Areas We Serve: Home Extension Guides for Every London Borough

Studio MASS works with homeowners across London, and we are publishing a planning and cost guide for every borough we serve. Each guide answers the same three questions: whether you need planning permission, what an extension realistically costs in 2026, and what a well-run project involves from first idea to finished build.

The guides published so far:

• Home extension design in Haringey

• Home extension design in Camden

• Home extension design in Barnet

• Home extension design in Hackney

• Home extension design in Islington

• Home extension design in Enfield

• Home extension design in Wandsworth

• Home extension design in Ealing

• Home extension design in Brent

• Home extension design in Harrow

New guides publish every week through September, covering Richmond upon Thames, Kingston upon Thames, Merton, Lambeth, Southwark, Lewisham, Greenwich, Bromley, Croydon, Sutton, Hounslow, Hillingdon, Hammersmith and Fulham, Kensington and Chelsea, Westminster, Tower Hamlets, Newham, Waltham Forest, Redbridge, Havering, Bexley, Barking and Dagenham, and the City of London. This page is updated as each guide goes live.

Not sure where to start? Tell us about your home and your brief through our short questionnaire and we will arrange a free thirty-minute call.