Side return extensions in Portsmouth
Thinking about a side return extension for your Portsmouth home? Start with a free site visit: we measure up, check what the council will allow and give you honest guide figures on the day.
- Guide price in PortsmouthFrom £20,000 inc VAT
- PlanningOften permitted development; party wall notice usual
- Build time10–14 weeks on site
- Postcode districtsPO1, PO2, PO3, PO4, PO5

Local to Portsmouth
We cover Portsmouth and the postcode districts PO1, PO2, PO3, PO4, PO5, PO12. Nearby, we also take on projects in Gosport (2 miles), Fareham (5 miles), Havant (6 miles), Waterlooville (6 miles).
Homes across the South East range from Victorian terraces in the older town centres to large detached houses on the edges, so the right extension type varies street by street.
What should I budget for a side return extension in Portsmouth?
These guide figures apply our South East England adjustment (×1.12) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Portsmouth: £2,350 to £4,260 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 1.8 m × 4.5 m 8 m² | £20,000 – £24,000 | £21,500 – £27,000 | £26,500 – £34,500 |
| 2 m × 5.5 m 11 m² | £25,500 – £31,000 | £29,500 – £37,000 | £36,500 – £47,000 |
| 2.2 m × 7 m 15 m² | £35,000 – £42,500 | £40,000 – £50,500 | £50,000 – £64,000 |
For a figure based on your own dimensions, use our guide-price tool.
Planning and approvals in Portsmouth
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.
The planning position for a specific Portsmouth address depends on its history and any designations, which is why we check it at the first visit.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
Who a side return extension suits
- Narrow galley kitchens
- Homes where the garden is too small to lose much depth
- Victorian and Edwardian terraces with a rear outrigger
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.
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Portsmouth
How long does a side return extension take to build in Portsmouth?
On site, typically 10 to 14 weeks once approvals are in place. Before that, allow 6–12 weeks design and approvals.
Do you cover all of Portsmouth?
Yes. We cover Portsmouth and the surrounding parts of Hampshire. Site visits are free and there is no obligation.
Will my neighbours in Portsmouth 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.
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.
Do side return extensions need planning permission?
In England many single-storey side returns fit within permitted development if they stay within the height limits and are no wider than half the width of the original house. Conservation areas, listed buildings and flats need an application. Other UK nations have their own rules, which we check.
Book a free site visit in Portsmouth
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.