Built By Architects Who Know South West London
Why Homeowners Choose Design United Studio
Our architects are RIBA and ARB registered, with experience gained at practices including Foster + Partners. Being based in SW19 means we know local planning departments and conservation areas well, so extensions are designed for approval from the start, not redrawn after a rejection.
The Right Kind Of Extension For Your House
A side return extension opens a galley kitchen into a proper family space.
A rear extension pushes into the garden, a wrap-around does both, and a two storey extension adds a bedroom or bathroom above. We help you find the right fit for your house, garden, and budget.
Planning Permission Handled From Day One
Some house extensions qualify for permitted development, others need full planning permission, particularly larger rear extensions, wrap-arounds, and anything in a conservation area. We check this before the design begins, avoiding the delays that catch homeowners out later.
What Drives The Cost Of Your Extension
Cost depends on the size of the space, the structural work involved, the specification of finishes, and site access. There is no single figure that fits every project, so we talk through realistic budget ranges at your first consultation, based on what you actually want to build.
How We Work, Start To Finish
We start with a site visit and a conversation about how your household uses the existing space, then develop concept drawings through to planning submission. Once permission is granted, we support you through the build, working with your contractor to keep the design intact.
See The Difference Good Design Makes
Our Extension Projects
From side returns in Victorian terraces to full double storey rebuilds, our projects page shows the range of house extensions we have designed and delivered across South West London.
Our Track Record
2
Hands-On Team
100+
Projects
99%
Planning Approval Success Rate
10+
Years in Practice
What our clients say
Every extension starts with a conversation and ends with a home that works better than before. Here's what clients across South West London say about designing and building with us.
"We'd lived with a dark, cramped kitchen for years. Design United Studio turned it into the room we actually wanted, and handled the planning permission without a single hitch."
"Jürgen understood exactly what we needed from our side return extension before we'd even finished explaining it. The finished space feels like it was always part of the house."
"Professional from the first meeting to the final snag list. Our two storey extension came in on the timeline they gave us, which we didn't expect after hearing other people's horror stories."
SARAH M.
DARWIN P.
Priya K.
Straight answers before you call
Frequently asked questions
Answers to the questions we hear most from homeowners planning a house extension, covering planning permission, cost, and timelines.
