Conversion of coal shed/outside toilet

[Rachael1976]

Good evening. We have submitted a lawfulness certificate to convert some outbuildings connected to the house which include an integral garage/stable type space and an outside toilet and coal store into a kitchen diner and utility. The planner is fine with the majority of the application but we have encountered an issue. The outside toilet/coal store is currently a sloping roof from heights point c. 2.5m ish which is the eves height of the main dwelling house down to about 2m. We want to raise one side of the roof to be 2.5 m to enable it to be a living/usable space once building control have had their way with damp proofing etc. Without increasing this height it’s unusable.

The planner is stating that we aren’t allowed to increase the eves height of the coal shed/toilet from its original height as part of class a and has stated that it does not form part of class b. Is this the case? Class A states “(d) the height of the eaves of the part of the dwellinghouse enlarged, improved or altered would exceed the height of the eaves of the existing dwellinghouse” does an outside toilet and coal shed form part of the dwelling house if its currently not habitable? Does Class B really not apply regarding alterations to a roof? Please can someone give me some advice - kindly. I’m quite new to this. Thanks