In a year in which green products captured attention throughout the residential marketplace, no area of the Top 100 was more zeroed-in on sustainability than the construction and building materials category. Readers clamored for information on products that improve the building envelope as well as for efficient HVAC units.

Insulation in particular garnered attention, capturing five spots on this year's list, led by Knauf's EcoBatt (No. 2), a product boasting recycled content and an energy-saving production process. Spray-foam options (Nos. 5, 6, 13) continue to attract interest for their high R-values and confidence-building coverage.

Efficient water heating again dominated the ranks, but what once landed on our list for their newness and curiosity factor has now become a sought-after ware for homes undergoing green building certification or applying for tax credits. Options abound, from tankless units (No. 80) to solar thermal (No. 57) to two "hybrid" products (Nos. 4, 26) that combine the benefits of tank and tankless units. High-efficiency heating systems (Nos. 27, 96) also made the list.

Rounding out the Top 100 is Vantage's energy-management tool (No. 100), a category that is growing rapidly as builders recognize the benefits of monitoring systems that can alter homeowner behavior for the benefit of the planet and their bottom line.

And the sustainability doesn't stop there. A number of other construction products in this year's Top 100 contribute to high-performance homes that last long, operate efficiently, and provide for a more comfortable interior environment. With many adding little or no cost to a traditional home, there's never been a better time to go green. --Katy Tomasulo

#5 Fomo Products. Handi-Foam Sound Barrier spray-foam insulation achieves a Sound Transmission Class rating of 35 at 3 inches thick. The low-density, open-cell foam is designed to cover and fill large voids and surfaces. It cures in 30 to 45 seconds and, based on kit size, yields up to 1,350 board feet. The kits include a Handi-Gun, so no additional tools are needed. 800-321-5585. www.fomo.com.

#2 Knauf. EcoBatt fiberglass insulation utilizes Ecose technology, which converts natural organic materials into an inert polymer, binding the insulation fibers; the technology, which is up to 70 percent less energy intensive than traditional binders, allows for the same performance but greater sustainability, says the firm. The insulation contains no formaldehyde, acrylics, or artificial colors. It contains a minimum of 30 percent post-consumer recycled glass. 800-825-4434. www.knaufusa.com.

#13 Icynene. The company's LD-R-50 spray-foam insulation has earned the U.S. Department of Agriculture's BioPreferred status for use of rapidly renewable materials. The insulation is made using castor oil, a natural product that is extracted from the castor plant. The product is water-blown and free of HCFCs and PBDEs. 800-758-7325. www.icynene.com.

#15 iLevel by Weyerhaeuser. Incorporating the maker's Shear Brace, TimberStrand LSL beam, and a proprietary portal connection, the iLevel Garage Portal System offers increased lateral resistance compared with traditional site-built garage fronts, the maker says. The braces have pre-drilled chases and holes for wiring and garage lights, and additional holes can be drilled. 888-453-8358. www.ilevel.com.

#17 ECR. The Freewatt Energy Star-rated home heating system combines a high-efficiency natural gas furnace or boiler with a Honda generator. Electricity generated from the system can power a home or be sold back to the grid. The savings created by using Freewatt for one year is equal to not driving your car for six months, the maker says. 877-386-5475. www.freewatt.com.

#25 LiteSteel Technologies. Made from cold-formed, lightweight steel, LiteSteel Beams (LSB) combine the strength of steel with the workability normally associated with wood beams and headers. The LSB design incorporates two fully welded hollow flanges and a flat, thin web that combine for maximum structural performance and load-carrying capacity. Suitable as basement, garage, roof, and ridge beams; long-span headers; and floor and deck supports, LSB weighs only 7.5 pounds per linear foot and can be cut to length on the jobsite with a circular saw, and drilled, screwed, bolted, and nailed using standard professional tools. It is available in 12 sizes ranging in nominal beam depth from 8 to 14 inches. 877-285-2607. www.litesteelbeam.com.

