Loft conversion + 1st Floor extension (Roof addition)

We are looking at a project for a loft conversion plus building a 1st floor extension over an existing ground floor extension.

The loft would be a hip to gable that would be covered under PD.

Planning is required to build the first floor extension. This would include a new roof that would be accessed from the exiting main roof.

Question is is it worth submitting two separate applications. PD & PP or would this cause potential issues.

The easiest thing would be to stick it all in as a PP but a little concerned the hop to gable element could then be refused....even though logically they shouldn't if it could be done under PD right?

It would depend on your LPA’s Planning policies. If loft extensions/conversions with or without dormers are generally frowned upon, then utilise your PD rights. You’d have to carry out and complete the PD works before applying for formal Planning. PD cannot be used on the first floor extension.

The above would only be true if we new in advance that PD rights would be curtailed as a condition of commencement.

I would say the hip to gable element has the potential to be refused as it 'unbalances' the pair of semi's

It would seem to me as DevilDamo stated the safest bet would be to literally construct the hip to gable under PDS then submit planning for the first floor extension with additional roof space.

Its then just a matter of the extra time this process takes...