conversions page explain the options.

Twickenham is in the London Borough of Richmond upon Thames, so applications go to Richmond upon Thames Council. The borough has many conservation areas, including Twickenham Riverside and Strawberry Hill, and inside them a dormer loft conversion is not permitted development and needs planning permission. Outside them, many rear extensions and loft conversions on houses can go ahead as permitted development, and a lawful development certificate confirms it in writing.

Flats and maisonettes have no permitted development rights, so extending a flat always needs an application. We check your address at the start, prepare the drawings and manage the application, along with any party wall agreements the work needs.

Typical London jobs priced on our estimator in October 2026, ex VAT and indicative rather than a quotation:

• A single storey extension of about 20 m² of new floor, flat roofed, plus making good the room it joins: around £57,000.
• A rear dormer loft conversion: £68,000 to £81,000.
• New above ground space at a standard specification: £2,650 to £2,900 per square metre of new floor.

Kitchen units, worktops and appliances are priced separately. Our minimum for a complete extension project, including finishes and fittings, is around £85,000. Our house extension cost guide and loft conversion cost guide show the full breakdowns, and the free estimate prices your own project in two minutes.

Our office is in Chiswick. Our nearby work includes the loft conversion at Seven Oak in Chiswick, which added a bedroom, a bathroom and a study, and Woodside in Wimbledon, where a loft added three bedrooms and two bathrooms. For homes nearer the town of Richmond, see builders in Richmond.

Every project runs as one design and build service, with a single team responsible from concept to completion. We carry £10M public and employers' liability cover and agree the programme, access and working hours with you before the build starts.