Skip to content
BerkshireLoft Conversions

Suitability checker

Is my loft suitable for conversion?

Most lofts can be converted if there is enough head height (ideally 2.2m or more from the top of the ceiling joists to the underside of the ridge), a roof structure that can be adapted, and room for a staircase. Answer five quick questions below for a first view. It is a guide based on typical rules, not a survey: a specialist will confirm what your roof allows.

Last reviewed 22 September 2026. Based on our research into official and published sources, listed at the end of this page.

How much head height is there?

Measure from the top of the ceiling joists to the underside of the ridge, at the highest point.

Head height:aim for 2.2m or moreUnderside of ridgeTop of ceiling joists (the loft floor)
What does the roof structure look like?

Look along the loft: trussed rafters have diagonal timbers in a W shape.

Open space betweenrafters and joistsRidge board
Traditional rafters
Diagonal timbers in a W shape
Trussed rafters
What type of home is it?
What shape is the roof at the ends?

Hipped: the roof slopes down at the end. Gable: the end is a flat wall up to the ridge.

Is the home in a conservation area or listed?

How to measure your loft's head height

Stand in the loft at its highest point, usually under the ridge in the middle. Measure from the top of the ceiling joists you are standing on up to the underside of the ridge timber. Homebuilding & Renovating gives 2.2m as the typical minimum for a rooflight conversion. Below that, a dormer or hip-to-gable can create extra headroom, or the ceiling below can sometimes be lowered.

What happens next

If the checker says your loft is likely or possibly suitable, the next step is a survey. We can put you in touch with up to three local specialists, or you can estimate the cost first. Read the planning guide if your home is in a conservation area.

Frequently asked questions

How can I tell if my loft is suitable for conversion?

Check three things: head height (ideally 2.2m or more from the top of the ceiling joists to the underside of the ridge), the roof structure (traditional rafters are easier than W-shaped trussed rafters), and any planning restrictions such as a conservation area. A specialist survey will confirm it.

What lofts cannot be converted?

Very few lofts are impossible, but some are hard to justify: very low roofs (under about 2m) that would need raising, flats where the roof space belongs to the freeholder, and homes where there is nowhere to fit a staircase. Listed buildings and conservation areas add planning steps rather than ruling a conversion out.

What are the disadvantages of a loft conversion?

Cost, disruption during the build, the space the new staircase takes from the floor below, and the approvals involved (building regulations always, sometimes planning permission and party wall agreements). In lower-value areas it may not add as much value as it costs.

Sources

This guide is general information to help you plan. It is not legal or professional advice: check your own project with your council or a qualified professional.

Get free quotes from local specialists

Tell us about your project and we’ll pass it to up to three local loft conversion specialists.