You are doing it differently than the development plan requires. That would be a technical solution that argumentatively justifies the exemption from the stipulations of the development plan. If it says you are only allowed 1 m, then you are only allowed 1 m - period. Everything else must be exempted / approved. When the development plan was drawn up, there was a reason why only 1 m is exempt from approval. Take the construction expert's advice and go to your building authority, they will surely help you, if not: submit an exemption application, then the municipality / city council must decide whether it is justifiable - if they reject it, you can complain to the building supervisory authority (district office) and file an objection, they can replace or confirm the municipality's / city council's decision.