As an architect, one quickly becomes aware of at least two sets of legal design constraints with which one must deal for building.
Zoning Ordinances = land planning. Updated by local City/County Councils as they see fit (you have some input as a community member... little, but some).
Building Codes = specific req'ts updated every 3 years, which most local Bldg Depts will utilize with regards to "Public safety, welfare, sanitation". Most local Bldg Depts will review new codes when they are published and offer local "Revised Amendments" for review (with input from local developers, builders, engineers, etc) prior to adoption. In our case (So. NV) these amendments must be passed by local gov't councils into law.
There are still a few places out in unincorporated Nevada (for example) where ya build something, then report to local County Assessor whatcha built for tax purposes. If it falls down and kills ya, it's your own fault. But those types of "free" zones are getting fewer and farther in between.
Light bulbs? Energy conservation. Same w/ windows.
That's the newest, latest, greatest, lemon freshened compliance code which local Bldg Depts utilize. I.E.C.C. (International Energy Conservation Code) accounts for openings in walls, insulation thickness, glass "U" values, light fixture/lamp types and quantities, heating/cooling systems.
Just try to build a real, honest to god, Abe Lincoln type log cabin in the city somewhere. HAH! Adobe? HUMPH! Curiously, we've designed several "straw bale" homes and while we had hell to pay at first, the energy conserving quality (when designed properly) has seen that alternate material move forward.
As Las Vegas has somewhat an international polyglot type of populace, I've gotten to work with builders, architects and engineers from Australia, China, U.K., India, Iran, Hungary, Czech Rep., Khazakistan (sp?), Brazil, Cuba, Japan, Israel and the Phillipines. None of them have, to date, such intense requirements for building as the US (well, maybe the U.K.), but they're trying hard to emulate our progress. (And still we have Hotels catch fire... lessons learned, code updates to be issued soon).
Here's a good one for ya... We now have to run some of our plans (commercial only at this time) by the local LE Agencies so they have a plan on file... just in case. Fire Dept has always had access (and design review) for obvious reasons.
If you know how to access it you can, thru the local assessors website, call up house plans for (recently built) "information purposes". Ya like that one, huh? Your house... on my computer screen (print out or save file, thank you very much). Everything is scanned into a computer. Everything!
MUAHAHAHAHA
Maybe it's good, maybe it's bad. All I know is, It is. Keeps me (and a lot of other people) busy. The next building code update is 2009. They've gotten quite a bit larger and more involved with each passing edition.