basically, what you need in btu for each unit can be calculated by multiplying the square footage of each unit by 3.5. i. e., a 1000 sq ft unit would need a 35,000 btu furnace at minumum. then you have to consider the distance from the furnace to the unit is services. if the building is a 3 story with a couple of apartments on the top floor, then those units should have at least 10,000 more btu than the calculation calls for. if each unit has the furnace within the apartment, then the calculation is what you go by. most systems are pretty much the same, but, just like a car, there are some brands that simply cost more to repair based on parts and such. trane seems to be among the most expensive. i recommend goodman. easy to install, easy to work on and parts are reasonable. no one can calculate the timing of repairs on any unit. i have seen 3 year old furnaces need work and i have seen some go for several years without an issue. too many variables to figure that out. if you are talking about having one unit for the entire building, same formula applies to the sq footage, however, i would not recommend this because inevibly, some apartments will not get as much heat as others, and with one furnace, you cannot control the heat going to each apartment. a boiler system could do that but if you don't already have one, it is going to be massively expensive to have one put in. in an inspection, look for the age of the furnace, this can be found in the model number in most furnaces. usually the 1st and second digits are the month it was build, and the 3rd and 4th is the year. however, this is not on all furnaces. basically, get the model number and look it up on line. anything over 15 years old is probably on its last leg and about as fuel efficient as a campfire. also, look for how clean the furnace is. if it is dirty, chances are it hasn't been service often enough. i would have it cleaned out at least once every 3 years at a minimum. change the filter at least once a month, especially in the winter months. a clogged filter not only can lead to premature damage to the heat exchanger, but will also effect the output and efficiency of the unit and could possibly poison your tenants with co2 gas. i hope this helps you, please let me know if you need any further assistance

So the square footage occupied by the fridge cost 1666 $ per ft.

When comparing two properties, both equal square footage, # of bathrooms, area.

I am going to be noting the square footage addition in the offer and will use it in the negotiation.

Here's the kicker- It's zoned for commercial use but grandfathered in as SFH-residential, however it cannot have its square footage increased without a costly variance from the City.

My husband and i have been burned by paying too much With the appraisal being MUCH less than what Zillow states...what i have done now-just to give me a ballpark, is look at the tax accessors numbers....we bought two properties in south Jackson and one appraised for 4000 less than the tax accessor office and the other (which had more square footage than what the tax accessor office has) appraised for 2000 more..both these houses were on the same street and about in the same shape...my husband and i paid 8000 for a 3 bed, 1 bath around 1100 sq ft.. granted it needed about 5000 worth of work, and my husband is a contractor.

For a single family rental, you won't have a choice of having some dependency on the tenant unless you end up paying for the required utilities to avoid issues with their not paying and then you lose footage/access as a result.I recommend talking to a consultant in your area to discuss what you want.

You could do it based on total square footage of the the house (Unit A is 1,000 sq feet, the total rentable house is 5,000 sq ft, so 1000/5000 = 20% to that unit, and so on)You cold allocate by the number of bedrooms.

Bedroom count was incorrect, sq footage wasn't correct, current rent being charged was 25% too low, a couple blatant physical issues that a couple thousand dollars fixed but probably turned some people off ect. 

I divide the gas and electricity among the 4 tenants based on sqare footage.