Covering Dartford
Alongside Dartford, we also cover Bexley, Swanley (4 miles to the south-west) and Welling.
Homes in the South East
The South East has a lot of 1930s and post-war semi-detached housing, well suited to rear extensions and hip-to-gable loft conversions, alongside period properties in conservation areas that need a more careful design.
What is a loft conversion?
We start with the head height. You need roughly 2.2 m or more from the top of the ceiling joists to the underside of the ridge for a conversion to work without raising the roof. From there we design the staircase position, the type of conversion and the en-suite, and manage the whole build including fire safety and building control.
- Loft survey and head-height check
- Design drawings and structural calculations
- En-suite, electrics, heating and fire safety upgrades
What is the guide price for a loft conversion in Dartford?
Use these ranges to budget for loft conversions; the survey turns them into a fixed price for the agreed specification.
| Loft conversions | Guide price incl. VAT |
|---|---|
| Rooflight conversion | £30,000 to £45,000 |
| Dormer conversion | £50,000 to £90,000 |
| Hip-to-gable with dormer | £60,000 to £95,000 |
| Mansard conversion | £65,000 to £110,000 |
How is a loft conversion approved in Dartford?
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 many loft conversions are permitted development: the extra roof volume must stay within 40 m³ on a terraced house or 50 m³ on a semi or detached house, nothing can sit higher than the existing ridge, no dormer can face a road on the main elevation, and side windows must be obscure-glazed and non-opening below 1.7 m.
What can change the price or programme?
- Fire safety rules can mean new fire doors on the floors below.
- Party wall notices are often needed for steels bearing on a shared wall.
From first call to completion
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
Your questions answered
How much does a loft conversion cost?
Roughly £30,000 to £45,000 for a rooflight conversion, £50,000 to £90,000 for a dormer, £60,000 to £95,000 for a hip-to-gable and £65,000 to £110,000 for a mansard, including VAT.
Does a loft conversion need planning permission?
In England many are permitted development, within 40 m³ of extra volume on a terrace or 50 m³ on a semi or detached house. Conservation areas and flats need permission.
Do you work in Dartford?
Yes. Dartford is within our coverage for loft conversions, along with nearby Bexley and Swanley.
Loft conversions near Dartford
- Loft conversions in Bexley
- Loft conversions in Swanley
- Loft conversions in Welling
- Loft conversions in South Ockendon
Learn more about loft conversions, or see every project we cover in Dartford.

