Covering Harpenden
Harpenden is about 5 miles north of St Albans. We also cover St Albans (5 miles to the south), Luton and Hemel Hempstead.
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 goes into an upward extension?
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
- Staircase and changes to the ground floor layout
- Full fit-out of the new rooms
What is the guide price for an upward extension in Harpenden?
Use these ranges to budget for bungalow and upward extensions; the survey turns them into a fixed price for the agreed specification.
| 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 |
What approvals does an upward extension need in England?
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 should Harpenden homeowners check first?
- The staircase takes space from the ground floor plan.
- Neighbours’ light and privacy are the main planning tests.
What happens after I enquire?
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- 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.
Questions about an upward extension in Harpenden
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.
How do I get a price for bungalow and upward extensions in Harpenden?
Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.
Also covering
- Bungalow and upward extensions in St Albans
- Bungalow and upward extensions in Luton
- Bungalow and upward extensions in Hemel Hempstead
- Bungalow and upward extensions in Welwyn Garden City
Learn more about bungalow and upward extensions, or see every project we cover in Harpenden.

