In Singapore, all building works will require a building plan approval. Building plans are to be submitted by a Qualified Person. A Qualified Person is a person who is registered as an Architect or a Professional Engineer and has in force a practising certificate issued under the Architects Act or the Professional Engineers Act respectively. An approval should be submission before you intend to commence work.
It is an offence to carry out building works if the plans have not been approved and a permit to carry out building works that has not been granted by the Authorities.
In addition, you may need to obtain planning permission from the Urban Redevelopment Authority (URA) before plans could be approved, and obtain a provisional planning permission before a permit to carry out building works could be granted by the Building Authority.
Also, there’s a need to obtain Fire Safety Certificate (FSC) from Singapore Civil Defence Force (SCDF) before occupying or using the premises. The FSC is only issued after full completion of all fire safety works in the project. Failure to comply with this is an offence under the Fire Safety Act and the owner is liable to court action.