We are Lockport's #1 home exterior experts! Roofing, Siding, Windows, Gutters, Doors: We perform high-quality home exterior work at reasonable rates. A+ BBB. DNS Exterior Inc. is a full-service contractor. We don’t just provide our customers with the choices that will best fit their needs and budget, but we also offer the installation of the products by our factory trained and certified installers. We are best known for our expertise with exterior products such as windows, siding, roofing, soffit/fascia, and gutters.