Side return extensions across Grimsby
Grimsby homeowners can use us for the whole side return extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in GrimsbyFrom £17,000 inc VAT
- PlanningOften permitted development; party wall notice usual
- Build time10–14 weeks on site
- Postcode districtsDN31, DN32, DN33, DN34, DN35

Covering Grimsby
Our survey diary covers Grimsby, including DN31, DN32, DN33, DN34, DN35, DN37. Nearby, we also take on projects in Cleethorpes (2 miles), Scunthorpe (24 miles), Lincoln (30 miles), Gainsborough (31 miles).
Just over the East Riding of Yorkshire border, Hull is about 16 miles away. Homes across the East Midlands often have usable side land or a driveway beside the house, which opens up side and wraparound options.
Side return extension prices in Grimsby
These guide figures apply our East Midlands 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 Grimsby: £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 |
Want a range for your exact size? The guide-price tool takes about a minute.
What we take care of
- Survey of the outrigger, boundary wall and drainage
- Party wall notice support (England and Wales)
- Kitchen-ready shell or full finish
- Removal of the side wall and new steelwork
Planning and approvals in Grimsby
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 Grimsby 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.
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).
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
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
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Side return extension questions answered
Will my neighbours in Grimsby 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 see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Grimsby, 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 a side return extension take to build in Grimsby?
On site, typically 10 to 14 weeks once approvals are in place. Before that, allow 6–12 weeks design and approvals.
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 Grimsby, more in London.
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 Grimsby
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.