Chelsea Building Products designed The TrustGard System, for today's consumer.  In 1975 Chelsea Building Products was the designer of the nations first tilt-in vinyl. Since then Chelsea has been one of the country's premier designer and extruder of vinyl window & door systems. 

The National Fenestration Rating Council, NFRC, is an independent
third party organization which sets testing criteria for the window and door industry.  Since 1999, National Vinyl Product, Inc. has certified all it's manufactured products under the NFRC guidelines.