What is a mansard loft conversion?
A mansard loft conversion rebuilds the roof with a nearly vertical slope (about 72 degrees) and a flat top, effectively adding a new storey. Small dormer windows sit within the steep slope. Mansards are common on period terraces in towns and cities.
How much does a mansard loft conversion cost in Romford?
In Romford, a mansard loft conversion typically costs £84,500–£123,500 for a typical rear mansard, including VAT at 20% (standard rate). Building costs in London run about 30% above the UK average, and the figures for Romford are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rear mansard | £84,500–£123,500 |
| Higher specification | £123,500–£154,500 |
What moves the price most:
- Bathrooms and finishes
- Number of dormers and lead work
- Front, rear or both
- Roof covering: natural slate costs more
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a mansard loft conversion in Romford?
Before anything is built in Romford, we confirm which approvals apply in England. In England a mansard almost always needs planning permission because it changes the roof shape. Many councils publish design guidance for mansards on terraced streets, and some streets are more likely to be approved where neighbours already have one.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
We check this for your address before design work starts, so there are no surprises later.
What we handle
From survey to sign-off, the job normally involves:
- Dormer windows
- Party wall notices to both neighbours
- Planning drawings and application
- Staircase and fire-safe escape route
- Building control sign-off
- Structural design and calculations
How long does it take?
Allow 9 to 12 weeks on site, after planning approval. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Romford
Space is at a premium in London, so homeowners often build out into the side return or up into the roof rather than move.
Romford sits in Greater London, about 14 miles east of central London. We cover the whole of Romford, including postcodes RM1.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about mansard loft conversions in Romford
Does a mansard need planning permission?
Almost always, because it changes the roof shape. Councils assess it against local design guidance.
What roof covering is used?
Natural slate is traditional; some councils accept other materials. We follow local guidance.
Do you build mansard loft conversions in Romford?
Yes. We build mansard loft conversions across Romford, including postcodes RM1. Every project starts with a free home visit.
How much does a mansard loft conversion cost in Romford?
In Romford, a mansard loft conversion typically costs £84,500–£123,500 for a typical rear mansard, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Can I stay at home?
Usually. The new roof is built under a temporary cover so the house stays dry.