How much does a loft conversion cost in the UK?

I've completed over forty loft conversions in West Yorkshire and the most common question is always about cost. A basic Velux conversion with two windows, boarding, insulation, electrics, and a fixed staircase typically runs between £22,000 and £30,000. If you want a dormer to gain proper headroom and a usable bedroom with an en suite, expect £38,000 to £55,000 depending on the size of the dormer and the spec of the bathroom. Our full loft conversion cost guide breaks this down in more detail.

Location makes a significant difference. In Bristol and the South West, a rear dormer loft conversion with a shower room averages around £42,000 to £50,000 including structural steelwork, building regulations sign-off, and all finishes. In London you can add twenty to thirty per cent on top of those figures. The key cost drivers are the type of conversion, the structural work needed, and whether you require planning permission. A hip-to-gable conversion costs more than a standard dormer because of the additional roof restructuring involved.

People underestimate the extras. Your builder's quote should include scaffolding, skip hire, building control fees, and a completion certificate. I always tell clients to budget an additional ten per cent for unforeseen work — things like upgrading the existing floor joists or relocating a water tank. A mansard conversion, which is the most expensive option, can reach £60,000 to £70,000 in the North, but it adds the most usable space and the highest return on your property value.