Loft conversion advice for maisonettes

[Northanger1]

Hi all

I'm considering a loft conversion in my first floor maisonette (semi detached property). I share the freehold with the downstairs owners.

Before I start spending on architects, planning application etc, I'd like to know how big a conversion I'd be allowed. If I can't do a hip to gable conversion, big enough to fit in a bedroom and ensuite - it probably wouldn't be worth the cost to me.

An architect told me informally that as a maisonette we'd only be allowed half the volume that our neighbours have next door (their semi hasn't been converted to a maisonette), but that sounds illogical to me. Surely our local planners should want it to look similar to next door's for consistency.

I'm really struggling to find any guidance online though, and my local planning authority just want to direct me to their chargeable pre application advice service.

Does anyone have any info on what's allowed for maisonettes/flats? The info on the Planning Portal seems woefully vague!

Thanks.

 

[^woody^]

As it's a loft conversion, the size allowed is however big the loft is!

Dormer size will depend on design and how it looks.

Choose a different Architect when the time comes.

 

[Nakajo]

It probably has little bearing in this instance, but note that a house has PD rights whereas a maisonette does not. It is sometimes the case that more development is achievable under PD than would likely be granted under a planning application - regardless of the aesthetic merits.