Some house loft conversions can fall within permitted-development rights, but the property type, previous alterations, roof enlargement, materials and location all matter. Flats and maisonettes do not benefit from the same householder rights.
Start with feasibility
Approximately 2.2 metres from the top of the ceiling joists to the underside of the ridge is a useful guide for a straightforward conversion. Lower roofs may require more substantial structural solutions.
Planning or Certificate of Lawfulness
Where a proposal is intended to be permitted development, a Certificate of Lawfulness provides formal evidence of that status. Other schemes need a planning application.
Building Regulations still apply
A habitable loft conversion requires Building Regulations consideration, including structure, stairs, fire safety, insulation, ventilation and sound.
What to send for an initial review
Provide the address, exterior and loft photographs, approximate ridge height and any existing plans or previous planning decisions.