Hi roamca,
perhaps u can check with the existing owner if they are actually moving out early, if so, probably you could get ur ID to arrange an idemnity form from HDB between you and the existing home owner to proceed with the reno even earlier den the handover date...? Used to handle a few such cases before for some clients, but of cos the existing owner has to agree.
3 days approval hacking in most circumstances, would be for general hack of floor and wall tiles as such, however, if you gonna hack down walls and etc, it would require 2 weeks or more, depending on the HDB officer and whether you require a PE endorsement.
Hope it helps...
