Building services in Barnet
House extensions
- Single-storey extensions
- Double-storey extensions
- Side extensions
- Side return extensions
- Wraparound extensions
- Kitchen extensions
- Orangeries
- Glazed and contemporary extensions
- Porches
Loft conversions
- Dormer loft conversions
- Hip-to-gable loft conversions
- Mansard loft conversions
- Rooflight loft conversions
- Bungalow loft conversions
Garage, basement and barn conversions
New build homes
Renovations and structural work
Design and approvals
Guide prices in Barnet
| Project | Guide range (inc VAT) |
|---|---|
| Single-storey extensions | £2,550–£3,750 per m² of floor area |
| Kitchen extensions | £2,900–£4,400 per m² including a mid-range kitchen |
| Garage conversions | £23,500–£39,000 for a single integral garage |
| House renovations | £1,150–£2,350 per m² for a medium to full renovation |
| Porches | £8,500–£21,000 from a 3 m² porch to a small front extension |
| Orangeries | £3,100–£4,400 per m² of floor area |
We start from a UK-wide guide and adjust it for London, where labour and materials are typically about 30% above average.
Planning permission in Barnet
In England a single-storey rear extension is often permitted development: broadly up to 3 metres deep on a semi-detached or terraced house and 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres within 2 metres of a boundary, and covering no more than half the garden. The larger home extension scheme allows up to 6 or 8 metres if you notify the council first and neighbours have a chance to comment. In conservation areas, National Parks and National Landscapes the larger home extension route, side extensions and cladding are not permitted development. Flats and houses whose rights have been removed need a planning application, and listed buildings need listed building consent.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
About building in Barnet
Space is at a premium in London, so homeowners often build out into the side return or up into the roof rather than move.
If your home is in Barnet or close by in Potters Bar, Mill Hill and Borehamwood, a free home visit is the first step.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions from homeowners in Barnet
Do I need planning permission for an extension in Barnet?
In England a single-storey rear extension is often permitted development: broadly up to 3 metres deep on a semi-detached or terraced house and 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres within 2 metres of a boundary, and covering no more than half the garden. The larger home extension scheme allows up to 6 or 8 metres if you notify the council first and neighbours have a chance to comment. In conservation areas, National Parks and National Landscapes the larger home extension route, side extensions and cladding are not permitted development. Flats and houses whose rights have been removed need a planning application, and listed buildings need listed building consent.
How much does a loft conversion cost in Barnet?
A rear dormer loft conversion in Barnet typically costs £62,500–£88,500 for a typical rear dormer with en-suite, including VAT.
How much does an extension cost in Barnet?
A single-storey extension in Barnet typically costs £2,550–£3,750 per m² of floor area, and a double-storey extension £2,150–£3,250 per m² of floor area (both floors), including VAT.
Is the home visit free?
Yes. The first visit to discuss your project and measure up for a quote is free, with no obligation.
Do you work in Barnet?
Yes. We take on extensions, loft conversions, conversions, renovations and new builds across Barnet, including postcodes EN5.