Extension plans and drawings across Brentwood
Need extension plans and drawings in Brentwood? We survey the house, prepare what the council needs and deal with the officers until a decision is made.
- Guide price in BrentwoodFrom £1,250 inc VAT
- PlanningWe find the right route for you
- Timescale2–6 weeks for drawings
- Postcode districtsCM13, CM14, CM15
Working in Brentwood
Postcode districts we cover around Brentwood include CM13, CM14, CM15. The same team covers Billericay (5 miles), Basildon (7 miles), South Ockendon (8 miles), Stanford-le-Hope (9 miles), all within easy reach.
The East of England mixes market-town terraces, inter-war semis and modern estates. Clay soils are common in parts of the region, which can affect foundation design.
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.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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).
Included in a typical project
- Planning drawings: existing and proposed plans and elevations, site and location plans
- Building regulations drawings and specification
- 3D views to check the look and the light (full pack)
- Measured survey of the house and garden
- Structural calculations from an engineer (full pack)
Fees in Brentwood
Fees below are our Brentwood guide (×1.06, the East of England factor), including VAT. Council and building control fees are extra.
| Option | What it covers | Guide price |
|---|---|---|
| Essential | Measured survey and planning drawings | £1,250 – £2,350 |
| Standard | Planning drawings plus building regulations drawings | £2,300 – £4,050 |
| Premium | Full pack with structural calculations and 3D visuals | £3,600 – £5,850 |
For a figure based on your own dimensions, use our guide-price tool.
From first visit to completion
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
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
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Common questions in Brentwood
How long does this take for a Brentwood home?
2–6 weeks for drawings, depending on the council and the complexity of the project.
Do you cover all of Brentwood?
Yes. We cover Brentwood and the surrounding parts of Essex. Site visits are free and there is no obligation.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Brentwood, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
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.
How much do extension plans cost?
Our design packs range from about £1,250 to £5,850 including VAT, from planning drawings only to a full pack with building regulations drawings, structural calculations and 3D views. Council fees are separate.
Book a free site visit in Brentwood
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.