Covering Thamesmead
Thamesmead sits 11 miles east of London, with Barking 3 miles to the north-west and Welling 3 miles to the south.
Homes in London
London projects often mean working on period terraces with neighbours on both sides, tight access through the house and conservation area controls, so careful planning and party wall work matter as much as the build.
What does a loft conversion involve?
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
- Planning or lawful development certificate
How much does a loft conversion cost in Thamesmead?
Indicative costs for loft conversions. London and the South East usually sit towards the top of each range.
| 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 |
Do you need permission for a loft conversion in Thamesmead?
Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 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 should Thamesmead homeowners check first?
- Head height under the ridge decides whether a conversion is practical.
- Party wall notices are often needed for steels bearing on a shared wall.
From first call to completion
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- 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.
What people ask before starting
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.
Can we live at home during a loft conversion?
Yes. Most of the work is done from scaffolding until the staircase goes in near the end.
Can you visit a house in Thamesmead to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Also covering
- Loft conversions in Barking
- Loft conversions in Welling
- Loft conversions in Becontree
- Loft conversions in Dagenham
Learn more about loft conversions, or see every project we cover in Thamesmead.

