Bromley · South East London · North West Kent
Extension plans, without the guesswork.
Fixed-fee planning and building regulations drawings for homeowners — with the measured survey included and a clear price before you commit.
Survey, design call and drawings in one package
Submitted to your council for you
Party wall help from a chartered surveyor
Get your fixed-fee quote
Step 1 of 3 · Takes about 2 minutes
No obligation. We never share your details.
Fixed fee
Know the cost upfront
Quote in 1 day
Fast, clear pricing
Measured survey
Laser scanned and accurate
Truly local
Bromley and SE London
How Extension Plan works · 2 min
Who we are
One local team. One fixed fee.
We do one thing well: planning and building regulations drawings for homeowners extending their homes, with party wall help when you need it.
Who is behind Extension Plan?
Run by a practising chartered surveyor in Bromley, so you get practical advice on what is buildable.
Why do you only do drawings?
Because that is where we add most value: a clear, accurate, council-ready drawing set for a fixed fee. You choose your own builder and stay in control.
How are you different from a local architect?
The fee is fixed up front, the survey is included and design calls happen on video, so price and timeline are clear before you commit.
How it works
From first idea to builder-ready, in four steps
Everything happens online, on your schedule. You will have a fixed price before you commit and a named person to talk to throughout.
STEP 1
Get a fixed quote
Choose your package and tell us about the work. You get a clear price straight away.
STEP 2
We measure your home
A laser survey records every room, wall and level so the drawings start accurate.
STEP 3
Design together on video
Talk through your ideas on a video call and agree the layout before drawings begin.
STEP 4
We draw and submit
We prepare and submit your householder planning application and building regulations pack.
What you get
Clear packages, no surprises
Pick the package that fits your project. Every one starts with a measured survey and a design call.
Fixed, upfront fee
One price agreed before we start, with no hourly billing.
Measured survey
Accurate drawings of your existing home from a laser survey of every room.
Video design call
Talk through your ideas with us before drawings begin.
Planning submission
We prepare and submit your householder planning application.
Building regulations pack
Detailed drawings for building control and your engineer, coordinated with the design.
Party wall support
Notices and awards handled by a chartered surveyor when you need them.
Why drawings-only
Pay for the drawings, not the overhead.
A traditional practice covers a wide range of services. We focus on one job for homeowners, so the price is fixed, the process is repeatable and what you pay for is clear.
| Compared | Extension Plan | Traditional practice |
|---|---|---|
| How you pay | Fixed fee from £1,950 | Hourly, or 3–12% of build cost |
| Measured survey | Included in every package | Usually an extra cost |
| Design meetings | Video calls, on your schedule | Often in person, in office hours |
| Scope | Planning and building regulations drawings | Full design and site service |
| Best for | Homeowners extending their home | Larger or more complex projects |
“Homeowners shouldn’t need to be experts to get an extension off the ground. Our job is to make the plans clear and the price certain.”
Founder, Extension Plan
Chartered surveyor · Draft quote — replace with your own words
Chartered surveyor-led
Practical advice on what can actually be built, drawn from real surveying experience.
Local knowledge
We work in Bromley, South East London and North West Kent, so we know the councils and the housing.
Not sure where to start?
Book a free 15-minute call
Talk through your idea before any survey is booked. We check feasibility, planning risks and budget, then recommend the right package.
Project example
See what your drawings will look like
Placeholder: replace these tiles with one of your own projects, from existing plans to the finished extension.
As found
Measured survey
Proposed drawings
Finished extension
FAQ
Questions homeowners ask us
Cannot see your question? Call or email and we will help.
How much does it cost?
Packages are fixed fees shown before you commit, from £1,950. Council planning and building control fees are paid separately.
How long does it take?
Timelines depend on the package and your schedule; we confirm them on the discovery call.
Do you submit the application?
Yes. We prepare and submit your householder planning application.
Will I need a party wall agreement?
Possibly, if work is on or near a boundary or near a neighbour’s building. We advise on the call.
Which areas do you cover?
Bromley, South East London and North West Kent, including Bexley, Greenwich, Lewisham, Dartford and Croydon.
Ready for a fixed price?
Tell us about your project and get a clear fixed-fee quote within 1 working day.
Get a fixed quote