We have moderate mold in the crawlspace of our home. We contacted 2 companies to remediate this problem.

One company recommends installing a "clean space", which seals all air vents and installs sumppump to keep out moisture. They say it is not necessary to treat the existing mold . That it dies when humidity <70%. Treatment with biocide is optional. They said we could have the insulation removed and not replaced since the "clean space" is sealed and acts as insulation for the house. We live in central Virginia. Is this allowed by building code?

The other company recommends removal/replacement of all the insulation. HEPA cleaning of surfaces, installation of vapor barrier on the floor of the crawl space and part way up the walls, treatment with biocide, installation of ventilation system that pulls air from inside the house through the crawl space. Their theory is to increase ventilation and the first company wants to seal the crawls space.

Which is the best approach? Both cost about the same.