Zoning and construction laws dictate designs and limitations on your home.
Lg_mouth, you apparently live outside city limits or in a rural area. In cities and towns there are often regulations on the design and construction of a residence. These can be very general to specific. In a city, they may dictate that in certain districts your new construction OR remodeling does not vary signficantly from existing designs...this is often done around "historical" areas like those with Victorian era homes. Outside of that area, you are less restricted on the design or "look" of your house.
Townhome and condo complexes are very tight on what you can do to the exteriors. Mostly because the associations are generally responsible for exterior maintenance (walls, roofs, gutters, paint, etc.).
Toybox - It's not just a matter of looking before you buy, but watching the attempts to sneak in draconian building requirements after the fact.
In a city nearby they inproved the standards for new-construction homes over the existing (1960's) homes. Friends bought a house there and had it partially destroyed by a fire. He had enough insurance, until he found out new building codes increased the expense (more insulation, mandated dual-pane windows, new 'quake anchoring, new plumbing materials, etc.). He found a way around most of it, but it was still expensive.
You're going to see a move away from incandescent bulbs spreading across the country. The merits of such a thing are debatable.
I also agree that building inspectors can nit pick about things just for the sake of their little bureaucrat's handbook. A friend in construction says they can be the most petty-minded of bureaucrats and half of 'em are fishing for some kind of "gratuity"