Two-storey side extensions in Mablethorpe
We cover Mablethorpe and the rest of Lincolnshire for two-storey side extensions. Start with a free site visit and a plain-English view of what your house and plot can take.
Quick reference for homeowners in Mablethorpe.
- Postcode districts
- LN12 and LN13
- County / area
- Lincolnshire, England
- Price region
- East Midlands
- Guide price
- £84,500–£113,000 (£2,010–£2,700 per m²)
- Approval route
- Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
- Nearest towns
- Louth (11.1 miles), Skegness (14 miles), Cleethorpes (19.4 miles)
- Distance to Lincoln
- about 33.9 miles
- First visit
- Free, no obligation
About a two-storey side extension
A two-storey side extension is a new two-floor addition built into the space beside your house, often over a driveway or side passage. It typically adds one or two bedrooms upstairs and a utility, study or larger kitchen below, without giving up rear garden.
Around Mablethorpe we also work in Louth, Skegness and Cleethorpes, and across the rest of Lincolnshire. Postcode districts in and near Mablethorpe: LN12 and LN13.
What it costs in Mablethorpe
Expect a two-storey side extension in Mablethorpe to land somewhere around £84,500–£113,000 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). Our East Midlands guide rate is £2,010–£2,700 per m², including VAT. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.
| Spec | Per m² | A 3 m × 7 m footprint on two floors (42 m² of new floor space) |
|---|---|---|
| Essential | £1,850–£2,480 per m² | £77,500–£104,000 |
| Standard | £2,010–£2,700 per m² | £84,500–£113,000 |
| Premium | £2,410–£3,230 per m² | £101,500–£136,000 |
Planning and building regulations in Mablethorpe
In England, a two-storey side extension always needs householder planning permission, because permitted development only allows single-storey extensions beyond a side wall. The fee is £548 (or £575 for applications made from 8 December 2026), and councils should decide within 8 weeks of validation. Expect them to look at set-back, roof height, gaps to the boundary and the effect on neighbours.
Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.
Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.
Design points for Mablethorpe homes
Side windows, boundaries and gutters
Upstairs windows in the side wall face the neighbour, so they are usually obscure-glazed and fixed, or left out. Building close to the boundary also raises questions about foundations, overhanging gutters and access for maintenance, so we design the eaves and gutter to stay within your land.
Set-down and set-back
Councils usually want a two-storey side extension to look subordinate to the house. Setting the front wall back from the main front and dropping the ridge slightly below the main roof helps it read as an addition, and is often expected in local design guidance.
How we'd run your project
Look at the house
We start in Mablethorpe with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Design and approvals
We draw the extension and check it against the rules for England, then apply for planning permission or a certificate of lawfulness, whichever fits.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.
Questions about two-storey side extensions in Mablethorpe
How much does a two-storey side extension cost in Mablethorpe?
Our guide for the East Midlands, which covers Mablethorpe, is £2,010–£2,700 per m² including VAT. A typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £84,500–£113,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
How long does a two-storey side extension take?
Allow 4 to 8 weeks for survey and design, then the approval period (councils should decide householder applications within 8 weeks of validation), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.
Do I need planning permission for a two-storey side extension in Mablethorpe?
Mablethorpe is in England, so England planning rules apply. Planning permission is needed: in England, permitted development only allows single-storey extensions to the side. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.
Which postcodes do you cover around Mablethorpe?
We cover Mablethorpe (LN12 and LN13) and nearby places including Louth, Skegness and Cleethorpes, plus the rest of Lincolnshire. The first site visit is free.
Can I build a two-storey side extension over my driveway?
Yes, if the drive is wide enough for a useful room and the council accepts the design. You may lose off-road parking, which some councils weigh up, and the foundations need to suit the ground below. We check parking, drains and meter positions at the free site visit before any drawings are prepared.
Nearby
Nearby towns we cover for two-storey side extensions:
Other extensions in Mablethorpe
- Rear
- Wraparound
- Part two-storey
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Mablethorpe · Two-storey side extensions across Lincolnshire
Tell us about your house in Mablethorpe and we'll call you back to arrange a free, no-obligation visit.