Single-storey extensions · Cowes

Single-storey extensions in Cowes

We take on single-storey extensions in Cowes as a complete project: survey, drawings, planning or permitted development checks, building control and the construction itself.

Covering Cowes

Cowes is about 4 miles north of Newport. We also cover Newport (4 miles to the south), Ryde and Gosport.

Because the Isle of Wight covers a wide area, we confirm availability after the first call and include any travel costs in the written quote rather than adding them later.

Homes in the South East

Many South East homes are inter-war or post-war semis and detached houses with room for rear and side extensions, while historic town centres and villages bring conservation area and listed building controls.

What goes into a single-storey extension?

We design the extension around how you use the house: where the light comes from, how the new room joins the old one, and what happens to the drains and the garden. The structure is built in brick or block to match the house, finished with a flat roof and lantern or a pitched roof, then insulated, plastered and handed back ready to decorate.

  • Planning or lawful development certificate where needed
  • Building control application and inspections
  • First-fix and second-fix electrics, plastering and making good

How much does a single-storey extension cost in Cowes?

Indicative costs for single-storey extensions. London and the South East usually sit towards the top of each range.

Single-storey extensionsGuide price incl. VAT
Standard specification£2,600 to £3,000 per m²
Good specification£3,000 to £3,500 per m²
High specification£3,500 to £4,000 per m²

Do you need permission for a single-storey extension in Cowes?

Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 applies.

In England a single-storey rear extension can often go ahead under permitted development: up to 3 m deep on an attached house or 4 m on a detached one, no higher than 4 m, with eaves no higher than 3 m within 2 m of a boundary. Deeper extensions, up to 6 m or 8 m, need prior approval from the council first.

What can change the price or programme?

  • Drains under the footprint may need diverting or a build-over agreement with the water company.
  • Kitchens and doors have long lead times, so we order them early.

What are the steps?

  1. Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
  2. Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
  3. Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
  4. Construction and completion. One site lead co-ordinates every trade through to the building control certificate.

Questions about a single-storey extension in Cowes

How much does a single-storey extension cost?

Most single-storey extensions cost about £2,600 to £4,000 per square metre including VAT, depending on specification, glazing and ground conditions. We give a fixed price in writing for the agreed specification after the survey.

Do you need to dig up the drains?

Sometimes. If a public sewer runs under the extension, the water company has to agree a build-over or a diversion. We check this at survey stage.

Do you work in Cowes?

Yes. Cowes is within our coverage for single-storey extensions, along with nearby Newport and Ryde.

Also covering

Learn more about single-storey extensions, or see every project we cover in Cowes.

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