We purchased a large home with a disastrous crawlspace: moldy, wet, falling insulation, rodents, etc. Indoor Environmental Systems did a very thorough on site assessment and gave us an estimate for a total makeover. They were very specific about the scope of the work and discussed in detail the benefits of crawl space vapor sealing and attic sealing. We had not planned on investing so much money in what was originally going to be a cleanup of the crawlspace, but after doing our research we were convinced that the energy efficiency we would gain would be tremendous. They did a meticulous job on the 3000 square foot crawl space, spending many 100 degree days underneath the house. We uncovered some foundation issues and they came back later to help clean up after the repairs at no charge. They discovered critical problems in the air system flex ducts which we also subsequently had repaired. The work was very professional. Great team, careful work, and excellent follow-up throughout. The air in the home is now as clean as can be. We highly recommend their services!