Don't hesitate to flood a room with light, particularly on the north side. The north side is where constant light can fill the entire space very evenly all day. Try using larger windows where you can. The larger glass area adds light to the space, but you will want to use energy-efficient windows. Not using energy efficient windows could result in cold drafts in the winter, thermal heat gain in the summer, and higher energy bills all year round. Consider putting windows in unusual places, such as bathrooms and even shower spaces. This will bring in a ton of daylight and change the entire look of the area.



Don't discount using windows on a southwestern exposure, even in warm climates. Look for new glazing and low-emissive glass coatings that make windows more efficient and better suited to the specific exposure and application. Minimize east- and west-facing wall areas. These elevations feel summer sun most intensely. Maximize south-facing glazing as this will help minimize winter heating bills.

The right-sized overhang placed above south-facing windows can help minimize heat gain during the summer, when the sun is high in the southern sky, yet still emits warming rays during winter months. Provide for shade at south- and west-facing windows with an appropriate roof truss design, architectural features, landscaping plan, and decorating plan.

In warm climates, sunlight can overheat the home through windows on the south and west facing sides of homes. Roof overhangs can provide shade for these windows as well as improve the home's long-term ability to withstand rain. They will also allow you to open windows on a rainy day. Specify 24" eave and 12" rake overhangs when possible. Where overhangs will not throw shade, like first floor windows in 2-story homes, architectural features like lanais or awnings can offset potential heat gain that windows on southern and western facades might be subject to during the cooling season.

Try entrance doors with transoms and sidelights. Where space is limited, a single sidelight may work instead of two flanking an entry. Think about etched and translucent patterns for the sidelight glass if privacy or security is a concern. French doors with transoms above doors and windows can be added if the ceilings are at least eight feet high. If lower ceilings prohibit the use of transoms a wider window or bank of windows can be used.

Investigate using windows and skylights even where you might have been concerned about heat gain or loss in the past. New products, including high-performance windows, integral electronic blinds, and automatic timed closing devices can minimize such concerns.

Today's skylights units are sleek, leak proof, and easier to install with special integral flashing kits. Consider sun tubes or tunnels for areas in the middle of a structure, such as a hallway. Sun tubes are good alternatives in areas where there's not enough space for a skylight.

Tubular Skylights

Where windows are not practical due to elevation or a room's layout, tubular skylights can provide natural light while minimizing the size of the roof penetration. Tubular skylights have a roof-mounted light collector that reflects light through a metal or plastic tube with a highly reflective interior coating. The reflective tube guides the sunlight to a diffuser lens mounted on the interior ceiling surface that spreads light evenly throughout the room. They are frequently used in windowless bathrooms and closets where natural light is desirable and skylights aren't possible because of attic space above the ceiling.

They can also be used in other dark spots throughout the house, such as hallways and stairwells. In single-story homes they can even direct natural light to basements. Try new options in moveable, retractable opening curtain walls for residential applications. The following are a few of the common-sense tactics that can be considered when designing high-efficiency custom homes:

Maximize The Use Of Operable Windows

Aim for operable-window space equal to 6 to 7 percent of floor space. (Only the operable portion of a double-hung window counts toward this percentage, while all of a casement window's space counts toward the total.)

Use Thoughtful Window Placement

Place windows diagonally across from each other, rather than directly opposite, to encourage ventilation through, rather than across, a space. Incorporate whole-house/attic fans. Today's units are more powerful and efficient than models you might remember from your grandmother's home. In the evening, with windows and attic doors open, these fans can help flush out daytime heat quickly.

Locate Windows With Daylight In Mind

Good lighting begins with the effective use of sunlight. Consider the size, location, and primary function of the windows. Will the window frame a view, capture prevailing breezes, allow adequate light or provide architectural balance?

There is a tradeoff between the benefits of windows, such as daylight and good views, and the major drawback is reduced insulation value. Because even new windows have a much lower insulation value than walls, they should not exceed 15% of the wall area, unless the home is specifically designed to take advantage of passive solar heating. With proper window placement, there should be more than enough daylight in the home with 15% or less window-to-wall area.

Low-emittance (low-E) windows help keep heat inside in winter and outside in summer and - as a side benefit - protect furnishings from fading. They have a thin film applied to the glass that improves the performance of the window. These can cut out up to 95% of ultra violet rays in a home.

The two most important indicators of a window's performance are the U-factor and the Solar Heat Gain Coefficient (SHGC). The U-factor measures how well the window insulates. The lower the U-factor the better the insulation value. The SHGC measures how well the window blocks heat from the sun. The lower the SHGC, the less solar heat the window lets in. Each climate has optimum values for both the U-factor and SHGC. Remember, the better the window, the more comfortable - and more energy efficient - the home.

Window treatments, such as window films, can also be added to windows to keep heat from the sun from entering the home, although they have the disadvantage of darkening the home throughout the day. Shades and blinds can be closed during peak solar hours to prevent overheating.

Now that you know more about natural lighting and the impact it can have on energy costs it is time for you to get to work!