Kitchen-diner rear extensions

How should a kitchen-diner extension be laid out?

We start from where you cook and where you sit. The working kitchen usually stays in the old part of the house, where the drainage and gas already run, and the dining table and sofa move into the new space nearest the glass. An island between them gives a place to prepare food facing the garden.

Daylight is the other half of the plan. A roof lantern or rooflights over the old back room stop the kitchen becoming a dark corridor, and a wide opening into the house keeps the rooms reading as one space.

How much does a kitchen extension cost?

The building work is priced like a single-storey rear extension, £1,900–£3,100 per square metre including VAT for a standard specification, so a 4 m × 5 m extension typically comes to £38,000–£62,000. The kitchen itself is extra: allow £10,000 to £25,000 for units, worktops and appliances depending on the range. We can install a kitchen you buy yourself, or one supplied through us.

Do you need planning permission?

In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.

How long will we be without a kitchen?

Usually four to six weeks. The extension shell is built while the old kitchen still works; the existing kitchen comes out only when the new room is ready for first-fix plumbing and electrics.

What is included?

• Layout plan with kitchen, dining and seating zones
• Drainage and gas rerouted
• Extraction ducted to outside
• Underfloor heating options
• Roof lantern or rooflights over the kitchen
• Utility or boot room if space allows
• Kitchen installation (yours or supplied)
• Lighting plan and sockets for the island

Guide prices by region

Per square metre of new floor, including VAT, standard specification.