How much head height do I actually need?

As a working rule you want around 2.4m from existing floor to the underside of the ridge before conversion, because floor and ceiling build-ups consume it. Less than that, and you are looking at lowering ceilings below or raising the roof, both of which change the project entirely.

Is a rear dormer permitted development?

Frequently, within volume allowances and subject to the property not being in a Conservation Area, AONB or under an Article 4 direction — all of which are common in Cornwall. It is worth confirming rather than assuming.

Can a bungalow take a loft conversion?

Often, and it is one of the best-value moves available on Cornish bungalows, but the roof pitch has to be steep enough to give volume. Shallow-pitched post-war bungalow roofs usually need a new roof structure.

Do I need a structural engineer?

Yes, for any conversion involving new floor joists, steels or removal of trusses — which is nearly all of them. We coordinate that alongside the drawings so building control receives one consistent package.

Project type · Cornwall

Which loft conversion suits your Cornish house? Velux, dormer, hip-to-gable or mansard

Head height decides more loft conversions than budget does. Before comparing types, measure from the finished floor to the underside of the ridge: if you have under about 2.4m you are into structural alterations rather than a straightforward conversion, and the cheapest option stops being cheap.

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The four types, honestly compared

Each type buys usable floor area at a different price in cost, planning risk and external impact.

Rooflight (Velux) conversion — cheapest, lowest planning risk, works only where existing head height is already generous
Rear dormer — the workhorse: creates real standing space, usually permitted development at the rear, visually heavy if badly proportioned
Hip-to-gable — for hipped-roof semis and detacheds where the hip wastes the usable volume; often paired with a rear dormer
Mansard — most space, most cost, most planning scrutiny, and rarely appropriate on a Cornish terrace outside a townscape that already has them

Cornish roofs behave differently

Slate at a shallow pitch, wet-laid ridges, and older trussed roofs on 1960s–80s estates all change the answer. Trussed rafter roofs need the trusses removing and replaced with a new structural strategy — that is an engineered solution, not a carpentry decision, and it belongs on drawings before anyone starts cutting.

Stairs and fire are what actually fail

Two regulation points sink more loft schemes than the roof does: fitting a compliant staircase without destroying the floor below, and protecting the escape route so the new storey is legal. Getting the stair position right on the first-floor plan is the single most valuable half hour of the design.

Frequently asked

Straight answers.

How much head height do I actually need?: As a working rule you want around 2.4m from existing floor to the underside of the ridge before conversion, because floor and ceiling build-ups consume it. Less than that, and you are looking at lowering ceilings below or raising the roof, both of which change the project entirely.
Is a rear dormer permitted development?: Frequently, within volume allowances and subject to the property not being in a Conservation Area, AONB or under an Article 4 direction — all of which are common in Cornwall. It is worth confirming rather than assuming.
Can a bungalow take a loft conversion?: Often, and it is one of the best-value moves available on Cornish bungalows, but the roof pitch has to be steep enough to give volume. Shallow-pitched post-war bungalow roofs usually need a new roof structure.
Do I need a structural engineer?: Yes, for any conversion involving new floor joists, steels or removal of trusses — which is nearly all of them. We coordinate that alongside the drawings so building control receives one consistent package.

Not sure which loft conversion your house can take?

Send us a photo of the roof and the ridge height — we will tell you what is realistic.

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Tell us about your project — we usually reply within 2 hours (working day).