Bring In The Sun
When properly designed and oriented, a sunroom or three-season porch provides a comfortable way to enjoy your home's surroundings. Here's one sunroom's intriguing tale, followed by expert tips for a successful project.
A Sunny Tale
On a South Seas trip, the owners of this sunroom were inspired by the open and airy Javanese huts. Translating that traditional flat-roof structure into a room suitable for an American traditional home proved challenging but rewarding.
Originally, the structure was open -- just a glass roof and pillars. The roof was pitched to blend with the existing roofline, and the trim was kept in character with the home's Colonial style. To evoke the original flat ceiling, the owners draped fabric over metal rods attached to the rafters.
The glass walls came later, designed to add to the room's comfort in cool weather. The owners installed accordion-fold glass doors in overhead tracks so the room could be opened completely to breezes in the summer. No contractors were willing to tackle the unusual installation, so the owners did it themselves -- a challenging task, they report.
In winter, with the doors closed, the unheated space basks in the sunlight, so it's pleasantly warm even on overcast days. In summer, the couple throws open the doors so the breezes can enter. To create cooling shade, the owners change the overhead fabric to heavy green canvas.
Any house can benefit when attention is paid to its orientation to its surroundings. But for a porch or sunroom, orientation is critical to creating a comfortable, appealing space. Consider these guidelines as you plan your project:
Check the compass. In a room with lots of glass, proper orientation to the sun is vital. In the North, the majority of vertical glass should face south (or close to it). In the South, a sunroom will stay cooler if most vertical glass faces north. In hot areas, avoid large expanses of glass facing due east or west.
Orient skylights properly. Roof windows and skylights should generally face north, east, or west. Large expanses of south-facing skylights can turn a room into an oven. To light spaces evenly, use several skylights spread out over the roof.
Follow the sun. The sun's path is higher in the sky in summer than in winter. Take advantage of this fact by adding overhangs above windows. The depth of the overhang should be such that the window is shaded during the middle of summer days, but unshaded in cooler seasons. Your contractor or a local engineering firm can help determine the proper size for your area.
Remember ventilation and shade. The more windows you can open, and the wider you can open them, the more control you'll have over the temperature in the room. Place windows to take advantage of prevailing breezes. Use shades of various materials and consistencies to control light and heat build-up, while allowing breezes in.
Think energy efficiency. Even if you aren't heating the room, you'll be more comfortable if you build it as though it were being heated. Double-pane windows, insulation, and tight weather sealing can add days of extra usability.
Save solar heat. All-glass rooms tend to cool quickly in the evening and may overheat early in the day. To even out such temperature swings, consider adding "thermal mass" to the room. This means simply added heavy materials, like a masonry floor, that absorb heat during the day and radiate back into the room at night.
Be sure to talk with a knowledgeable contractor or engineer if you are serious about putting such passive solar energy techniques to work in your room.