USI Building Solutions | 4,084 followers on LinkedIn. Local Knowledge, National Strength USI is a leading provider of installation and distribution services to the residential and commercial construction markets. We have over 1,700 employees throughout 46 locations across 16 states. The Company has two related business segments: Installation: Fiberglass, cellulose, and spray foam insulation; windows; mirrors; glass shower enclosures; closet shelving and storage systems; garage doors; gutters; fire stopping; and fireproofing Distribution: Insulation products and related accessories Our solutions are the backbone of residential and commercial projects coast to coast.