The building permit, approved plans, later plan versions, current photographs and authority message belong in one chronology. The contract, site diary and communications with the people carrying out the works can also help explain the actual progress.
Each alleged deviation should be described by component, plan status and photograph. The statement that the building is simply different is not enough for an organised response. The specific link shows which measure is meant and which document supports the comparison.
The document comparison is separate from the technical assessment. A planner can explain the execution from a technical perspective. The legal review additionally classifies the content, scope and consequences of the authority order.