What is labour work ? Need to give more details.

No idea how you can say that without any breakdown description of type of labour, quality of workmanship, quantity of material, installation details, etc

Better talk about the weather and rain .. same context..

Either yourself or contractor must have a dimension layout plan of your structure and external line of the 3ph electricity source.

1. The electrical contractor must then indicate on that layout plan the route of the existing 1ph and new 3ph wiring from source to your electrical db.

2. All electrical lighting pts, sockets and main electrical appliances must be indicated on the layout plan.

3. The existing and new wiring path shown on the layout plan.
Highlight new wiring line indicating cable size, ug/high level run from db to pt.

4. Do a quotation base on this drawing for the bill of materials, supply/install/transport/storage applicable labour and authority submission/follow-up/approval. Make good any damages during works or to client's acceptance.

5. Testing and commissioning.

6. Agreement to the quotation based on bill of qty i.e contractor owner payment schedule and period of completion

Use this guide line so the contractor can inform you and no arguments on scope of works.