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 Guiseley?
In Guiseley, a mansard loft conversion typically costs £60,500–£88,500 for a typical rear mansard, including VAT at 20% (standard rate). Prices across Yorkshire and the Humber are typically 7% below the UK average for this kind of work, which is reflected in the range for Guiseley. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rear mansard | £60,500–£88,500 |
| Higher specification | £88,500–£110,500 |
What moves the price most:
- Roof covering: natural slate costs more
- Scaffolding on busy streets
- Party wall surveyor fees
- Bathrooms and finishes
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 mansard loft conversion in Guiseley?
Here is how the rules work for a mansard loft conversion 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
Handled as part of most mansard loft conversions:
- Insulation, electrics, plumbing and plastering
- Dormer windows
- New roof structure, slate or tile covering and lead work
- Party wall notices to both neighbours
- Structural design and calculations
- Building control sign-off
How long does it take?
Build time is typically 9 to 12 weeks on site, after planning approval. Before that, surveys, drawings and approvals usually take 3 to 4 months, longer if the council asks for changes.
Building in Guiseley
Yorkshire and the Humber has stone and brick terraces as well as inter-war and newer estates, so materials matching is an early design question.
We work across Guiseley and neighbouring areas such as Yeadon, Shipley and Horsforth. Postcodes we cover in Guiseley include LS20.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 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
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about mansard loft conversions in Guiseley
Does a mansard need planning permission?
Almost always, because it changes the roof shape. Councils assess it against local design guidance.
Do you build mansard loft conversions in Guiseley?
Yes. We build mansard loft conversions across Guiseley, including postcodes LS20. Every project starts with a free home visit.
Can I stay at home?
Usually. The new roof is built under a temporary cover so the house stays dry.
Do I need party wall agreements?
Yes, mansards on terraced houses almost always involve both party walls.
How much does a mansard loft conversion cost in Guiseley?
In Guiseley, a mansard loft conversion typically costs £60,500–£88,500 for a typical rear mansard, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.