Summer is coming upon us swiftly. Soon, if you are in the Northwest U.S., then you will be outdoors enjoying all of the sun you can get. If you are in the Southeast, you will be inside with air conditioning, taking a break from heat and humidity.
But regardless of your area, there is one building feature that can aid in summer cooling and winter warming: heavy roof overhangs. Depending on thickness and positioning, big overhangs (or perhaps strategic awnings) can color a house in the summer and still allow warm light at the winter.
In general, a south-facing overhang will direct sunlight’s beams lower onto the window, allowing less light in and preventing that light out of heating up the house in the summertime. This implies less demand for air conditioning, less energy used and much less money spent.
A fantastic overhang will also allow more winter light to penetrate a construction than summertime light, thus allowing light and heat in during the warmer months, which again saves in energy and electricity costs.
Overhangs are most effective for south-facing elements (from the northern hemisphere) and at midday. If the building element bears more than about 30 degrees off south, the effectiveness of an overhang decreases, says the U.S. Department of Energy.
Even if you are not interested in saving money by lowering heating costs, large roof overhangs can still provide shelter and help protect a house from bad weather. Oh, and they seem good, too.
Coates Design Architects Seattle
Large roof overhangs on a house by Coates Design Architects in Seattle do much more than place a modernist stamp on the structure. They also shield it in the Pacific Northwest’s driving winter rain and mitigate hot summer sun.
Efficient Energy & Renewable Energy
This diagram by the U.S. Department of Energy shows how a roof overhang can stop hot summer sun from becoming in. Here, the summer sun’s angles are directed at the ground.
But that same smartly oriented overhang may also allow maximum light during the winter, as shown, when you want that extra bit of heat.
Diagram via DOE Office of Energy Efficiency & Renewable Energy
Warmington & North
Roof overhangs can be all sizes, and they need not be purely utilitarian. This one, on another Pacific Northwest house, provides all of the benefits of passive cooling and weather protection, but it is the drama of this overhang that will matter most. This house would be visually nude without this roofing.
One SEED Architecture + Interiors
A diagram by One Seed Architecture + Interiors at Vancouver, British Columbia, shows how roof overhangs block southern sun but how south-facing glazing permits sunlight exposure.
In this house, the thermal block partitions — exposed to sunlight during the winter — also absorb that winter sunshine and disperse the heat throughout the afternoon, helping to warm the house.
Not all of roof overhangs are designed solely for passive cooling. This is a unique architectural improvement, and it also protects individuals at the doorway from wind, snow and rain.
Besides supplying passive cooling and cooling, as in this case, roof overhangs also save doors and windows from bad weather (saving you money), and shield a home’s exterior and foundation from water runnoff.
The roof overhang on this house in Michigan’s Upper Peninsula, by Finne Architects, protects the house from sun, yes, but also from the Midwest’s heavy snow.
The Department of Energy has some region-specific recommendations for roof overhangs:
For cold climates, at base 65 degrees Fahrenheit, find the shadow line at midwindow employing the June 21 (summer solstice) sun angle.For moderate climates, at base 65 degrees during times when heat is necessary and base 75 degrees during times when air conditioning is necessary, find the shadow line at the windowsill using the summer solstice sun angle.For hot climates, at base 75 degrees, find the shadow line at the windowsill using the March 21 (vernal equinox) sun angle.
John Maniscalco Architecture
A house by John Maniscalco Architecture, coated in snow, showcases a sudden green advantage to big, flat roofs with overhangs: mild out of inside and exterior fittings is reflected and disperse by the bottom of the roofing. This implies fewer light fixtures and less energy used.
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Beard + Riser Architects
This house in Mississippi by Beard + Riser Architects is oriented along an east-west axis to optimize solar control. The front part of the house faces south and features a large overhang that folds over the edge of the roof to block direct summer sun. The translucent fiberglass panels along the porch overhang let filtered northern light into the house.
The construction zone, ltd..
Shallow roof overhangs may be best for northern regions, but at the south, heavy overhangs such as this one by The Construction Zone are ideal.
This house by Burton Architecture does not have to let much sun and heat in, as it is in Berkeley, California. It welcomes the color provided by this roof which wraps around two sides of this construction.
Tell us : Are you contemplating a large roof overhang? If you have one, please discuss a photo and tell us what area you live in.
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Innovative Home, Heated and Cooled by Design