Harwich, Essex
Rear extension planning drawings in Harwich
Measured survey, design options, planning drawings and the application, handled for you. If you live in Harwich and want to know what a rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Harwich and its postcode districts CO12 are part of our Essex coverage. For Harwich homes we start with a measured survey, then draw options before anything is submitted.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
What do rear extension planning drawings cost in Harwich?
As a guide, £1,000–£2,500 including VAT for a single-storey rear extension, or £2,000–£3,500 for a two-storey scheme. A householder planning application in England costs £548 (£575 for applications made from 8 December 2026), and a lawful development certificate for proposed work costs half the householder fee. Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a rear extension in Harwich?
Whether your rear extension in Harwich needs a planning application depends on its size, your house and any local restrictions.
A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.
Councils aim to decide householder applications within 8 weeks of validation, and prior approval within 42 days.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Harwich like to extend?
Post-war semis and newer estates are typical of Harwich, and many have room for a full-width extension. Shrinkable clay is common in the East of England, so foundations near trees and hedges are designed to NHBC-style depth guidance.
How a rear extension in Harwich comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Rear extension planning drawings near Harwich
We also build rear extensions in nearby Felixstowe (3.2 miles) and Walton-on-the-Naze (6.5 miles).
- Rear extension planning drawings in Felixstowe
- Rear extension planning drawings in Walton-on-the-Naze
- Rear extension planning drawings in Frinton-on-Sea
- Rear extension planning drawings in Kesgrave
- Rear extension planning drawings in Ipswich
Other work in Harwich:
FAQ
Rear extension planning drawings questions in Harwich
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
What postcode areas do you cover around Harwich?
Including CO12, and the surrounding Essex area.
Can planning conditions affect the build?
Yes, for example matching materials or obscure glazing. We plan for them.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
Do you handle building control in Harwich?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Do I need planning permission for a rear extension in Harwich?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.