How do I know if my loft can be converted?

Measure the head height under the ridge and look at whether the roof is cut timber or trusses. Those two facts tell you most of what you need to know, and we check both on the first visit.

Does a loft conversion need planning permission?

Many are permitted development, but volume limits, front roof slope changes and designations can remove that. Confirm your position with your local planning authority or the Planning Portal.

Is a dormer worth the extra cost?

Where it converts sloping unusable area into standing room, usually yes. Where head height is already generous, rooflights may do the job for considerably less.

How disruptive is it?

Less than an extension for most of the programme, because much of the work happens above you, but the stair opening and first fix weeks are genuinely disruptive.

Cost guide · Cornwall

Loft conversion costs in Cornwall, four variables and everything else is detail

Loft conversion prices spread more widely than any other domestic project, and the reason is that the starting conditions vary so much. A traditional cut roof with generous head height and an obvious stair position is a different job to a trussed roof on a low ridge, even in identical looking houses on the same street.

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Variable one, head height

Available height under the ridge decides whether the loft is convertible at all, and how much dormer you need to make it usable. It is the first thing measured on any feasibility visit, because everything else follows from it.

Variable two, the stair

The stair has to arrive with proper head height and it has to come from somewhere. In many Cornish houses that means giving up part of a bedroom below, and the cost of making good that room is a genuine part of the loft budget that quotes routinely omit.

Variable three, roof structure

A traditional cut roof can often be opened up with relatively modest structural work. A trussed roof has to be structurally replaced within the loft space before the floor can carry habitable loads, and that is a significant cost difference.

Variable four, dormer or rooflight

Rooflights are cheaper and less contentious but add no head height. Dormers add usable floor area and cost more. The comparison worth making is cost per usable square metre rather than cost overall, because a cheap conversion that produces an unusable room is not cheap.

Rooflight conversion: least cost, no change to roof form, no added head height
Pitched roof dormer: sits comfortably on traditional slate roofs, moderate added area
Box dormer: most usable floor area, heaviest visually, most likely to attract planning attention

Building regulations are not optional

Floor structure, escape strategy, stair design, fire separation and insulation all have to be designed and approved. A conversion signed off correctly is what protects you at resale, and one that was not is one of the more common reasons a sale stalls.

Frequently asked

Straight answers.

How do I know if my loft can be converted?: Measure the head height under the ridge and look at whether the roof is cut timber or trusses. Those two facts tell you most of what you need to know, and we check both on the first visit.
Does a loft conversion need planning permission?: Many are permitted development, but volume limits, front roof slope changes and designations can remove that. Confirm your position with your local planning authority or the Planning Portal.
Is a dormer worth the extra cost?: Where it converts sloping unusable area into standing room, usually yes. Where head height is already generous, rooflights may do the job for considerably less.
How disruptive is it?: Less than an extension for most of the programme, because much of the work happens above you, but the stair opening and first fix weeks are genuinely disruptive.

Thinking about the loft?

Book a free feasibility visit and we will measure head height and stair options before you spend anything.

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