I created my own Google sheet for building efficiency per tile, and yes, I calculate both per core tile, and per core tile plus half short size to adjust for the street needed.
The trickiest part which I am still playing around, is what coefficients to use for attack/defense/units/fp/goods (do not care about anything else). Special abilities are just placed in the 'notes' column.
For my own comparisons, I started by benchmarking the "most efficient for the stat" spammable building as "100%" for each stat. And then modified some of them that I felt were over and underrepresented from there.
i.e. Sentinel Outpost at 4% per tile gave defense/tile a multiplier of 0.25. But getting a lot of L2 sentinel outposts to cover all your defense is quite difficult, and none of the other sources came close to that, so I gave it an additional 50% more (0.375).
My current coefficients:
FP : 1.42 (based off Helter Skelter Wheel of Death spam *shudder* - but there are fall field layouts optimized around begonias that are close)
Treasury Goods : 0.15 (based off Great Elephant: Elephant's Bazaar)
Goods : 0.37 (based off Pergola Pizzeria in SAJM - used to be 0.47 based off Sleigh Builder if looking at lower ages or only wanting current age)
Troops: 2.50 (based off Knight's Pavillion)
Attack: 0.70 (based off Winner's Plaza L2 in SAJM - Fall Fields layouts are close to the same in all ages)
Defense: 0.38 (based off L2 sentinel outpost + 50% premium for being difficult to collect as much as one might want of them)
I do also have coefficients for less desirable stats in my ranking, but typically give them a hefty penalty (often dividing by 4 to 10) to represent "this doesn't have *zero* value, but it's not really something to prize either in a main city). i.e. diamonds (because you could instead make them in another world), coins & supplies & their boosts (because usually you should have more than enough in most strategies)