Local authorities usually employ building inspectors. 

He inspect and approve the work at the completion of each of the following stages and before the next stage begins: 

1. notification of commencement of work

2. on completion of excavation for foundations

3. after the foundations have been laid

4. at damp proof course level

5. at concrete or other material laid over site stage

6. drains and sewer completion

7. back fill of drains and sewers

8. installation of all services and before 1st fix plaster

9. completion of work.