Extension plans and drawings in Henley-on-Thames
Need extension plans and drawings in Henley-on-Thames? We survey the house, prepare what the council needs and deal with the officers until a decision is made.
- Guide price in Henley-on-ThamesFrom £1,300 inc VAT
- PlanningWe find the right route for you
- Timescale2–6 weeks for drawings
- Postcode districtsRG9
What we take care of
- Building regulations drawings and specification
- Structural calculations from an engineer (full pack)
- Measured survey of the house and garden
- Planning drawings: existing and proposed plans and elevations, site and location plans
- 3D views to check the look and the light (full pack)
- Two or three layout options to compare
The most expensive changes are the ones made after the steel is ordered. A good design stage settles layout, heights, glazing and services on paper, so the build price is firm.
Will the council need to approve it?
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 Henley-on-Thames 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.
Applications are decided by the local planning authority (your district, borough or unitary council).
Extensions in and around Henley-on-Thames
Postcode districts we cover around Henley-on-Thames include RG9. Neighbouring towns we cover include Thame (14 miles), Didcot (14 miles), Abingdon (18 miles), Oxford (20 miles).
Reading, in Berkshire, is roughly 6 miles from Henley-on-Thames and also on our list. Homes across the South East range from Victorian terraces in the older town centres to large detached houses on the edges, so the right extension type varies street by street.
Fees in Henley-on-Thames
These are guide fees for Henley-on-Thames, adjusted for South East England (×1.12) and including VAT. Council application and inspection fees are paid separately.
| 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 |
For a figure based on your own dimensions, use our guide-price tool.
What happens next
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions answered
How long does this take for a Henley-on-Thames home?
2–6 weeks for drawings, depending on the council and the complexity of the project.
Do I need building regulations approval in Henley-on-Thames?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Do you cover all of Henley-on-Thames?
Yes. We cover Henley-on-Thames and the surrounding parts of Oxfordshire. 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 Henley-on-Thames
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.