Side Dormer Loft Conversions
Side dormer and double dormer loft conversions explained: costs from £28,000, planning permission rules, headroom gained and build times. Yorkshire specialists — free survey.
What Is a Side Dormer Loft Conversion?
A side dormer is built into the side slope of the roof rather than the rear, lifting the roofline along the flank of the house so you gain full standing height where the eaves would otherwise make the loft unusable — typically over the new staircase, along a landing or inside an en-suite.
Double Dormer Loft Conversions
A double dormer conversion uses two dormers, either on the same elevation or one on each slope, so a larger loft can be split into two usable rooms each with its own window and full-height ceiling.
Side Dormer Costs
- Single side dormer: £28,000–£40,000, 5–7 weeks on site
- Double dormer (two dormers): £38,000–£52,000, 7–9 weeks
- Side dormer plus rear dormer: £45,000–£62,000, 8–10 weeks
- Hip to gable plus side dormer: £48,000–£65,000, 10–12 weeks
Planning Permission for a Side Dormer
Side dormers can be Permitted Development, but side-facing windows must be obscure-glazed and non-opening below 1.7m, the dormer must sit 20cm back from the eaves and stay below the ridge, within the 40m³ or 50m³ volume allowance. Conservation areas and Article 4 zones need a full application.
Get in touch
Call 07526 739253 or 01423 638367.
Email enquiries@dormerking.uk.
Based in Knaresborough, North Yorkshire — serving Harrogate, Leeds, York, Ripon, Wetherby, Nidderdale and Pateley Bridge.