Extension plans and drawings across Marlow
For Marlow homeowners we handle extension plans and drawings, with fees agreed in writing before any work starts.
- Guide price in MarlowFrom £1,300 inc VAT
- PlanningWe find the right route for you
- Timescale2–6 weeks for drawings
- Postcode districtsSL7
Planning rules that apply in Marlow
In England the main routes are permitted development (ideally confirmed with a lawful development certificate, £274), larger home extension prior approval (£249, 42 days) and a householder planning application (£548, normally 8 weeks), with council fees as set from 1 April 2026.
The planning position for a specific Marlow address depends on its history and any designations, which is why we check it at the first visit.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Who this service is for
- Projects that need a planning application or other approval
- Homeowners at the very start of a project
- Anyone who wants fixed designs before getting build prices
Local to Marlow
We cover Marlow and the postcode districts SL7. Nearby, we also take on projects in High Wycombe (4 miles), Gerrards Cross (9 miles), Amersham (10 miles), Chalfont St Peter (10 miles).
For homes towards Berkshire, Maidenhead is around 4 miles away. In the South East, plenty of houses have already been extended once, which makes checking the remaining permitted development allowance an important early step.
Design and approval fees for Marlow
Fees below are our Marlow guide (×1.12, the South East England factor), including VAT. Council and building control fees are extra.
| Option | What it covers | Guide price |
|---|---|---|
| Essential | Measured survey and planning drawings | £1,300 – £2,500 |
| Standard | Planning drawings plus building regulations drawings | £2,450 – £4,300 |
| Premium | Full pack with structural calculations and 3D visuals | £3,800 – £6,200 |
Want a range for your exact size? The guide-price tool takes about a minute.
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Marlow home, measure up, talk through what you want and check the planning position.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in Marlow
Will my neighbours in Marlow be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
How long does this take for a Marlow home?
2–6 weeks for drawings, depending on the council and the complexity of the project.
Do you cover all of Marlow?
Yes. We cover Marlow and the surrounding parts of Buckinghamshire. Site visits are free and there is no obligation.
How much do extension plans cost?
Our design packs range from about £1,300 to £6,200 including VAT, from planning drawings only to a full pack with building regulations drawings, structural calculations and 3D views. Council fees are separate.
Do I need an architect?
Not necessarily. For most extensions an experienced designer or architectural technologist is enough. For listed buildings or complex sites an architect’s input can help.
Book a free site visit in Marlow
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.