In short, yes. As you are raising the roof ridge height (the point of the roof) then this by default requires planning permission. Don’t let this be a concern as we can handle the whole process for you. We can also advise on the probability of getting it through planning in the first instance, as we’ve had years of dealing with local authorities.
If you choose to do something more than just a roof lift, e.g. a rear dormer, then usually doesn’t add any additional delay or problems with getting planning permission. Again, this is somethign we can work with you and advise for your specific roofing renovation project.
For more detailed information about planning permission, please see Planning Permission page, which contains more details about planning permission and building regulations for a roof lift conversion in the UK