What types of loft conversion are there, and which adds the most value?

The main options are rooflight (often called by the brand name of skylight Velux), dormer, hip-to-gable and mansard. Dormers are the most popular because they add significant floor space and headroom at a sensible cost. Mansards create the most space but involve the biggest structural changes. A well-designed loft conversion with an en-suite could add 15 to 20% to a property’s value. If you’re weighing up a loft conversion against an extension, our guide on what build project is best for your house compares the two.