Daylighting serves several green purposes. Studies show that natural daylighting can improve the general well-being of building occupants as well as provide such measurable benefits as increased workplace productivity and enhanced school performance. The energy benefit from daylighting generally comes from both savings in electric lighting and cooling-load avoidance.

As with other building products made from wood, the source of that wood should be an important consideration. However, energy performance is the primary green consideration of windows, and new developments in window technology enable today's products to far outperform those of a few decades ago. Among the improvements are multiple glazing layers, low-conductivity gas fills, better seals on insulated glazing units, heat-reflective (low-emissivity) coatings, advanced weather-stripping, and new frame systems. Low-emissivity coatings which allow short-wavelength solar radiation (sunlight) to pass through but reflect long-wavelength radiation (heat) back into the conditioned space are now standard options from all major window manufacturers. Further improvement in energy performance is achieved with triple-glazing and multiple low-e coatings; sometimes an additional glazing layer is provided as a suspended polyester film.

Composite windows come in two basic types: fiberglass, and wood/plastic composite. Fiberglass has some distinct advantages over wood, vinyl, and metal for window frame and sash construction. As high-quality wood resources become scarce, fiberglass (a composite of polyester resin and glass fibers) is likely to become more common because of its energy performance and durability. Pultruded fiberglass frame members have a hollow profile that's usually insulated with fiberglass or polyurethane foam. Because the conduction through window frames is a significant source of heat loss, insulated fiberglass frames are an attractive option. The coefficient of thermal expansion of fiberglass is low, very similar to that of glass; limited differential expansion and contraction between the sash and glazing materials puts less stress on the glazing's edge seals. Durability of fiberglass as an exterior material is also good. Most fiberglass windows have factory-applied, baked-on coatings and can be repainted.

Active skylighting systems rely on reflectors and sun-tracking mechanisms to increase daylight entry; these systems boost daylighting primarily during early-morning and late-afternoon hours when the sun is low and little direct sunlight typically enters a conventional skylight. Another technology, prismatic skylights, refracts sunlight to boost daylighting performance.

Shades, blinds, and other window treatments can control daylight penetration and significantly reduce heat loss or heat gain through windows. Insulating window blinds and quilts may be appropriate retrofits for older, leaky windows, when window replacement can't be justified. In new construction or when replacement can be justified, installing high-performance windows is usually a better option than investing in energy-conserving blinds or shades.

Humabuilt Wheatboard doors are made from chopped wheat straw, a waste product of the agriculture industry. Humabuilt takes formaldehyde-free Wheatboard, reinforces it with lag-bolt construction on the stiles and rails, and then glues it all together with ultra-low-VOC, water-based adhesives. This creates a stable, sturdy door that will not warp, crack, or split. Available in a variety of styles and in paint or stain grade, competitively priced, attractive, high-quality, U.S.-made door that uses 85% renewable materials and can help maintain the health of the homeowners.