I get this question a lot and I need help from you!
Why are drive-thru coffee stands so popular in the NW, but hardly found elsewhere in US? Yes, I do know they are popping up elsewhere, but they have a long way to go to catch up. No, really, if you've never been in the NW, you probably think I'm exaggerating, but they are everywhere!
One theory I've heard is that the little buildings get very hot from the espresso machine and require air conditioning in the summer months... except in the NW where the summers never really get that hot. (Especially this year!) I don't really buy that theory. Air conditioning a tiny building couldn't be that expensive. What do you think? Let me know what state you live in, if you reply.
With a previous employer of mine, we would help put people into DDT buildings throughout the country. In each region of the country, I have seen various results and various guidelines for planning and zoning.
When it comes down to it, I think it is a matter of start up cost. In the northwest where there are a lot of DDTs, the planning and zoning, and landlords, are used to this style of building and have systems in place for getting them in business efficiently and effectively, since they really are everywhere. Many of times in other places such as the Midwest, they have much stricter guidelines, that are meant to act as blanket policies for ALL buildings. Majority of the newer buildings in the Midwest are required to be ADA compliant, hard plumbed, and meet guidelines of new larger retail buildings/centers in the same commercial district (differs per municipality). Aside from that, if the particular site does not have utilities already run to the PAD site, then there is a very hefty additional cost. I have seen one particular site rack up $100,000 in site improvements alone. Many times the landlord will incur this cost in exchange for a long lease term and will amortize and build the tenant improvement monies into the lease (not always tho). You take that additional cost/term and add ~$75,000-100,000 for the small fully compliant building and equipment, you may be looking at upwards of a $2,000/mo note payment plus a $1000+ PAD rent payment making it harder and harder to break even. There are very few start up DDT's that can maintain that financially.
As Steven said, I don't think the AC is going to break the bank. I truly think it is the initial start up cost that will break the bank.