Bungalow and upward extensions in Welwyn Garden City

Covering Welwyn Garden City

Welwyn Garden City is about 6 miles north-east of St Albans. We also cover Hatfield (3 miles to the south), Hertford and St Albans.

Homes in the East of England

Housing in the East of England ranges from post-war estates and modern developments to timber-framed and period homes in historic towns, so permitted development checks and conservation controls both feature regularly.

What does an upward extension involve?

An upward extension adds a new storey on top of an existing house, most often turning a bungalow into a two-storey or chalet-style home. It can double the floor area without using any of the garden.

Structural survey of walls and foundations
Roof removal and temporary weather protection
Staircase and changes to the ground floor layout

How much should I budget for an upward extension?

Typical ranges for bungalow and upward extensions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.

Bungalow and upward extensions	Guide price incl. VAT
Chalet conversion with dormers (total)	£45,000 to £85,000
New first floor, standard specification	£2,200 to £2,800 per m²
New first floor, good specification	£2,800 to £3,300 per m²
New first floor, high specification	£3,300 to £3,800 per m²

How is an upward extension approved in Welwyn Garden City?

In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it applies.

In England, Class AA permitted development allows an extra storey on many detached and semi-detached houses built between July 1948 and October 2018, subject to a prior approval application covering design, neighbours’ amenity and other matters. Houses in conservation areas and other protected land need full planning permission, as do most chalet conversions with front dormers.

What can affect an upward extension?

The house is exposed while the roof is off, so the sequence is planned tightly.
Neighbours’ light and privacy are the main planning tests.

What are the steps?

Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

Bungalow and upward extensions: common questions

Can I add a first floor to my bungalow?

Often yes, if the walls and foundations can carry the load and planning allows. We check the structure first.

Is an upward extension permitted development?

In England, Class AA allows it on many post-1948 houses through a prior approval application. Elsewhere planning permission is needed.

Do you work in Welwyn Garden City?

Yes. Welwyn Garden City is within our coverage for bungalow and upward extensions, along with nearby Hatfield and Hertford.

Also covering

Learn more about bungalow and upward extensions, or see every project we cover in Welwyn Garden City.