#100 Vantage Controls. The company's energy management system provides real-time information on home energy usage; it also can provide recommendations on ways to reduce energy use and can predict how much money homeowners will save if they implement the strategies. For example, the system can estimate how much money a home will save by setting the house to use occupancy sensors. 800-555-9891. www.vantagecontrols.com.

#26 Grand Hall. The Eternal GU32 hybrid water heating system combines the best attributes of tank and tankless systems, the firm says, with an inverted-infrared heat burner that uses thermal activation like a tank and flow activation like a tankless. The system uses a counter-flow design and multi-pass heat exchanger technology to maintain an 86 percent thermal efficiency rating with consistent pressure. The unit operates at a lower emission rate than traditional tank and tankless water heaters, says the company, and its nitrogen oxide emission is less than 5 parts per million. 877-934-7455. www.eternalwaterheater.com.

#27 Trane. The EarthWise dual-fuel split system lets homeowners use electric or gas heating, depending on annual energy trends and fuel prices. The heat pump is Energy Star qualified, and the furnace exceeds minimum government efficiency ratings by almost 20 percent, the maker says, adding that the EarthWise split system can save up to 40 percent on energy bills. 800-235-2152. www.trane.com.

#28 Viega. The company now offers Mixing Stations in six upgraded base configurations. Features include low- or high-head, three-speed circulators, new sensor wells, and new ball valves. The Mixing Stations can be used in conjunction with a range of heat sources, including boilers, water heaters, and geothermal heat pumps. 316-425-7400. www.viega.com.

#57 Rheem. Designed to simplify installation, the SolPak all-inclusive active solar domestic water heating system comes with a heat exchanger tank, solar collector panels, a controller, multi-speed pump, thermal expansion tank, and other items. Collector panels are certified by the Solar Rating & Certification Corp. The maker says a SolPak system can reduce the water heating portion of energy bills by as much as 80 percent. 800-621-5622. www.rheem.com.

#45 Superior Polymer Products. Designed for furring-out block or poured concrete walls, the EcoStud provides a thermal break when attached directly to exterior concrete or block. Made with recycled resin, the stud will not rot, rust, corrode, or support mold growth or termites, says the firm. It can be used with all forms of insulation. 877-586-5543. www.superiorpolymer.com.

#55 Green Glue. The noiseproofing system consists of four components: noiseproofing compound, clips, sealant, and joist tape. The compound goes between sheets of drywall or other substrates to convert sound vibration into small amounts of heat; the clips allow each side of the wall to vibrate independently; the sealant plugs gaps; and the tape helps eliminate squeaky floors. The system can block 97 percent of noise, the company says. 866-435-8893. www.greengluecompany.com.

#63 CertainTeed. The T-Roc Thermal Laminate Foundation Insulation System, comprised of GlasRoc paperless gypsum board permanently laminated to expanded polystyrene insulation, allows for faster insulating and finishing of below-grade concrete walls by installing easily in conventional concrete wall forms and eliminating the need for stud frame-out, batt insulation, and drywall, says the firm; after the concrete is set, the wall forms are removed and the basement walls are ready for final finishing. A 1?1/2-inch electrical chase runs vertically through each panel. GlasRoc gypsum board features reinforcing glass mats embedded in a water-resistant core; the foam is treated with Perform Guard to protect the panels against termites. 800-233-8990. www.certainteed.com.

#89 NuHeat. Homeowners can easily control Nuheat floor-warming systems with the Energy Star-rated Solo programmable thermostat. The dual-voltage unit features seven-day programmability and can link to other heating zones within the home and to external temperature sensors for one-stop temperature and information control. A simple three-button design, full menu screen, and Web-based tutorial make programming easy. 800-778-9276. www.nuheat.com.

#96 Mitsubishi Electric. Mr. Slim M-Series heat pump systems qualify for an Energy Star Tier 2 rating, measuring 22 or 25 SEER, up to 75 percent better than the industry standard of 13 SEER, the maker says. Even at 17 degrees F, the MSZ-FD models produce up to 13,600 BTU/h of heat, says the company. No ductwork is required at installation, and the product includes zone control to cool and heat only desired spaces. 800-687-1966. www.mehvac.com.