Conservatory replacement extensions across Gainsborough
Planning a conservatory replacement in Gainsborough? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide price in GainsboroughFrom £19,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–14 weeks on site
- Postcode districtsDN21

Will the council need to approve it?
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
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.
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.
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).
Conservatory replacement prices in Gainsborough
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 Gainsborough: £1,760 to £3,320 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 3.3 m 10 m² | £19,000 – £23,000 | £20,000 – £26,500 | £26,000 – £33,500 |
| 3.5 m × 4 m 14 m² | £24,500 – £29,500 | £28,500 – £37,000 | £36,500 – £47,000 |
| 4 m × 5 m 20 m² | £35,000 – £42,000 | £40,500 – £52,500 | £52,000 – £66,500 |
Includes removal of the old conservatory. Reusing existing foundations is only possible after investigation.
For a figure based on your own dimensions, use our guide-price tool.
What is included
- New or upgraded foundations
- Trial holes to check the existing foundations
- Glazing and doors to suit the new room
- Insulated walls and roof to current regulations
- Removal and disposal of the old conservatory
Extensions in and around Gainsborough
Site visits are available across Gainsborough (DN21). We also work in nearby Scunthorpe (14 miles), Lincoln (14 miles), Grimsby (31 miles), Cleethorpes (33 miles).
Retford, in Nottinghamshire, is roughly 8 miles from Gainsborough and also on our list. The East Midlands has plenty of inter-war and post-war semis and detached houses with room to extend, alongside Victorian terraces in the towns.
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions people ask about conservatory replacements
Do you cover all of Gainsborough?
Yes. We cover Gainsborough and the surrounding parts of Lincolnshire. Site visits are free and there is no obligation.
Do I need building regulations approval in Gainsborough?
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 Gainsborough, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Is it worth replacing a conservatory with an extension?
If the conservatory is unusable for much of the year, usually yes. A solid extension gives a heated room that counts as proper living space. Our guide range is about £1,760 to £3,320 per m² including VAT, including removal.
Does replacing a conservatory need planning permission?
A solid replacement is treated as a new extension, so it must meet the permitted development limits or get planning permission, and it always needs building regulations approval.
Book a free site visit in Gainsborough
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.