How Much Does a Loft Conversion Cost?
£20,000 – £65,000
depending on type
A loft conversion costs between £20,000 and £65,000 depending on the type, the roof structure, and the level of finish. A basic Velux conversion that adds rooms without altering the roofline is the cheapest option; a full dormer or mansard conversion that dramatically increases headroom and floor space sits at the top of the range.
Average cost
£20,000 – £65,000
depending on type
Prices vary by region, property type and tradesperson. Always get at least two quotes.
What affects the price?
Conversion type - a Velux conversion starts from £20,000; a full dormer costs £35,000-£55,000; a mansard or hip-to-gable costs £50,000-£65,000
Roof structure - cut rafter roofs are cheaper and easier to convert than trussed rafter roofs which require structural modifications
Specification - basic stud walls and carpet vs en-suite bathroom, bespoke joinery, and Juliet balcony
Professional fees - structural engineer, architect, building control, and potentially planning application add £2,000-£6,000
Labour vs materials
A typical loft conversion project takes 6-10 weeks from start to practical completion. Labour costs usually represent 40-50% of the overall project cost, with materials and subcontractors making up the rest.
Questions to ask your tradesperson
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