What is a rooflight loft conversion?

A rooflight loft conversion (sometimes called a roof window conversion) keeps the existing roof shape and adds roof windows that sit flush with the slope. The floor is strengthened, a staircase is added and the space is insulated and finished.
How much does a rooflight loft conversion cost in Basildon?
In Basildon, a rooflight loft conversion typically costs £32,000–£47,500 for a typical rooflight conversion, including VAT at 20% (standard rate). The guide for Basildon reflects typical costs in the East of England, roughly 6% above the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rooflight conversion | £32,000–£47,500 |
| Higher specification | £47,500–£59,500 |
The main things that change the cost:
- Floor and roof strengthening
- Bathroom or not
- Storage and finishes
- Number of roof windows
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a rooflight loft conversion in Basildon?
Whether you need planning permission depends on your house and its location in England. In England roof windows are permitted development if they project no more than 15 centimetres from the roof slope and side-facing windows are obscure-glazed. Listed buildings need 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.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
On a typical rooflight loft conversion we handle:
- Roof windows installed
- Staircase and fire-safe escape route
- Drawings and structural calculations
- Electrics, heating and plastering
- Floor joists and any steel beams
- Insulation between and under rafters
How long does it take?
Expect 4 to 6 weeks on site. Design and approvals come first and typically take 6 to 12 weeks, depending on the approval route.
Building in Basildon
Many towns in the East of England have estates built since the 1970s, where garage conversions and rear extensions are popular.
If your home is in Basildon or close by in Pitsea, Stanford-le-Hope and Wickford, a free home visit is the first step.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 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 about rooflight loft conversions in Basildon
Who approves a rooflight loft conversion in Basildon?
Planning matters in Basildon go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
Is it cheaper than a dormer?
Yes, usually, because the roof shape stays the same. But you gain less full-height floor space.
How much does a rooflight loft conversion cost in Basildon?
In Basildon, a rooflight loft conversion typically costs £32,000–£47,500 for a typical rooflight conversion, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Can I have a bathroom?
Yes, where there is enough head height at the shower or bath position.
How much head height do I need?
Around 2.2 metres or more from the top of the ceiling joists to the ridge is a good starting point. Insulation and new floor joists reduce the height.
