Extension plans and drawings across Harlow
We prepare extension plans and drawings for homes in Harlow, as a stand-alone service or as the first stage of a design and build project.
- Guide price in HarlowFrom £1,250 inc VAT
- PlanningWe find the right route for you
- Timescale2–6 weeks for drawings
- Postcode districtsCM17, CM18, CM19, CM20

Planning and approvals in Harlow
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.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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
- Building regulations drawings and specification
- 3D views to check the look and the light (full pack)
- Structural calculations from an engineer (full pack)
- Two or three layout options to compare
- Planning drawings: existing and proposed plans and elevations, site and location plans
- Measured survey of the house and garden
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.
Fees in Harlow
These are guide fees for Harlow, adjusted for East of England (×1.06) and including VAT. Council application and inspection fees are paid separately.
| 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 |
Try the guide-price tool to see a range for your own size and finish.
Covering Harlow
Across CM17, CM18, CM19, CM20, we can visit, measure and advise. We also work in nearby Waltham Abbey (8 miles), Brentwood (14 miles), Chelmsford (16 miles), Billericay (17 miles).
Across the East of England many houses sit on generous plots, and single-storey and wraparound extensions are a natural fit.
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
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
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 Harlow home?
2–6 weeks for drawings, depending on the council and the complexity of the project.
Do you cover all of Harlow?
Yes. We cover Harlow and the surrounding parts of Essex. Site visits are free and there is no obligation.
Will my neighbours in Harlow 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.
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.
Can I use your drawings with another builder?
Yes. Once paid for, the drawings are yours to use for your project.
Book a free site visit in Harlow
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.