Do I need a Party Wall Agreement?

If your extension involves excavating within 3m of a neighbour's structure, or building on or near the boundary, the Party Wall etc. Act 1996 applies and you'll need to serve notice on your neighbours. It's a routine process. Our party wall guide explains it step by step, and we have experienced party wall surveyors where needed.

Do I need planning permission for an extension?

Not always. Single-storey rear extensions of up to 6m (semi-detached and terraced) or 8m (detached) can often be built under Permitted Development via the prior approval process. Side extensions, two-storey extensions and anything beyond these limits usually need full planning permission. We have a more in depth article on planning permission here. We manage the whole process on your behalf, including drawings and submissions. And a word of caution: since April 2024, unauthorised building work can face enforcement action for up to 10 years, so it's never worth skipping the proper route.

How much does a house extension cost?

As a general guide, single-storey extensions in and around London typically start from £2,500 to £3,000 per square metre for a good-quality build, but this is excluding the costs of kitchens, bathrooms and the ever-dreadedVAT. Two-storey extensions tend to offer better value per square metre because you're doubling the space over one set of foundations and under one roof. We provide itemised, fixed-price free quotations so there are no surprises.

How long will an extension take to build?

A typical single-storey rear extension takes 10 to 14 weeks on site, and a two-storey or wraparound extension 14 to 20 weeks. Before that, you’ll also need to allow time for design, planning approval and structural calculations. We'll give you a realistic programme at the outset and keep you updated weekly. Our house extension process guide explains more.

Can I live in my home during the build?

Yes, and most of our clients do. We section off the work area, maintain access to kitchens and bathrooms for as long as possible, and keep the site clean and secure at the end of every day. For kitchen extensions, we can often set up a temporary kitchen area to keep disruption manageable.