Annexe extensions across Harwich
From the first sketch to final sign-off, we plan and build annexe extensions in Harwich and the surrounding Essex area.
- Guide price in HarwichFrom £58,000 inc VAT
- PlanningUsually a householder application
- Build time16–24 weeks on site
- Postcode districtsCO12
Extensions in and around Harwich
Site visits are available across Harwich (CO12). Nearby, we also take on projects in Clacton-on-Sea (12 miles), Colchester (17 miles), Witham (29 miles), Maldon (30 miles).
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.
Planning and approvals in Harwich
In England an annexe that stays part of the household and connects to the house is assessed as an extension, but its size usually takes it beyond permitted development, so a householder application describing the ancillary use is the normal route.
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).
Annexe extension prices in Harwich
Labour and material costs vary across the UK, so for Harwich we use our East of England factor (×1.06). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Harwich: £2,120 to £4,030 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Studio annexe 25 m² | £58,000 – £73,000 | £63,500 – £79,500 | £79,500 – £101,000 |
| One-bedroom annexe 35 m² | £74,000 – £93,000 | £89,000 – £111,500 | £111,000 – £141,000 |
| Larger annexe 45 m² | £95,000 – £119,500 | £114,000 – £143,500 | £143,000 – £181,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Is an annexe extension right for your house?
- Multi-generational families
- Homes with a large side or rear garden
- Relatives who need support close by
How the project works
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
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in Harwich
Do I need building regulations approval in Harwich?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Harwich, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How long does an annexe extension take to build in Harwich?
On site, typically 16 to 24 weeks once approvals are in place. Before that, allow 10–16 weeks design and approvals.
Can the annexe have its own front door?
Yes, many do, but it should still connect to the main house to stay clearly part of it.
How much does an annexe extension cost?
Our guide range is about £2,120 to £4,030 per m² including VAT. A one-bedroom annexe of about 35 m² is typically £89,000 to £111,500 at standard spec in Harwich.
Book a free site visit in Harwich
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.