Extensions in Whitby: design, planning and build
We design and build house extensions for homes in Whitby and the surrounding North Yorkshire area, with guide prices adjusted for the region.
- Postcode districtsYO21
- Price regionYorkshire and the Humber (×0.94)
- Planning rulesEngland
- Site visitFree, no obligation
Whitby and surrounding towns
Our survey diary covers Whitby, including YO21. The same team covers Redcar (17 miles), Scarborough (18 miles), Middlesbrough (22 miles), Northallerton (33 miles), York (39 miles), all within easy reach. Just over the County Durham border, Thornaby-on-Tees is about 24 miles away.
Approvals for an extension in Whitby
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a single-storey side return infill is often permitted development if it stays within the height limits and is no wider than half the width of the original house. Conservation areas, listed buildings and flats always need an application, and the boundary wall usually brings in the Party Wall Act.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
Popular extension prices in Whitby
Every figure below is a guide for Whitby, adjusted for Yorkshire and the Humber build costs (×0.94) and including VAT. Design and council fees are shown separately on each page.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Conservatory replacement extensions | 14 m² | £28,000 – £36,500 |
| Side return extensions | 11 m² | £24,500 – £31,500 |
| Double-storey extensions | 32 m² | £54,000 – £71,000 |
| Wraparound extensions | 25 m² | £54,000 – £68,500 |
| Single-storey rear extensions | 20 m² | £38,500 – £49,000 |
| Extensions over a garage | 12 m² | £23,500 – £30,500 |
| Kitchen extensions | 20 m² | £39,000 – £50,000 |
Choosing the right extension in Whitby
Yorkshire and the Humber combines stone-built terraces in the Pennine towns with brick semis and newer estates elsewhere, so materials and roof details need matching with care.
For many houses here, double-storey extensions, side return extensions or pitched roof extensions gives the most useful space for the budget.
All extension types we build in Whitby
- Planning permission for extensions · from £300
- Side return extensions · from £16,500
- Wraparound extensions · from £33,500
- Kitchen extensions · from £25,000
- Building regulations for extensions · from £800
- Utility and boot room extensions · from £13,000
- Conservatory replacement extensions · from £18,500
- Home office extensions · from £15,000
- Side extensions · from £20,500
- Bungalow extensions · from £24,500
- Timber frame extensions · from £19,500
- Double-storey extensions · from £35,500
- Bedroom extensions · from £24,000
- Extensions over a garage · from £22,500
- Glass box extensions · from £28,000
- Flat roof extensions · from £19,500
- Annexe extensions · from £51,500
- Porch extensions · from £3,750
- Pitched roof extensions · from £20,500
- Single-storey rear extensions · from £19,500
- Extension plans and drawings · from £1,100
- Orangery extensions · from £28,000
Free site visit
We visit your Whitby home, measure up, talk through what you want and check the planning position.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions about extensions in Whitby
How much does an extension cost in Whitby?
Using our Yorkshire and the Humber factor (×0.94), a standard-spec single-storey extension of 20 m² is a guide £38,500 to £49,000 including VAT, and a 32 m² two-storey extension £54,000 to £71,000. Your written price follows the survey.
Do you cover all of Whitby?
Yes, including the surrounding parts of North Yorkshire. Site visits are free and there is no obligation.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Do I need planning permission for an extension in Whitby?
Not always. It depends on the size, position and your property's history. Many single-storey rear extensions in England are permitted development or can use prior approval.
How long does an extension take in Whitby?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Book a free site visit in Whitby
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.