Agree.
I am interested to find out whether TRE Residences internal walls are "solid concrete" or dry walls.
Thus, not sure if this is correct.. but if TRE uses solid walls.. maybe (just maybe) it could be another reason why it is built slower or if it does not use pre-fab walls...
I agree with your logic. As another factor is progress payments. In large projects, each time a certain landmark is reached, buyers must fork out an additional amount of money. Thus this can be a huge sum for a developer especially if they had taken loans. Plus they need the money to pay the main contractors. No pay.. no fast work.. A vicious cycle: Main contractor needs to be paid early.. etc.. etc..
For HDB BTOs, it is based on common sense. HDB Toa Payoh Crest because of it's height.. took close to 5 years to complete. Where usually a "standard" BTO development often T.O.P. between 2 1/2 to 3 1/2 years depending on the size of the project. Majority of HDB BTO's are relatively between 500 units to 1200 max.