There is no doubt that an increasing number of people worldwide are striving to make buildings significantly more environmentally friendly than ever before. For new home builders, this essentially means constructing houses using eco-friendly materials in ways that make them energy-efficient.
When it comes to eco-friendly windows, several factors must be considered. These include the material used for the frame, insulation, and their ability to keep the rays of the sun in or out of the home, depending on what is required. It’s about comfort as much as it is about reducing our carbon footprint and going green for the planet, because it’s the right thing to do. There’s another factor too: homes that are energy-efficient are cheaper to run.
In addition, some governments offer incentives to encourage less enthusiastic home builders to think and act green. In the US, there are at least eight different financial incentives, ranging from tax credits and home loans for replacing old windows with energy-efficient windows, to tax rebates for installing a solar hot water heater. There are also local incentives in most US states. Manufacturers and green-savvy builders can earn energy-efficient tax credits as well.
In Canada, the Office of Energy Efficiency at Natural Resources Canada offers federal grants and incentives as part of its ecoENERGY Retrofit program. Although this is more relevant to upgrades and refurbishments than new homes, it’s still a valuable resource.
Since the average person may not have the technical know-how to judge whether windows (or other products) are eco-friendly, the US Environmental Protection Agency and the US Department of Energy launched a joint program to improve energy-efficient products and practices. Called ENERGY STAR, this program awards products specific ratings. By using products with an ENERGY STAR rating, you know they meet the strict energy efficiency guidelines established by the EPA and the US Department of Energy.
In 2010 alone, North Americans saved enough energy to avoid the greenhouse gases that would have been caused by 33 million cars. According to ENERGY STAR, they also saved nearly US$18 billion on combined utility bills.
Energy Efficient Factors
In addition to ENERGY STAR ratings, Canada has an EnerGuide rating service (ERS) that determines the level of efficiency in homes on a scale from zero to 100. The higher the rating, the better, indicating that the house is well-insulated and airtight, meaning the owner won’t need to buy additional energy. It’s easy to see how windows can help improve a home’s rating. For a brand-new house, the ideal rating is at least 80—if possible, higher.
Windows are among the growing list of products that qualify for the international ENERGY STAR energy efficiency symbol. However, different climatic zones have different needs when it comes to suitability. For example, the type of window that suits a northern Canadian home will differ from the needs of a home in northern Australia. Within a single country, there can also be variations. For example, Canada alone has been divided into four climate zones, as explained on the Natural Resources Canada website: www.newhomes.nrcan.gc.ca. So, the most suitable eco-friendly window for your home will depend on where you live.
Whether you’re buying windows from an outlet like Lowes or Home Depot (www.homedepot.ca), or directly from one of the manufacturers, there are some other important factors to consider.
First, there’s the U-factor, which measures how well a window prevents heat from escaping and how well it insulates. Ratings range from 0.20 to 1.20, and the lower the number, the better the U-factor.
Then there’s the solar heat gain coefficient (SHGC), which measures the window’s ability to block out sunlight and maintain a cool interior environment. The lower the SHGC, the better the window is at blocking heat.
Another rating to consider is visible transmittance (VT), which measures how much visible light passes through the window. The higher the value, the more light you’ll see, reducing the need for artificial lighting.
The R-value measures resistance to heat loss. Since windows can account for up to 30% of the heat lost from a house, according to Natural Resources Canada, it’s clear how important the R-value factor is. High R-value windows are the most energy-efficient.
According to Serious Windows (www.seriouswindows.com), the most cost-effective energy-saving option is R-5 windows. As their experts point out, windows are one of the biggest sources of heating and cooling energy loss in our homes.
Another factor is the air leakage rating, which measures how much air can escape through the window. A well-made window will be airtight, while a cheap, poorly made window may have gaps and cracks at the joints, allowing air to pass through even when the window is shut.
Condensation resistance (CR) is another important factor. This measures the ability of the window to resist moisture forming on the glazed surface. CR is rated on a scale from 0 to 100, and the higher the number, the more resistant the window will be to condensation.
Lastly, there’s the design pressure (DP) rating, which measures the pressure the window can withstand when it is closed and locked. This is an important security factor, as well as an issue that relates to air entering and leaving the house and how strong winds may affect the window. The higher the DP rating, the more pressure the window can withstand.
Eco-Friendly Materials
Marvin (www.marvin.com and marvincanada.com) is a window manufacturer with outlets throughout the USA and Canada. The company prides itself on producing energy-efficient products that meet or exceed the tax-credit ENERGY STAR guidelines. In addition, they use quality recycled materials and make a point of recycling all their manufacturing by-products.
Their window frames are made of lumber or aluminum-clad wood. Products are FSC and/or SFI certified. The FSC (Forest Stewardship Council) certification ensures that the lumber was sourced from a sustainable, well-managed forest. Similarly, the SFI (Sustainable Forestry Initiative) certification guarantees that the wood comes from a certified sustainable source.
If you’re looking for eco-friendly windows made of wood, be sure to look for both of these certifications.
