When you give someone an inch, it's very difficult to take it back.

Replacing all light fixtures, faucets, doors, door knobs, ceiling fans, every inch of wall was repainted, all moulding from brown to white, new laminate flooring through the whole first floor and vinyl in the bathrooms, repainted the deck, and really landscaped outside, as well as a brand new porch.

Hopefully if you thought you were within inches of the starting line you now see you should take a little more time to look around and gain some more knowledge.  

Now the short answer is, unless you clean every square inch the property is still contaminated.

If you have the money, i would do that plus add a metal z channel going opposite direction of the joists ( screwed on top of the existing plaster ) and then add another layer of drywall. the Z channel leaves a space that helps in sound transmission. the problem is the sound is transmitted through the existing floor joists too, so just the insulation will not do it because the joists are still against the ceiling. this is something similar, but in this picture they used clips in combination to hold off hat channel from the existing ceiling which will lower your ceiling about another inch. 

Professionals drill (two feet or the longest masonry bit available) into the hole every 24 inches around the exterior and interior (if the basement is not finished) perimeter of the building and spray the chemical into the hole.After you have sprayed the chemical in the hole patch the hole with cement so the rain doesn't flush the chemical out.

Roof, all plumbing, all electric, all HVAC, all gas lines, adding bathroom, moving walls, all windows, huge deck addition, drywall every square inch.

I've been using Utilitech Pro fixtures in 3500K.I use the 12.6 inch ones in hallways and closets.

If you give a few inches soon they take a mile. 

While others are "Cars have to be within 5.25 inches of the yellow parking line designating your parking space".I have a feeling if they have that in their Bylaws or rules you are going to have a difficult time getting it changed.