I'm trying to help my Sister & her Husband solve this issue that's been plaguing them.  Any advice or recommendations for a specialist would be greatly appreciate. (They are in W. Bloomfield, MI)   Here's her narrative below:

The home was purchased in 2016 and all the carpet and wall paper was removed. The house was completely painted with both latex and oil based paint. New engineered floating hardwood floors were installed over the slab and other hardwood floors were sanded and restrained before moving in. Basement was gutted and drywall and ceiling tiles were added and painted.

The garage had a strange odor and the floor was sticky from old carpet so the floors were epoxy painted. New recessed lights and electrical work too. .Due to smells in the garage not going away, the drywall on the 3 walls was removed and the garage was then insulated with cellulose insulation , drywalled again and painted. The ceiling beams was spray painted black.

There was an odor still coming into the house so it was suggested that we had a rodent issues and to remove all the old fiberglass insulation in the attic and put cellulose which is coated in borax to deter animals and help insulate the house. They also spray foamed in the basement.

My husband was having a sensitivity in the basement and garage where his skin was itchy prickly so he removed the new ceiling tile and new carpet that was off gassing but it didn’t help.

After the cellulose was installed, he started having breathing problems and felt as if the house was too tight. So he started having tests done to test the levels, he did mold testing, water tests, blower door tests, carbon dioxide tests, and after all the tests it was suggested by a few air quality people to add ventilation that maybe the house was too tight . Then an ERV was installed but it was oversized for the house so it didn’t run all the time. He also blasted ozone at one point. We also rented air scrubbers.

It wasn’t until after I had the baby that I started having chemical sensitivity , I was in the house 24/7 for 3 months. I always felt like the house was dry but the humidity meter showed it was fine.

My husband then changed out all the recessed lights to airtight lights and on a few of them they used fire safe caulk. We also turned on the a/c and there was a leak last year but they couldn’t find it in the line.

After a 4-day visit out-of-town, I felt burning in my mouth, nose, when I breathed.

We left the house. Now when you walk it there is a very strong chemical smell and we can’t pinpoint what it is. The a/c company has come out several times, we are running the a/c constantly to see if the dye they put in will show a leak. The chemical smell burns your nose and when you breath.

The ERV has been removed and and a clean air intake installed that is supposed to bring fresh air into the house.

Today consumers energy come out to look for gas leak, none. But she noticed the chemical smell.

Help ☹️