Home Extension Builders in Westminster

Westminster sits at the top end of London's construction cost range. Single-storey rear and lower-ground extensions typically start from £60,000–£80,000, with double-storey or listed building projects often exceeding £130,000. The combination of central London labour rates, strict material requirements under conservation area and listed building policies, and the logistical cost of building in a dense urban environment all push costs higher than most other parts of the city. Buildaway provides a fully itemised breakdown after a free site visit so there are no unexpected figures once work begins.

Almost always yes. Westminster City Council administers some of the tightest planning controls in the country. The borough contains over 50 conservation areas and thousands of listed buildings, and permitted development rights are removed across large parts of the residential stock. Extensions to terraced townhouses in areas like St John's Wood, Bayswater, and Paddington all require full planning applications, and listed properties need Listed Building Consent on top. Buildaway prepares thorough submissions including heritage assessments and material specifications that meet Westminster's design requirements.

Westminster's residential stock is dominated by Georgian, Regency, and Victorian townhouses with existing lower-ground floor levels which makes rear extensions at garden or lower-ground level the most feasible and planning-friendly option in most cases. Infill additions within return wings and internal reconfigurations that improve circulation without altering the external form are also regularly achievable. Full double-storey rear extensions are more difficult to secure approval for in conservation areas. Buildaway designs to what Westminster will actually approve rather than what looks good on paper.

Planning determination typically takes 10–14 weeks for a standard householder application, and 16+ weeks where Listed Building Consent is also needed. On-site construction runs 14–18 weeks for single-storey and lower-ground extensions, longer for more complex structural projects. Westminster's working hour restrictions and logistics licensing requirements also affect how efficiently a site can be run. We build a realistic programme covering every stage so you know what to expect before anything starts.

Yes. A large proportion of Westminster's residential properties are Grade I or Grade II listed, and even unlisted properties within a listed building's curtilage can trigger consent requirements. Buildaway prepares Listed Building Consent applications alongside planning submissions where both are required, including heritage justification documents and material schedules that Westminster's conservation officers review carefully. We manage all council correspondence and respond to officer queries directly.

Yes the entire project runs through Buildaway from the first drawing to Building Control sign-off. Our architects work to Westminster's conservation standards, our structural engineers handle party wall and steelwork calculations, and our trades carry out the full build without any handoff to a separate contractor. In a borough where specification compliance matters as much as it does in Westminster, having one accountable team across design and construction makes a real difference to how the project runs.

Westminster requires licences for scaffolding, skips, hoarding, and contractor parking all of which need to be secured from the council's highways team before work begins. Working hours are restricted across the borough, and site management standards in residential streets and garden squares are expected to be high. Buildaway handles all permits and logistics coordination as a standard part of running the project, so you're not navigating Westminster's administrative requirements while also trying to manage a building site.