What surveys do you need for a barn conversion?

Structural survey

This is the most important survey. A structural engineer checks the walls, roof, frame and foundations, and says whether the building can be converted without effectively rebuilding it. For a Class Q scheme this is essential, because the building must be capable of conversion. Do it before you buy or commit.

Bats

Old barns often have bats, and all bat species and their roosts are protected by law.

• A preliminary roost assessment can be done at almost any time of year. It looks for signs of bats and rates the building's potential.
• If more surveys are needed, emergence and re-entry surveys can only be done in the bat active season, roughly May to September. More potential means more visits.
• If the work would affect a roost, a protected species licence from Natural England is needed before work starts.

Because of the season, a late preliminary assessment can push the whole project back by most of a year. Book it early.

Nesting birds and other wildlife

Active birds' nests are protected, and barn owls and swallows often use barns. Work that could disturb nests is usually planned outside the main nesting season, roughly March to August. An ecologist may also look for other protected species, depending on the site.

Flood risk

Barns near the River Taw, Torridge or other watercourses may be in a flood zone. A flood risk assessment may be needed, and it can affect the design, such as floor levels.

Contamination

Farm buildings may have stored fuel, chemicals or asbestos. An asbestos survey is important before any work, and contamination is one of the matters the council considers for Class Q.

Drainage and services

Many rural barns have no mains drainage. A percolation test shows whether a soakaway or drainage field will work for a treatment plant. It is also worth checking early how far away water and electricity connections are, as long runs add cost.

Biodiversity net gain

Permitted development, including Class Q, is exempt from biodiversity net gain. Since August 2026, planning applications on sites of 0.2 hectares or less are also exempt, which covers most single barn conversions. Larger sites may need a net gain plan.

Planning a conversion?

We can organise the surveys in the right order, then handle planning or Class Q and the build. See barn conversions, and our pages for Great Torrington, South Molton and Barnstaple.