Dormer loft conversions in Horsham

Covering Horsham

Horsham sits 7 miles south-west of Crawley, with Crawley 7 miles to the north-east and Horley 11 miles to the north-east.

Homes in the South East

Many South East homes are inter-war or post-war semis and detached houses with room for rear and side extensions, while historic town centres and villages bring conservation area and listed building controls.

What is a dormer loft conversion?

Rear dormers on terraced and semi-detached houses are often permitted development in England. We size the dormer to fit the volume allowance, clad it to suit the house (tile-hanging, render, slate or zinc) and fit out the room and en-suite below.

Steelwork and new floor structure
Dormer frame, roof covering and cladding
En-suite, electrics and fire-protected escape route

How much should I budget for a dormer loft conversion?

Use these ranges to budget for dormer loft conversions; the survey turns them into a fixed price for the agreed specification.

Dormer loft conversions	Guide price incl. VAT
Rear dormer, bedroom only	£50,000 to £65,000
Full-width dormer with en-suite	£60,000 to £80,000
L-shaped dormer (over rear outrigger)	£65,000 to £90,000

Planning and building rules in Horsham

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 can change the price or programme?

Dormers on the front of the house facing a road are not permitted development in England.
A flat dormer roof needs proper falls and a quality membrane.

What are the steps?

Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.

Questions about a dormer loft conversion in Horsham

Is a dormer permitted development?

Rear dormers in England often are, within the 40 m³ (terrace) or 50 m³ (semi or detached) volume allowance. Front dormers facing a road are not.

How long does a dormer conversion take?

Around 8 to 12 weeks on site.

Can you visit a house in Horsham 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.

Dormer loft conversions near Horsham

Learn more about dormer loft conversions, or see every project we cover in Horsham.