Kitchen extensions with bedrooms above in Portland
Adding a kitchen extension with bedrooms above in Portland gives you two new rooms stacked on one footprint. Here's how we'd approach it, what it typically costs and the rules that apply in England.
Before you start in Portland, here's what applies.
- Postcode districts
- DT5
- County / area
- Dorset, England
- Price region
- South West England
- Guide price
- £57,500–£78,000 (£2,060–£2,780 per m²), kitchen units and worktops priced separately
- Approval route
- It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission.
- Nearest towns
- Weymouth (3.3 miles), Dorchester (10.3 miles), Bridport (17.9 miles)
- Distance to Bournemouth
- about 26.9 miles
- First visit
- Free, no obligation
About a kitchen extension with bedrooms above
This service suits you if your kitchen is too small and you also need another bedroom. Building both floors at once costs less than a single-storey kitchen extension now and a first floor later. You get a layout that works for cooking, eating and the garden, a bedroom plan that works upstairs, the approvals your nation needs and the build, carried out by vetted teams working under S&K. Kitchen units are priced separately.
Around Portland we also work in Weymouth, Dorchester and Bridport, and across the rest of Dorset. Postcode district in and near Portland: DT5.
What it costs in Portland
In South West England, which includes Portland, we'd expect a kitchen extension with bedrooms above to cost around £57,500–£78,000 (kitchen units and worktops priced separately) for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), or £2,060–£2,780 per m² including VAT. The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.
| Spec | Per m² | A 4 m × 3.5 m footprint on two floors (28 m² of new floor space) |
|---|---|---|
| Essential | £1,900–£2,560 per m² | £53,000–£71,500 |
| Standard | £2,060–£2,780 per m² | £57,500–£78,000 |
| Premium | £2,470–£3,340 per m² | £69,000–£93,500 |
Planning and building regulations in Portland
In England, a two-storey rear kitchen extension can be permitted development if it goes no more than 3 m beyond the rear wall of the original house and stays at least 7 m from the rear boundary, with matching materials and roof pitch, outside protected areas. No balconies are allowed. Deeper designs need planning permission, costing £548 (or £575 for applications made from 8 December 2026).
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 Portland homes
Services and drainage
Sinks, dishwashers and an upstairs bathroom all need waste routes to the drains, often near where the extension goes. We check the drains early and plan soil stacks, gas and electrical supplies so the kitchen layout is not limited later.
Bedrooms over a kitchen
Bedrooms above need an escape window or a protected route to the stairs, plus good sound insulation from the kitchen below. We position the stairs, landing and bedroom doors so the new rooms connect naturally to the existing first floor.
How we'd run your project
Measure and listen
A visit to Portland to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Portland.
Engineer it
Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.
Questions about kitchen extensions with bedrooms above in Portland
Do I need planning permission for a kitchen extension with bedrooms above in Portland?
Portland is in England, so England planning rules apply. It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.
How much does a kitchen extension with bedrooms above cost in Portland?
Our guide for South West England, which covers Portland, is £2,060–£2,780 per m² including VAT. A typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £57,500–£78,000 (kitchen units and worktops priced separately). Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Who handles building regulations for a project in Portland?
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.
Is it cheaper to build a kitchen extension and bedrooms at the same time?
Yes, in most cases. Building both floors at once means one set of foundations, one roof, one scaffold and one set of approvals. Adding a first floor later means removing the original roof, possibly strengthening the foundations and disrupting the kitchen again. If you think you will need the bedroom, build it now.
Can I keep using my kitchen during the build?
For part of it. The new structure can be built while your existing kitchen stays in use, but when the rear wall is opened and the new kitchen is fitted there will be several weeks without one. We plan when this happens and help you set up a temporary kitchen elsewhere in the house.
Nearby
Nearby towns we cover for kitchen extensions with bedrooms above:
Other extensions in Portland
All two-storey extension services in Portland · Kitchen extensions with bedrooms above across Dorset
Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Portland.