Double-storey extensions in Lincolnshire
Our design and build teams take on double-storey extensions in Lincolnshire, from the first measured survey through planning and building control to the finished room.
- Guide priceFrom £36,000 inc VAT
- PlanningUsually a householder application
- Towns covered10
- Site visitFree, no obligation

Towns in Lincolnshire
Planning and approvals in Lincolnshire
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
What is included
- Measured survey, design and planning drawings
- Ground and first floor structure, roof tied into the existing roof
- Breaking through at both levels, stairs and landing changes where needed
- Householder planning application where needed
- Insulation, plastering, electrics and plumbing to finish
- Building regulations drawings and structural design
The roof is what makes a two-storey extension look right or wrong. We match the pitch and materials of the main house wherever possible and plan the upstairs layout around the existing landing so the new rooms feel original rather than bolted on.
Extensions in and around Lincolnshire
Towns we cover in Lincolnshire include Lincoln, Grimsby, Scunthorpe, Boston, Grantham, Cleethorpes, Spalding, Skegness. 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.
Guide prices for Lincolnshire
Labour and material costs vary across the UK, so for Lincolnshire we use our East Midlands factor (×0.95). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Lincolnshire: £1,470 to £2,850 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m, two floors 24 m² | £36,000 – £43,500 | £41,000 – £54,000 | £52,000 – £68,500 |
| 4 m × 4 m, two floors 32 m² | £47,000 – £56,500 | £54,500 – £71,500 | £69,500 – £91,500 |
| 4 m × 6 m, two floors 48 m² | £70,500 – £84,500 | £82,000 – £107,500 | £104,500 – £137,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
What happens next
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 Lincolnshire home, measure up, talk through what you want and check the planning position.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
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
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Common questions in Lincolnshire
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Lincolnshire, 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 double-storey extension take to build in Lincolnshire?
On site, typically 16 to 24 weeks once approvals are in place. Before that, allow 8–16 weeks design and approvals.
Do I need building regulations approval in Lincolnshire?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Does a double-storey extension need planning permission?
Often, yes. In England a two-storey rear extension can be permitted development only if it projects no more than 3 m and sits at least 7 m from the rear boundary, with matching roof pitch and obscure side windows. Side extensions over one storey always need planning permission. We confirm the route at the survey.
Is a two-storey extension cheaper per square metre?
Usually. Our guide range is about £1,470 to £2,850 per m² of new floor area including VAT, compared with £1,660 to £3,230 per m² for single-storey work, because the foundations and roof are shared across two floors.
Book a free site visit in Lincolnshire
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.