Extensions in Bangor, Gwynedd: design, planning and build
Looking to extend your home in Bangor, Gwynedd? Start here: extension types, guide prices for Bangor, Gwynedd, the planning rules that apply and how a project runs.
- Postcode districtsLL57, LL59
- Price regionWales (×0.93)
- Planning rulesWales
- Site visitFree, no obligation
Bangor, Gwynedd extension prices at a glance
Use these Bangor, Gwynedd guide prices to sense-check a budget; the guide-price tool narrows them to your own size, and the site visit turns them into a written figure.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Wraparound extensions | 25 m² | £53,000 – £67,500 |
| Single-storey rear extensions | 20 m² | £38,000 – £48,500 |
| Conservatory replacement extensions | 14 m² | £27,500 – £36,000 |
| Orangery extensions | 16 m² | £41,500 – £52,500 |
| Double-storey extensions | 32 m² | £53,500 – £70,000 |
| Extensions over a garage | 12 m² | £23,000 – £30,500 |
| Side return extensions | 11 m² | £24,500 – £31,000 |
Where we work near Bangor, Gwynedd
We cover Bangor, Gwynedd and the postcode districts LL57, LL59. Nearby, we also take on projects in Caernarfon (7 miles), Llangefni (8 miles), Holyhead (19 miles). Just over the Clwyd border, Llandudno is about 14 miles away.
Planning and building control in Bangor, Gwynedd
In Wales a single-storey rear extension can usually project up to 4 m beyond the rear wall without a planning application, if it is no more than 4 m high, keeps eaves to 3 m and overall height to 4 m within 2 m of a boundary, and covers no more than half the land around the original house. Wales has no larger home extension prior approval scheme.
In Wales a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house, and it must not come closer to a highway than the existing side wall. Larger side extensions need planning permission.
In a conservation area, national park, National Landscape or 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.
The Party Wall etc. Act 1996 applies in Wales as in England: notice must be served before work to a shared wall, building on the boundary, or excavating close to a neighbour's foundations.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
Which extension suits a Bangor, Gwynedd home?
Welsh housing ranges from stone terraces in the valleys to render-and-slate houses and modern estates, and the Welsh planning rules differ from England's in several places.
Depending on the plot, bungalow extensions and single-storey rear extensions are often the strongest options, with side return extensions worth considering where there is room.
Extension types and starting prices
- Double-storey extensions · from £35,000
- Timber frame extensions · from £19,500
- Extensions over a garage · from £22,000
- Building regulations for extensions · from £800
- Conservatory replacement extensions · from £18,500
- Side return extensions · from £16,500
- Kitchen extensions · from £25,000
- Bungalow extensions · from £24,000
- Utility and boot room extensions · from £13,000
- Annexe extensions · from £51,000
- Planning permission for extensions · from £300
- Home office extensions · from £14,500
- Pitched roof extensions · from £20,500
- Porch extensions · from £3,700
- Glass box extensions · from £27,500
- Bedroom extensions · from £24,000
- Single-storey rear extensions · from £19,500
- Wraparound extensions · from £33,000
- Orangery extensions · from £27,500
- Flat roof extensions · from £19,500
- Side extensions · from £20,000
- Extension plans and drawings · from £1,100
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions about extensions in Bangor, Gwynedd
How much does an extension cost in Bangor, Gwynedd?
Using our Wales factor (×0.93), a standard-spec single-storey extension of 20 m² is a guide £38,000 to £48,500 including VAT, and a 32 m² two-storey extension £53,500 to £70,000. Your written price follows the survey.
Do I need planning permission for an extension in Bangor, Gwynedd?
Not always. It depends on the size, position and your property's history. In Wales many single-storey rear extensions up to 4 m are permitted development.
Will my neighbours need to be told?
If you apply for planning the council notifies them, and in Wales party wall notices may be needed for work near a shared boundary.
How long does an extension take in Bangor, Gwynedd?
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 Bangor, Gwynedd
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.