Hi Edifice,
I estimated TM's GFA based on the dropbox info available here:
www.skyscrapercity.com/showthread.php?t=1500584&page=13
- look at Queenbourke's posting.
The floor plan at the dropbox link shows a total of 490+ units. 70+ units were missing, which I found comes from one whole side on the 16th-31st floors. I added up the 490+ units' individual sizes and arrived at 336,750 sq ft. Since the missing 70+ units is on the side which are mainly made up of smaller units, I then estimated they may add up to a figure that brings total GFA to 380,000 sq ft. I am assuming $0 value for retail space for conservative reason, just in case I overestimate the GFA for the residential units. I also remember there were penthouses (which would be larger in area), but to be conservative, I am ignoring this.
Thanks for pointing out car park space; you are probably correct, and owners may have to pay for car park lots. This will certainly boost the gross sales proceeds and profits. It's good that we share info and ideas since sometimes we do forget this and that.
Greenrookie, sometimes I call agents up to see when certain projects are due for launch, launch prices, sales figures, etc. Sometimes they send me links to floor plans, etc. Sales figures can be gotten from visiting showflats as well as URA's website. My Manhattan's latest figure is from URA's site for eg, where you can see 288 units are sold to date, out of 301.
RNAV calculation: this is the tricky one as various assumptions are used. I would say as long as I use conservative estimates here and there, I would not expect to err too much on the aggressive side. For an unsold project, for eg, I would take total estimated sales value, minus total estimated costs, minus taxes, then use a discount method if I wish. To simplify things, sometimes, I drop the discounting but instead make lower estimates on selling prices and GFA (unless I know the exact figures), higher costs, etc, as it is difficult to know exactly how many months to discount a profit (since many projects TOP way earlier than earlier estimates).