The combination of:

1. Land costs

2. Labor costs

3. Material costs

4. Zoning laws

5. Building codes

For example some zoning laws have a height restrictions, which limits my development to 3-story buildings, when I would actually want to build a 5-story building

For building codes, some would require me to put in $100 breakers, when I could do with simpler $20 breakers, etc. etc. for a LOT of items, which also feeds into the material costs.

If you want more specifics than that - open up your county/city website and start reading. It's not up to HN to do the legwork for you.

OK, but please don't post unsubstantive comments here.

Lots of people are specific, but it's a HUGE set of laws, and they're slightly different in different places. Like if someone says to you "supply restrictions due to single family zoning", someone else will say "Well Houston doesn't have that", but Houston allows you to sue your neighbor if they cast a shadow on your property, so it's a different method that gets to the same result.

Outside of a few Major cities, I’ve never seen these laws. Is it a boogie man? Where I live, the developers rule.

There is no city in the United States, large or small, aware these rules do not exist. Tell me what city, I’ll show you the code.