Is my loft suitable for a conversion?

By Ajay Singh. Published 30 October 2026.

Most lofts in houses and bungalows can be converted, at a price. The things that decide it are the height, the roof structure, where a stair can go and how you'd get out in a fire. You can check the first two yourself in about ten minutes.

The measurements below come from the Scottish Government's Building Standards Technical Handbook: Domestic, April 2026, which applies to warrant applications from 6 April 2026. It's guidance on meeting the regulations, and a designer can show other ways to comply. Clause numbers are given so you can look them up.

1. Head height

Measure from the top of the ceiling joists to the underside of the ridge at the highest point. Then take off what a new floor and an insulated ceiling will use, and think about how much of the floor you'd actually be able to stand up on. A sloping roof gives you a narrow strip of full height unless a dormer pushes it out.

The handbook doesn't give one pass-or-fail height for a loft. What it does give:

• 1.8 m unobstructed height for activity spaces in the "enhanced apartment" and kitchen (clause 3.11.4). The enhanced apartment is the main room on your principal living level, so this usually won't apply to a loft bedroom.
• Every apartment should fit a bed, wardrobe and chest of drawers, with room to use them (clause 3.11.1).
• 2.0 m clear headroom over the stair (clause 4.3.16).

Low height doesn't necessarily rule it out. It may just change the type: rooflights where there's plenty of height, a dormer where there's less, and a raised roof where there's very little. Those get more expensive in that order.

2. Roof structure

Stick your head through the hatch. What you see is the main factor in the price.

• Traditional cut roof. Rafters along the slope, a ridge board at the top, and mostly open space in the middle. This is the easier kind. Older houses tend to have these.
• Trussed roof. Factory-made timbers in a repeating W or M shape across the whole loft. These hold the roof up, so you can't just cut them. It needs a new structure, usually steel, and MyJobQuote (9 October 2026) says this takes more time, labour and materials.

Whichever you have, a structural engineer has to check it. The new floor has to carry a room, and the ceiling joists under it weren't designed to. Take a photo for the firm. It saves a lot of guesswork.

3. Room for a stair

This is the thing people underestimate. A stair needs to arrive somewhere with headroom, usually under the highest part of the roof or under a dormer. Under the handbook's guidance for a private stair:

• Rise of each step: 100 mm to 220 mm. Going: at least 225 mm. Maximum pitch: 42° (clause 4.3.2).
• Width: 900 mm, or 800 mm with a handrail on both sides. It can be 600 mm where the stair serves only sanitary accommodation or one room, other than a kitchen, accessible toilet or enhanced apartment (clause 4.3.3).
• Clear headroom: 2.0 m over the width of the stair (clause 4.3.16).

That 600 mm allowance can be a real help if the loft is one room, but check how it would work with your designer. Loft ladders don't count as a stair for a habitable room, in our reading of these clauses. Stand on your landing and work out what you'd give up.

4. Getting out in a fire

This is where a loft conversion changes the rest of the house. Table 2.3 and clause 2.9 of the handbook set out what's recommended, based on how high the top storey is above the ground outside.

The handbook says a typical two-storey house normally has a top storey under 4.5 m. Add a floor and you will usually go over it. So on a two-storey house you should expect the existing stair to become part of a protected enclosure: a complete fire-resisting route from every apartment on that top storey to an exit door, with self-closing fire doors except on a toilet or bathroom (clause 2.9.5). That can mean new doors throughout the upstairs and downstairs hall. In an open-plan house, that's a real design issue.

In a bungalow, the converted loft is often the first upper floor, and may be under 4.5 m. Then you'd normally be looking at an escape window in each room: an unobstructed opening of at least 0.33 m², at least 450 mm high and wide, with the bottom no more than 1,100 mm above the floor (clause 2.9.4). Measure it for your own house, as ground levels vary.

All homes need a fire detection and alarm system, with detectors in living rooms, kitchens and circulation spaces (clause 2.11.1). Since this is a conversion, the handbook says it's essential to agree early with the verifier, the council's building standards team, where meeting a standard in full isn't reasonably practicable (clause 0.12.1).

5. Things outside the loft

• Planning limits. See our planning guide. A corner plot or a short back garden can change the design.
• Shared walls. On a semi or terrace, the wall and chimney between you and next door may be affected. Talk to your neighbours early.
• Flats. If you share a roof, first find out who owns it.
• Bats. They're protected. Mention anything you've seen, because a survey may be needed.
• The state of the roof. A roof near the end of its life is better replaced while the scaffolding's up.

A quick self-check

1. Is it a house or bungalow, not a flat?
2. Can you stand upright under the ridge and walk a few steps?
3. Does the hatch show open rafters, not a web of trusses? (Trusses aren't a dead end, but they do cost more.)
4. Can you see where a stair would land without losing a bedroom?
5. Does the back of the house face away from a road, with a boundary 10 metres or more away?

Four or five yeses means it's well worth getting a firm in to look. Fewer doesn't rule it out, but ask about a garage conversion or garden room too. Check the costs on our cost guide.

Rules, dates and prices on this page were last checked on 30 October 2026.