For any project to commence officially, the proposed design and drawings should be under the prevailing By-Laws and rules of concerned and local authorities. In context of Sri Lanka, the buildings drawings and maps are approved from Municipality level. Building Permits and Approval Hambantota
Once all the drawings and documentation are concluded, it needs to be submitted in concerned municipality for processing of permit and getting APPROVALS for construction. Taxes for approval varies from each municipality, which is charged on per sq. ft. basis. In any case if the design has to be changed, the changes should be approved by municipality. Building Permits and Approval Hambantota