BestMaterials.com
The building supplies discount warehouse, offering a huge variety construction tools and materials at excellent prices.

BuilderCentral.com
The leading building industry directory designed to help you find home builder, home improvement, contractor and more.

Discover Solar Energy, a helpful portal to relevant renewable energy websites of individuals, governments and organizations. The links are cross-referenced to help homeowners, engineers, hobbyists, teachers and students find quick answers to issues relating to alternative energy.

Horizon Energy Systems -
Conserving energy today ... for tomorrow, with innovative green building products.

RoofersCoffeeShop.com
Portal site for roofers, including lots of helpful links, information, forums, interactivity, fun, etc.

Sweets.construction.com
Huge directory of products and information, with several communities serving all aspects of the construction industry.

Roof Estimating Tools:

Roofing Calculator - this tool helps calculate the cost to install a new roof on a building of any size and complexity. Calculations are provided for conventional roofs including asphalt shingle, cedar shake, slate, Spanish tiles, and metal roofs of all types including interlocking shingle and standing seam.