i have heard the rule of thumb is 10k per floor...

You could take the difference between the maintenances and calculate from that. That'd tell you how the sponsor valued the apartments when divvying up the shares and selling to the insiders.

E.g., I have 744 shares and the increment is 4 shares per floor. If I could get $1M, say, then the differential would be $5.3K per floor. Assuming same condition, all on the market at once, etc.

Sometimes, though, that increment in shares from floor to floor doesn't reflect something like a view opening up once you hit floor x, for instance.

I think NWT's approach is worth calculating, but it is only a starting point. The $10K/floor is another point to work off of. But truth is, in a tower, the 27 and 32 floors are pretty much identicial so the $10K/floor is not a hard and fast rule. In the 5th floor versus 10th floor example, I'd say the 10th floor is meaningfully higher simply in terms of noise alone. If views improve and light improves, then the $10K/floor seems a good formula. Certainly no more than $50K for the floor differential.

One another calculation I have seen is 1-1.5% additional per floor. As Kyle said, though, you must get something for the additioanl cost which is why 5-10 is a more meaning ful than 27-32.

my broker told me rule of thumb $15k per floor if no significant difference in light/view, otherwise $25k, for whatever its worth.

I must admit, I think the size of the apartment becomes a larger part of the equation, than is taken into account with a more simple fixed price per floor, which is why I prefer the % of apt value method. IE with a studio such a small area is effected being on a lower floor, however with a 3- 4 bedroom it is a totally different matter to get less light, more noise and less prestige in an apt.

Real life example, new construction, sold/closed same week...over $50k premium per floor. For New construction, $50k+ per floor is the norm...just look at any new building and you can see this is true

101 West 24th St, 4A
Sold on May 21, 2008 for $959,000
Manhattan, NY 10011
Single Residential Condo Unit

Zoning: Boro-block-lot: 1-800-1303

101 West 24th St, 9A
Sold on May 29, 2008 for $1,250,000
101 West 24th St, 9A
Manhattan, NY 10011
Single Residential Condo Unit

Zoning:
Boro-block-lot: 1-800-1308

signifcance in terms of the change in quality of view/light must be taken into account. So I agree with kylewest and account for this in my analysis for clients.

if 5th floor doesnt clear building, but 113th floor does by a good margin, 10K/floor is not enough to account for difference in light/view, I would up to 20-25K per floor in those cases. When there is no major difference, usually 10-12K a floor is a good formula. In prime streets, like Msdison/5th, up that to about 30-40K a floor sometimes as money will pay big time for park views if they get it!