Two-storey extensions for semi-detached houses in Maryport

Maryport: the key facts for this kind of project.

Postcode districts: CA15
County / area: Cumbria, England
Price region: North West England
Guide price: £53,000–£72,000 (£1,900–£2,560 per m²)
Approval route: Depends on position: a two-storey rear extension may be permitted development (3 m deep, 7 m from the rear boundary); a two-storey side extension needs planning permission.
Nearest towns: Workington (5.3 miles), Cockermouth (6.5 miles), Whitehaven (12 miles)
Distance to Carlisle: about 25.5 miles
First visit: Free, no obligation

About a two-storey extension for a semi-detached house

This service suits you if you own a semi-detached house and want to add bedrooms and living space without moving. On a semi, the main questions are which side to build on and how to treat the attached neighbour. You get a survey, design options, the approvals your nation needs and the build, carried out by vetted teams working under S&K.

Maryport sits about 25.5 miles from Carlisle. Closer to home, Workington is 5.3 miles away and Cockermouth 6.5 miles.

What it costs in Maryport

In North West England, which includes Maryport, we'd expect a two-storey extension for a semi-detached house to cost around £53,000–£72,000 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), or £1,900–£2,560 per m² including VAT. Professional fees for drawings and the structural engineer are listed separately on our prices page.

Spec	Per m²	A 4 m × 3.5 m footprint on two floors (28 m² of new floor space)
Essential	£1,750–£2,360 per m²	£49,000–£66,000
Standard	£1,900–£2,560 per m²	£53,000–£72,000
Premium	£2,280–£3,080 per m²	£64,000–£86,000

Planning and building regulations in Maryport

In England, a two-storey rear extension on a semi can be permitted development if it goes no more than 3 m beyond the original rear wall and stays 7 m from the rear boundary, with matching materials and roof pitch. A two-storey side or wraparound extension always needs planning permission, costing £548 (or £575 for applications made from 8 December 2026). Protected areas such as conservation areas exclude two-storey rear permitted development.

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 Maryport homes

Keeping the pair balanced

Semis are designed as matching pairs, and a side extension changes that balance. Setting the side extension back from the front wall and keeping its ridge lower helps the pair still read as a pair, which councils' design guides commonly ask for.

Rear, side or both

On a semi, a rear extension sits against the attached neighbour, while a side extension faces the detached neighbour and the street. We compare the space, cost and approval route for each, and for a wraparound, before you commit to one design.

How we'd run your project

Start at your house
We come to your home in Maryport, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Get it approved
Once you're happy with the design we submit it to the council for Maryport and deal with any questions from the planning officer.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about two-storey extensions for semi-detached houses in Maryport

Who handles building regulations for a project in Maryport?

We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

Do I need planning permission for a two-storey extension for a semi-detached house in Maryport?

Maryport is in England, so England planning rules apply. Depends on position: a two-storey rear extension may be permitted development (3 m deep, 7 m from the rear boundary); a two-storey side extension needs planning permission. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

Which postcodes do you cover around Maryport?

We cover Maryport (CA15) and nearby places including Workington, Cockermouth and Whitehaven, plus the rest of Cumbria. The first site visit is free.

What if my neighbour has already extended?

That often helps. An existing extension next door can reduce the effect of yours on their light, and may show what the council accepts on your street. It can also mean building alongside their wall, so we check its position, foundations and any windows facing your plot at the survey.

Will a side extension make my semi look like a terrace?

It can if it fills the whole gap to the boundary at first floor and the neighbour does the same. Many councils ask for a first-floor gap to the side boundary or a set-back for this reason. We design the extension to keep the semi reading as one of a pair.

Nearby

Close to Maryport? We work across the area, including:

Other extensions in Maryport

All two-storey extension services in Maryport · Two-storey extensions for semi-detached houses across Cumbria

Want a figure first? Try our guide price tool, then book a free visit to firm it up.