House extensions
Rear, side-return and wraparound extensions that add real space — designed with your borough's planning appetite in mind.
London architectural design studio
More space, less stress — designed to be approved
Extensions, loft conversions and everything in between — measured, designed and steered through planning and building control by one London studio, at a fixed fee.
Takes about 60 seconds. No obligation, no spam — see our privacy notice.
- Fixed fees, agreed up front
- Planning-led design across London
- One studio from survey to building control
- Fully insured & ICO registered
What we do
Every drawing your project needs, under one roof
From the first measured survey to the final building control package — no hand-offs between firms, no gaps in responsibility.
Loft conversions
Dormer, hip-to-gable and mansard lofts. We check headroom, stairs and fire strategy before you commit a penny to building.
Outbuildings & garden rooms
Studios, offices and annexes — often achievable under permitted development, and we'll tell you straight away if yours is.
Flat conversions
Converting houses into flats, or reconfiguring existing ones — layouts, space standards and planning strategy handled together.
Planning permission
Full applications, householder applications and lawful development certificates — prepared, submitted and managed for you.
Building control packages
Technical drawings and specifications your builder can price and build from, coordinated with structural calculations.
Lease plans
Land Registry compliant lease plans for sales, new leases and lease extensions — drawn accurately and turned around fast.
Measured surveys
Precise measured surveys of your property — the accurate base every good design, planning drawing and lease plan starts from.
How it works
From first call to approved drawings
A clear, fixed-fee process — you'll always know what happens next and what it costs.
Quote & consultation
Tell us about your property and plans. You'll get a fixed-fee quote and a free call to talk through feasibility and planning risk.
Measured survey
We visit once to survey your property accurately, then produce existing drawings everything else builds on.
Design & planning
We develop the design with you, then prepare and submit your planning or permitted development application and manage it to decision.
Building control package
Technical drawings, specifications and structural coordination — everything your builder needs to price accurately and build safely.
Quick quote
Get your fixed-fee quote in 60 seconds
Four short questions — no account needed, and we only ask for what we need to price your project.
Speak to an expert
Not sure where to start? Let's talk it through.
Book a free 30-minute call with our design team. No hard sell — just honest answers about what's possible on your property.
- Whether your project needs planning permission, or could fall under permitted development
- What similar projects in your borough have been approved recently
- Realistic timelines and what your design fees will be — fixed, in writing
Prefer to reach out directly? Email info@dsdesignlondon.co.uk.
Good to know
Questions we hear a lot
Do I need planning permission for my extension or loft?
Not always — many rear extensions, lofts and outbuildings fall under permitted development rights, which is usually quicker and cheaper. It depends on your property type, its history and whether you're in a conservation area. We check this for every project and tell you honestly which route we'd recommend.
How much do architectural drawings cost?
Every quote is fixed and itemised, so you can see exactly what the survey, design, planning and building control stages cost — and choose how far you want to take things with us. Use the quick quote above and we'll email you a tailored figure, usually within one working day.
Do you cover my area?
We work across all London boroughs and the surrounding areas. Lease plans and some survey work can be arranged further afield — just ask.
What happens to my data when I fill in a form?
Your details are used only to answer your enquiry and prepare your quote. We're registered with the ICO, we don't sell or share your data for marketing, and if you don't become a client we delete your enquiry details within 12 months. You can ask us to delete them sooner at any time — the full details are in our privacy notice.
Can you take over a project another designer started?
Yes — we regularly pick up projects mid-way, whether that's redrawing for planning after a refusal or producing the building control package from someone else's approved design. Send us what you have and we'll quote for the remaining stages.