Garden Site Infill House Garden Separation

I have the forms AP1 and TP1 ready to use
My aim is to separate the garden site at this stage - transferring the garden site into my name and my sons name
*****
The infill house is partially built but has not yet received a Certificate of Completion from my local Council
Can I proceed with the separation as the build has started.?
This was done to keep within the Planning Permission timescale
Many thanks...Barbara

Barbara - there is no direct link between the planning/building process and the registration. None of the former impact on the latter re timing and more. It's all land irrespective of whether you plan to build, have started to build of have built.