Deciding whether or not to build a sunroom is the easy part. Once that decision has been taken, questions such as how large, what style, the type of flooring, the style and size of windows, how to deal with heating and air conditioning, the lighting and the location of electric outlets, and budgetary limitations are but a few of the sometimes difficult considerations linked to the design process. One such issue is whether to build a conventional shingle or glass roof sunroom. This can be a tricky and complex issue.
“Conventional shingle roof sunroom” is the term we use to describe regular additions usually built with rafters or trusses, a shingle roof, R30 or higher insulation in the roof, and a generous placement of windows and patio or other glass doors on all three sides. Conventional shingle roof sunrooms have several advantages. First, they are more energy efficient in winter than glass roof additions. Rooms built with substantial roof insulation (e.g., R30 and above) will outperform a glass roof addition in winter from an energy conservation perspective. Second, in summer, glass roof additions will let in more of the sun’s infrared heat than an opaque shingled roof. Infra red heat passes through glass, even when that glass is gas-filled with an enhanced insulation factor. And third, and as a general rule, conventionally framed rooms, and foam core patio rooms, are less expensive than high performance glass roof sunrooms.
But just as every equation has two sides, so it is in the debate between conventional and glass roof sunrooms. Although conventional additions may be more energy efficient in both winter and summer, and less expensive to build, the fact is that glass roof sunrooms have powerful points in their favour that will usually lead prospective buyers to choose this option. Too often, sunroom buyers remain sceptical of the winter and summer performance of glass roof sunrooms, fearing they will be too cold in winter and too hot in summer. And while it is true that sunroom glass is less energy efficient than an insulated shingle roof in summer and winter, the fact remains that ConservaGlass Select, exclusive to Four Seasons Sunrooms, does perform well beyond expectations in all types of weather.
With winter heating costs for example, ConservaGlass Select has proven to be remarkably efficient. One house in Ottawa with a glass roof sunroom measuring approximately 22 ft. x 11 ft., and with a 5 ft. roof extension which together added 37% to the main floor square footage of the home, experienced only a 5 _ % increase in gas consumption averaged over an twelve year period (1998 to 2010). And that sunroom faces due north. What makes this statistic all the more surprising is that at the time the sunroom was added, the hot water system was switched from electric to gas, thereby reducing the increased natural gas costs for incremental heating to less than 5%.
Equally important from an energy perspective, Four Seasons Sunrooms glass roof additions also perform well in summer. Standard double glaze thermals (i.e., two pieces of glass in a sealed unit) will let in approximately 90% of the sun’s infrared heat. Low-E argon, irrespective of its enhanced R value, still allows approximately 80% of this heat to enter the sunroom. By comparison, Four Season Sunrooms patented ConservaGlass Select roof glass will block approximately 85% of the sun’s infrared heat, allowing only 15% to penetrate the sunroom. While this number is not 0%, the reality is that a Four Seasons ConservaGlass Select roof is not far off an opaque shingled or foam core panelled roof in terms of infrared heat reflection and insulation value.
High performance glass is not the only reason many sunroom buyers choose a glass over a conventional roof sunroom. We all love light. Few would argue with that statement. Visit any city during the lunch break on a nice day and the first thing you will notice is a steady stream of office workers moving to the outdoors to enjoy the sunlight. On pleasant days we all enjoy the outdoors-and glass roof sunrooms can deliver that outdoor feeling right into your home the entire year.
One cautionary note. Buyers contemplating a conventional shingle roof sunroom should carefully analyse the impact of that new shingle roof, even with skylights, on the existing room or rooms to which it is to be attached. Whether it be a living, dining, family room, or kitchen, these rooms almost always have one or more windows or a set of glass doors facing the backyard and providing natural light to that room. Building a conventional roof over those windows and doors will dramatically cut that natural light and darken the adjoining room or rooms. For dining rooms, since they are used primarily in the evening, this loss of light may not be too significant. But for other rooms, particularly kitchens, this loss of light could be a major disappointment, and more important, could drastically affect the resale attractiveness and price when it comes time to sell. It is a well-known fact-people like light. Bright cheerful houses will always sell first, and at a premium. One way to gain some idea of the impact of that loss of light on your home is to temporarily place a tarp as close to the proposed roof location as possible, and to observe its impact on the amount of natural light now entering the adjoining room. And bear in mind, once the room is built with conventionally framed walls, that light will be reduced even further.
As a final point, few would argue that glass roof sunrooms represent a unique enhancement to any home. They are both spectacular and magnificent with the ability to change the character, traffic patterns, and perception of every home. They combine unparalleled styling and elegance with architectural flexibility. Their impact is simply dramatic. They offer an extraordinary alternative to an ordinary addition.