Staggered bungalow - rear dormer pd question

[choppertoo]

I've just bought a staggered bungalow (stupid design!!) it's offset by a metre on each half of the building am I able to build a dormer effectively in 2 halves under PD with each half being 20cm from the eaves of it's corresponding rear elevation (effectively a small dog leg) as usual the rules are clear as mud and I'm struggling to find any similar examples on the web. On the picture attached the grey area is what I believe the dormer should be like under PD rules. Essentially we originally wanted a full width dormer which would have been straight across following the line of the furthest eaves and the shorter half would be straddling a rear single storey extension slightly - planning have been a bit funny about this and we are currently in discussions with them and the architect and one of the proposals was to remove the dormer from the plans and do it under PD.