Side return extensions across Whitehaven
From the first sketch to final sign-off, we plan and build side return extensions in Whitehaven and the surrounding Cumbria area.
- Guide price in WhitehavenFrom £17,000 inc VAT
- PlanningOften permitted development; party wall notice usual
- Build time10–14 weeks on site
- Postcode districtsCA28

Is a side return extension right for your house?
- Victorian and Edwardian terraces with a rear outrigger
- Narrow galley kitchens
- Homes where the garden is too small to lose much depth
Light is the design problem. A side return can make the middle of the house darker if the roof is solid, so we model the daylight and usually recommend a glazed slope or a run of rooflights along the boundary edge.
Do I need planning permission in Whitehaven?
In England a single-storey side return infill is often permitted development if it stays within the height limits and is no wider than half the width of the original house. Conservation areas, listed buildings and flats always need an application, and the boundary wall usually brings in the Party Wall Act.
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.
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.
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 Whitehaven
Across CA28, we can visit, measure and advise. We also work in nearby Workington (7 miles), Ulverston (31 miles), Penrith (33 miles), Barrow-in-Furness (34 miles).
Morecambe, in Lancashire, is roughly 44 miles from Whitehaven and also on our list. Across the North West, terraced houses with small rear yards suit compact rear and side return extensions, while suburban semis have room for more.
What should I budget for a side return extension in Whitehaven?
These guide figures apply our North West England adjustment (×0.95) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Whitehaven: £2,000 to £3,610 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 1.8 m × 4.5 m 8 m² | £17,000 – £20,500 | £18,000 – £23,000 | £22,500 – £29,000 |
| 2 m × 5.5 m 11 m² | £21,500 – £26,500 | £25,000 – £31,500 | £31,000 – £40,000 |
| 2.2 m × 7 m 15 m² | £29,500 – £36,000 | £34,000 – £43,000 | £42,500 – £54,500 |
Try the guide-price tool to see a range for your own size and finish.
Our process, step by step
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
We visit your Whitehaven home, measure up, talk through what you want and check the planning position.
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
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in Whitehaven
Do I need building regulations approval in Whitehaven?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Do you cover all of Whitehaven?
Yes. We cover Whitehaven and the surrounding parts of Cumbria. Site visits are free and there is no obligation.
Who do I contract with for a side return extension in Whitehaven?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Can I combine a side return with a rear extension?
Yes. That combination is a wraparound extension, which adds the most space to a terraced house.
How much does a side return extension cost?
Our guide range is about £2,000 to £3,610 per m² including VAT, so a typical 2 m × 5.5 m infill lands around £25,000 to £31,500 at standard spec in Whitehaven, more in London.
Book a free site visit in Whitehaven
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.