High Performance Windows

Many ENERGY STAR qualified new homes feature high-performance windows. High-performance, energy-efficient windows can improve the energy efficiency of your home by reducing heat loss in cooler climates and heat gain in warmer climates.

image map of house with links to ducts, envelope, windows, insulation, and equipment

Window technologies have advanced dramatically and prices for these windows have dropped significantly. Look for windows with the ENERGY STAR label. Heat gain and loss through windows accounts for up to 50% of a home’s heating and cooling needs. Many technological improvements have been made in recent years that have advanced the insulating quality of windows including:

Improved Window Materials

Advances in window technology such as double glazing and low-e coatings substantially reduce heat loss and gains. Look for ENERGY STAR or National Fenestration Rating Council (NFRC) labels to be sure you are getting high-efficiency windows.

Improved Framing Materials

Low conductance materials, such as wood, vinyl, and fiberglass perform better than aluminum. Look for “thermal breaks” where aluminum frames are used in heating-dominated climates to avoid condensation. Insulated frames, including insulating spacers between glazings, also perform better than uninsulated frames.

Air Tightness

High-performance or advanced windows need to be sealed around framing and other gaps that may exist. Caulks, foams, and weather-stripping work well to keep drafts out.

High-performance, energy-efficient windows can offer you:

  • Quieter home interior — multiple panes and insulated frames block outside noise.
  • Reduced fading of curtains, furniture, and flooring — low-emissivity (solar window) coatings can block up to 98% of UV rays.
  • Reduced utility bills — houses lose less heat in winter and absorb less heat in summer.
  • Improved quality windows are made from better-quality materials easier to operate and carry extended warranties.

Dig Deeper

Windows typically comprise 10 to 25 percent of the exterior wall area of new homes. Research studies report that windows in heating-dominated climates account for up to 25 percent of a typical house’s heating load and that in cooling-dominated climates, windows account for up to 50 percent of the cooling load.

In recent years, many technological advances have been made that significantly enhance the thermal performance of windows. As shown in Figure 1, these technologies include improved framing materials, low-emissivity and solar control coatings, low-conductance gas fills, improved thermal breaks and edge spacers, and better edge sealing techniques. These technologies can be used independently or in combination, but must be selected based on climate to optimize performance.

Windows can improve the thermal performance of homes by minimizing heat loss in heating-dominated climates and by minimizing solar heat gain in cooling-dominated climates. Thus windows with lower U-factors or higher R-values perform better in heating-dominated climates and windows with lower solar heat gain coefficients (SHGC) perform better in cooling-dominated climates (see Figure 2). SHGC is a measure of the amount of solar energy that a glazing material allows to pass.

The materials and design of the frame also influence thermal performance. Low conductance materials, such as wood, vinyl, and fiberglass, perform better than high conductance materials such as aluminum. Look for “thermal breaks” where aluminum frames are used in heating-dominated climates to avoid condensation. And finally, insulated frames perform better than uninsulated.

Air tightness is another important consideration. Windows are now being tested and rated for air tightness. A rating of 0.2 cfm/ft (cubic feet per minute of air leakage per linear foot of window edge) or lower is considered good. The best windows have a rating of 0.1 cfm/ft or lower.

An effective building envelope is a key element for an energy-efficient home. ENERGY STAR labeled homes are often constructed with high-performance windows that can improve the effectiveness of the building envelope and improve comfort.


High-performance windows can provide many benefits including:

Improved comfort. High-performance windows reduce conductive heat losses and gains resulting in warmer interior surfaces during the winter and cooler interior surfaces during the summer. In homes, approximately 40 percent of our physical comfort is due to the radiant heat exchange between our bodies and the surrounding interior surfaces. Thus, high-performance windows improve comfort by reducing this radiant heat exchange. In addition, improved frames reduce drafts and provide more consistent temperatures throughout the house.

Quieter home. High-performance windows often utilize multiple glazing and insulated frames. These features reduce unwanted noise from the outside.

Increased quality. High-performance windows are often constructed with better quality materials that can result in stronger, easier to operate, and longer lasting windows. As a result of these improvements, manufacturers frequently offer extended warranties on these products.

Improved indoor air quality. High-performance windows often have air tightness ratings of 0.2 cfm/ft or less which reduce the amount of unconditioned air leakage into a house. This air leakage can bring in dirt, dust, and other impurities that can negatively affect indoor air quality.

Lower utility bills. High-performance windows are better insulated and more air-tight. These features reduce energy consumption for heating and cooling which result in lower utility bills, making homes less expensive to operate.

