For example, if you are buying in an area that is in are 1980s and above, you might run into a roof that is tile and the paper under the tile needs to be replaced the day you close.

In some older neighborhoods especially historic districts, the tenants look for older houses - they preferred the art deco bathroom tiles, the thick plaster & lath walls over granite countertops and stainless steel appliances.but class D neighborhoods are easiest to tell. 

You good contertops and do a tile back splash with some color I think white subway is becoming a bit dated.  

(The floors are tile and terrazzo, so it is easy to clean up spilled paint.)We haven't gotten an estimate on the painting from a painter yet. 

Tiles people may slip in the bathroom right.

The couches and other furnature are outside on the porch, trash piled up, broken floor tiles and unkept yard. 

If not, the only requirement may be filing plans with the dept of buildings.One of our contractors does the bulk of his work on contracts with NYC.Mainly work related to bathrooms & tiles/flooring, I will shoot you a PM if I can get any information on this.All the best!

Quote from @Paul Gupta: Hi, in California, For jobs requiring a license, there was CSLB (contractor state licensing board) which would give either a General Contractor license, or specialty licenses by trade (~60 specialties such as concrete, welding tile, ) https://www.cslb.ca.gov/about_us/library/licensing_classific...My Q: does Maryland and DC area have similar requirements? 

I like good neighborhoods, with sloped tile roofs, stucco siding, built in the last 20 years. 90% of Las Vegas SMF checks none of these boxes. 

Quote from @Stuart Udis: Jay noted some good upgrades.Bathrooms: I spend more on tile across the board but even more so on for sale housing.