House Extension Cost Per Square Metre in Exmouth: What to Expect

Typical per square metre figures around Exmouth

For a straightforward single storey extension in Exmouth, most homeowners should budget between £2,200 and £3,300 per square metre for the build itself. That assumes a decent standard of finish, with plastering, electrics, heating and basic flooring included. Higher specification work, such as wide glazed openings, vaulted ceilings or bespoke joinery, can reach £3,500 to £4,000 per square metre or more.

On those figures, a 25 square metre rear kitchen extension would come in at roughly £55,000 to £82,500 before VAT and before the kitchen itself. Two storey extensions usually work out cheaper per square metre, often around £2,000 to £2,900, because the upper floor shares the same foundations and roof. Treat all of these as guide ranges, not quotes. The real number depends on your plot, your design and the finish you choose.

What the per square metre figure usually leaves out

Most headline rates cover construction only. The extras below are where budgets tend to come unstuck, so ask any builder exactly what their figure includes.

As a rule of thumb, allow a further 10 to 15 percent for professional fees and approvals, and keep a contingency of around 10 percent for anything found once the ground is opened up.

• VAT at 20 percent, which applies to most extension work
• Architectural drawings and structural engineer calculations
• Planning application and building control fees
• Kitchen or bathroom fit out, including appliances and worktops
• A build over agreement with South West Water if you are near a public sewer
• Party wall surveyor costs on terraced and semi-detached homes
• Decorating, landscaping and making good the patio or driveway

What drives the price up locally

Two houses on the same Exmouth street can get very different quotes for the same size of extension. The reasons are usually below ground or outside the builder's control.

• Ground conditions: much of the town sits on mudstone and clay soils that can shrink and swell, so foundations near trees often need to go deeper than standard.
• Sloping plots: on hillside roads in areas such as Brixington and Littleham, retaining walls, stepped foundations and extra excavation add cost quickly.
• Access: terraced streets near the town centre often have no side access, so materials are carried through the house and spoil comes out by hand.
• Coastal exposure: salt air and driving rain call for stainless steel fixings, better grade windows and more robust roofing details, especially near the seafront.
• Planning constraints: homes in a conservation area, or on the edge of the East Devon National Landscape, may need particular materials to satisfy East Devon District Council.
• Flood risk: properties close to the Exe Estuary may need a flood risk assessment and raised floor levels or resilient construction.

Why smaller extensions cost more per square metre

Some costs are much the same whatever the size of the job: setting up the site, scaffolding, skips, the steel beam for the knock through, and connecting drainage. Spread over 12 square metres, those fixed costs push the rate well above what you would pay on a 30 square metre build. It is common for a small extension to sit at the top of the range, or above it.

The best ways to keep the rate down are simple ones. Stick to a plain rectangular footprint, choose standard sized doors and windows, leave existing drains where they are if you can, and settle the design before work starts. Changes made halfway through a build are almost always the most expensive ones.