Reduced obsolescence. Based on recent trends for improved efficiency, high-performance windows are expected to become standard practice for the building industry. Since it is both difficult and costly to replace windows after a house is built, it is best to install high-performance products during the original construction. ENERGY STAR labeled homes constructed with high-performance windows are, therefore, expected to be less vulnerable to obsolescence.

Fewer condensation problems. High-performance windows stay warmer in the winter resulting in drier windows with fewer condensation-related problems. Condensation can stain fabrics, lead to mold and mildew build-up, and in cold climates cause damage due to the freeze/thaw cycle.

Reduced wear on home furnishings. Low-E coatings can block up to 98 percent of the ultraviolet radiation emitted by the sun. This radiation causes curtains, window treatments, carpeting, and furniture to fade and wear faster.

Improved resale position. High-performance windows can provide the many impressive benefits listed above resulting in a more comfortable, quieter, and higher quality home with lower utility bills and fewer condensation and fading problems. These benefits can translate into higher resale value.

Source: EPA


State by State Window Recommendations


A Breath of Fresh Air: Ventilation Matters

Breath of Fresh Air When creating an energy-efficient, airtight home through air sealing techniques , it’s very important to consider ventilation. Unless properly ventilated, an airtight home can seal in indoor air pollutants. Ventilation also helps control moisture —another important consideration for a healthy, energy-efficient home.

Purpose of Ventilation

Your home needs ventilation—the exchange of indoor air with outdoor air—to reduce indoor pollutants, moisture, and odors. Contaminants such as formaldehyde, volatile organic compounds, and radon can accumulate in poorly ventilated homes, causing health problems. Excess moisture in a home can generate high humidity levels. High humidity levels can lead to mold growth and structural damage to your home.

To ensure adequate ventilation, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) says that a home’s living area should be ventilated at a rate of 0.35 air changes per hour or 15 cubic feet per person per minute, whichever is greater.

There are three basic ventilation strategies:

1. Natural ventilation occurs when there is uncontrolled air movement or infiltration through cracks and small holes in a home—the same ones you want to seal to make your home more energy efficient. Opening windows and doors also provides natural ventilation. Because of central heating and cooling systems, however, most people don’t open windows and doors as often. Therefore, air infiltration has become the principal mode of natural ventilation in homes.

A home’s natural ventilation rate is unpredictable and uncontrollable—you can’t rely on it to ventilate a house uniformly. Natural ventilation depends on a home’s airtightness, outdoor temperatures, wind, and other factors. Therefore, during mild weather, some homes may lack sufficient natural ventilation for pollutant removal. Tightly sealed and/or built homes may have insufficient natural ventilation most of the time, while homes with high air infiltration rates may experience high energy costs.

2. Spot ventilation can be used to improve the effectiveness of natural ventilation. However, if both spot and natural ventilation together don’t meet your home’s ventilation needs, then you should consider a whole-house ventilation strategy. Spot ventilation improves the effectiveness of other ventilation strategies—natural and whole-house —by removing indoor air pollutants and/or moisture at their source.

Spot ventilation includes the use of localized exhaust fans, such as those used above kitchen ranges and in bathrooms. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recommends intermittent or continuous ventilation rates for bathrooms and kitchens instead of using windows (natural ventilation): 50 or 20 cubic feet per minute for bathrooms, and 100 or 25 cubic feet per minute for kitchens, respectively.

3. The decision to use Whole-House Ventilation is typically motivated by concerns that natural
won’t provide adequate air quality, even with source control by spot ventilation .

Whole-house ventilation systems provide controlled, uniform ventilation throughout a house. These systems use one or more fans and duct systems to exhaust stale air and/or supply fresh air to the house. There are four types of systems:

Exhaust ventilation systems : Force inside air out of a home.

Supply ventilation systems : Force outside air into the home.

Balanced ventilation systems : Force equal amounts quantities of air into and out of the home.

Energy recovery ventilation (ERV) systems : Transfer heat and cool from
incoming or outgoing air to minimize energy loss.

Moisture Control Matters

Properly controlling moisture in your home will improve the effectiveness of your air sealing and insulation efforts, and vice versa. Thus, moisture control contributes to a home’s overall energy efficiency.

The best strategy for controlling moisture in your home depends on your climate and how your home is constructed. Before deciding on a moisture control strategy for your home, you may first want to understand how moisture moves through a home .

Moisture control strategies typically include the following areas of a home:

In most U.S. climates, you can use vapor diffusion retarders in these areas of your home to control moisture.

Source: US Dept. of Energy Consumer’s Guide to Energy Efficiency

If this information doesn’t scare you into hiring an experienced professional, nothing will. Click here to find a professional in your area who can assist you in building a tight, energy efficient, and properly ventilated home.


