Two-storey extensions in Gwynedd and Anglesey
We cover all of Gwynedd and Anglesey for two-storey and first-floor extensions. Pick a town or an extension type below.
Gwynedd and Anglesey at a glance
- Nation
- Wales
- Price region
- Wales
- Postcode areas
- LL
- Main town
- Bangor (Gwynedd and Anglesey)
- Towns listed
- 10
- Site visits
- Free, no obligation
Choose your town
- Bangor (Gwynedd and Anglesey)
- Holyhead
- Caernarfon
- Llangefni
- Bethesda
- Pwllheli
- Blaenau Ffestiniog
- Menai Bridge
- Amlwch
- Tywyn
Guide prices in Wales
| Extension type | Per m² | Typical project |
|---|---|---|
| Two-storey rear extension | £1,840–£2,480 per m² | £51,500–£69,500 |
| Two-storey side extension | £1,890–£2,530 per m² | £79,000–£106,500 |
| Two-storey wraparound extension | £1,980–£2,710 per m² | £111,000–£152,000 |
| Part single, part two-storey | £1,840–£2,530 per m² | £66,000–£91,000 |
| Extension over a garage | £1,610–£2,350 per m² | £29,000–£42,000 |
| First-floor extension over an existing single storey | £1,660–£2,390 per m² | £23,000–£33,500 |
| Two-storey front extension | £2,020–£2,760 per m² | £24,500–£33,000 |
Including VAT, Standard spec. See all prices and fees.
The main places we list in Gwynedd and Anglesey are Bangor (Gwynedd and Anglesey) (LL57), Holyhead (LL64), Caernarfon (LL54), Llangefni (LL60), Bethesda (LL57), Pwllheli (LL51), Blaenau Ffestiniog (LL41) and Menai Bridge (LL56). We cover the villages in between too.
Which type suits your house?
If you're not sure which type fits, that's what the free visit is for. We'll sketch the realistic options for your house in Gwynedd and Anglesey, with a rough idea of the approval route and cost for each.
The rules in Wales
Gwynedd and Anglesey is in Wales. Two-storey rear: ground floor up to 4 m, first floor up to 3 m and 10.5 m from the rear boundary. Some two-storey side extensions can be permitted development. Householder planning application: £585. Councils normally decide householder applications within 8 weeks.
The full Wales rules explained
Extension types
- Two-storey rear extensions
- Two-storey side extensions
- Two-storey wraparound extensions
- Part single, part two-storey extensions
- Extensions over a garage
- First-floor extensions
- Two-storey front extensions
By house type
- Two-storey extensions for semi-detached houses
- Two-storey extensions for detached houses
- Two-storey extensions for end-of-terrace houses
Rooms and uses
- Kitchen extensions with bedrooms above
- Extra bedroom and en-suite extensions
- Two-storey annexe extensions
- Garage conversions with a room above
Design and approvals
- Two-storey extension plans and drawings
- Planning permission for two-storey extensions
- Structural engineering for two-storey extensions
- Building regulations for two-storey extensions
- Party wall notices for extensions
- Design and build two-storey extensions
Questions about extensions in Gwynedd and Anglesey
How much does a two-storey extension cost in Gwynedd and Anglesey?
In Wales our guide for a two-storey rear extension is £1,840–£2,480 per m² including VAT, about £51,500–£69,500 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). Side and wraparound extensions cost a little more per m².
Do I need planning permission in Gwynedd and Anglesey?
Two-storey rear: ground floor up to 4 m, first floor up to 3 m and 10.5 m from the rear boundary. Some two-storey side extensions can be permitted development. Householder planning application: £585.
Do you cover the whole of Gwynedd and Anglesey?
Yes. We list the main towns here, but we cover the whole of Gwynedd and Anglesey including villages. The first site visit is free.
What happens at the first visit?
We look at your house, the boundaries, access and drains, talk through what you need and explain the approvals. Then we price the design stage, including the measured survey, in writing.