We have always used a ‘rule of thumb’ in my authority that converting two residential units to one does not constitute development however the loss of two or more units would require permission. This is also considered as a cumulative loss, i.e. if three units had been converted into two in the past (without needing permission) and then it was proposed that the two units be converted to a single dwelling, this second development would require permission as cumulatively two units would have been lost. I am aware that case law has suggested that each situation must be assessed on its own merits and the impacts of the development assessed in the context of local development policies (i.e. there may be policies which resist the net loss of residential units). This however makes formulating a consistent approach to deal with for example pre-application enquiries, or enforcement cases, extremely difficult. Does anyone else have experience of this issue and could advise of their authorities stance and any useful case law? Many thanks.
