Velux: the simplest option
A Velux conversion adds rooflights without changing the roof shape. It's the quickest, the cheapest, and almost always permitted development. The catch: you only get the headroom the loft already has. If you measure two metres or more from joist to ridge, a Velux conversion can be brilliant. Below that, you'll need something more invasive.
Dormer: the Bristol classic
A box dormer at the rear is the workhorse of Bristol loft conversions. It gives you a flat ceiling, proper headroom across the room, and usually fits Victorian and Edwardian terraces in BS3, BS6 and BS7 without planning. The roof line at the front stays the same, so the street view is untouched. About 70% of the lofts we do in Bristol end up as rear dormers.
Hip-to-gable: for semis and end-terraces
If your roof has a sloping side (a hip), hip-to-gable squares it off with a vertical wall, opening up the entire loft. It works particularly well on 1930s semis in Henleaze, Westbury Park and Henbury. It usually needs full planning rather than permitted development, but it gains the most headroom of any option without rebuilding the whole roof.
Mansard: the most space, the most work
A mansard rebuilds the entire roof structure with steep walls and a near-flat top, giving you a near-full storey upstairs. Common in conservation areas where the planners want to retain a particular roof line, and on Georgian properties in Clifton and Hotwells. It's the longest, most expensive option, but you end up with a proper extra floor.
How to choose
Start with headroom. Get a builder to measure from finished joist to ridge, anything under 2.2m makes a Velux marginal. Then check planning: is your home in a conservation area? Listed? On a corner? Then think about how you want to use the space, a bedroom with en-suite needs more usable floor than a study. We give an honest recommendation on the first site visit.
Stair position is the make-or-break detail
The single decision that ruins more loft conversions than any other is staircase position. Get it wrong and you eat a bedroom on the floor below or end up with a cramped landing in the loft. We work the stair into the design before drawings are finalised, not after.