What is a single-storey extension?

A single-storey extension is a ground-floor addition, usually at the rear of a house, that enlarges a kitchen, living or dining space. Most are built with cavity walls on concrete foundations and finished with a flat roof and roof lantern or a pitched tiled roof.
How much does a single-storey extension cost in Cleethorpes?
In Cleethorpes, a single-storey extension typically costs £1,850–£2,750 per m² of floor area, including VAT at 20% (standard rate). For a typical 20 m² project that is roughly £37,000–£55,000. That range is adjusted for the East Midlands, where domestic building work typically costs around 5% below the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (14 m²) | £26,000–£38,500 |
| Typical project (20 m²) | £37,000–£55,000 |
| Larger project (28 m²) | £52,000–£77,000 |
| Rate per m² | £1,850–£2,750 |
Your quote will depend mainly on:
- Kitchen, flooring and finishes, which we can include or leave to you
- Floor area and the length of new wall
- Glazing: sliding and bifold doors cost more than French doors
- Roof type and the size of any lantern or roof windows
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a single-storey extension in Cleethorpes?
Whether you need planning permission depends on your house and its location in England. In England a single-storey rear extension is often permitted development: broadly up to 3 metres deep on a semi-detached or terraced house and 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres within 2 metres of a boundary, and covering no more than half the garden. The larger home extension scheme allows up to 6 or 8 metres if you notify the council first and neighbours have a chance to comment. In conservation areas, National Parks and National Landscapes the larger home extension route, side extensions and cladding are not permitted development. Flats and houses whose rights have been removed need a planning application, and listed buildings need listed building consent.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
We check this for your address before design work starts, so there are no surprises later.
What we handle
From survey to sign-off, the job normally involves:
- Doors, windows and roof glazing installed
- Building control inspections and completion certificate
- Foundations, drainage and any build-over agreement
- Measured survey and design drawings
- Cavity walls, insulation and roof to current building regulations
- Structural calculations for steels and lintels
How long does it take?
The build itself usually takes 10 to 14 weeks on site for a typical rear extension, after approvals. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Cleethorpes
In the East Midlands, many estates built since the 1960s have integral garages that convert well into a study or bedroom.
Our Cleethorpes coverage includes postcode districts DN35, and we also work in nearby places such as Grimsby, Hull and Brough.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about single-storey extensions in Cleethorpes
What is a build-over agreement?
If a public sewer runs within 3 metres of the extension, the water company normally has to agree to the work before it starts. We check sewer records during design and apply where needed.
Do you build single-storey extensions in Cleethorpes?
Yes. We build single-storey extensions across Cleethorpes, including postcodes DN35. Every project starts with a free home visit.
How much does a single-storey extension cost in Cleethorpes?
In Cleethorpes, a single-storey extension typically costs £1,850–£2,750 per m² of floor area, including VAT at 20% (standard rate). A typical 20 m² project comes to roughly £37,000–£55,000. Your fixed price depends on the survey and drawings.
Is VAT charged on an extension?
Yes. Building work on an existing home is standard-rated, so VAT at 20% applies. Our guide prices include it.
Do I need planning permission for a single-storey extension?
Not always. Many small rear extensions are permitted development, within limits on depth, height and how much of the garden is covered. The limits depend on which nation you live in and on protected areas such as conservation areas, and flats or houses whose rights have been removed need an application. We check this at the survey and can apply to the council for formal confirmation.