Cork: Revered Renewable Resource

I have a confession. Sometimes I like to think of myself as smart. There are many smart people, right? I have a degree. I made it thru 12 years of the military, that’s gotta count for something. My home state is world famous for “Yankee Ingenuity”. Smart right? Well, Not… So… Fast! I’ve been learning ALOT this last year after opening Green Builders Source. So many things that a laymen’s understanding didn’t do justice. Let me share my latest discovery! CORK! Cork Sample

Seems, my layman’s understanding of cork was woefully inadequate! Sure, there are the cork boards, the underlayment of engineered flooring, and then my personal favorite, the wine cork! Yummy! But it wasn’t until 1999 that I had even HEARD of a cork floor. Tile? Yup! Wood? Of course! Marble? Have you seen the Duomo in Florence? But Cork? Apparently it was all the rage in Europe! And I just lived in Europe for 5 years? How could I miss it? How?

Well, being the ever curious, I started to pay attention every time information on cork was available. Jump to 2008 and Cork is now a top player for any green building project. The top green choices almost always start with: Cork, Bamboo, Linoleum, and locally manufactured tile. Many don’t know why Cork is on the “Short list” for Green. Bamboo is obvious as it’s a grass, it can be harvested and rapidly renew its stalks for a future harvest. Tile is sustainable, that’s green. Linoleum is very natural and long lasting. But Cork? The harvesting of Cork is not yet as well known nor is how and from where it is harvested.

Cork oak cross sectionCork comes from the Cork Oak. A medium sized tree that can be found in southern Europe and northern Africa. An interesting piece of information that is quite indicative of our vocabulary is all trees generate cork as a layer between the old growth bark and the living inner plant cells. It is a major component of the tree bark that protects the inner growth cells and sapwood from disease, insects, and damage. (note this… it protects the tree from bacteria, insects, and damage) It can be harvested from any tree, but only the Cork Oak is commercially viable due to its thickness and ease of harvesting.

The harvesting is equally interesting and truly a sustainable commodity, if not entirely practical. A Cork Oak does live an amazingly long time, upwards of 200 years. However, the first harvest cannot be taken until the tree is 20 years old. This harvest is of poor grade and it is not till the cork has been harvested an additional 3 times, or when the tree is 50 that high grade cork is available. This thought quickly squelched my desire to create a Cork Oak orchard in Texas given my level of attention and interest would surely expire before the first harvest. I did entertain the “second generation” idea, but my children would probably be so bored of hearing of the future harvest, they surely would be interested in more rapidly rewarding endeavors. Maybe Bamboo is more our “speed”? That said, the following harvests can be made at 10 year intervals. This allows 15 or more harvests from one tree! Truly a quest for a forward thinking entrepreneur. Very forward thinking!

Here’s a summary from the Canada/Portugal Chamber website:

Given that a cork oak produces cork tissue until it is 150 or even 200 years old, during which time it Whistler - Worlds Oldest Cork Treemay be stripped 15 to 18 times, and that the average ages of trees presently in production is 85 years and that the area under plantation is growing by an average of 4% a year, cork production can look forward to a rosy future in Portugal. There are at present more than 600 industrial facilities operating in Portugal, employing a labor force of about 15,000. Cork products were exported in 1990 to the tune of 80,433,356,000 escudos (corresponding to 105,516 tons). In the same period natural cork stoppers accounted for 55% of total cork product exports. At 44,614,694,000 escudos, this trade is worth more than the export of Port Wine.

This only further clarifies that the commercial leaders in cork production are in Europe and Africa with Portugal producing 50% of the world’s supply. Don’t let the scarcity of the harvest locations fool you, however. Cork has a plethora of qualities that make it very desirable. It’s elastic in nature and near-water impermeable. It has low thermal conductivity, low density, fire resistance, and good energy absorption, antimicrobial, and resistant to insects, mold and mildew. (remember how it protected the tree as part of the bark?) All these factors make cork an excellent product for wine stoppers, sports equipment, sound management in musical instruments, and more. However, these qualities sound amazingly grand for use in construction.

Microscopic view of cork cellsCork cells are comprised mostly of air. This trait makes each cork cell act as a balloon or a gasket. Additionally, the cell walls contain a waxy substance called “suberin” which enhances the impermeable wall to liquids and air. The product qualities that are found from the features of cork are: reduced sound from dropped items or walking, cork has a natural feel, it insulates against temperature changes (It has an “R-factor” of 2.6), it is low maintenance, extremely durable, and above all, it looks great. I found during my research for this article that there are cork floor installs that are still in use today over one hundred years old! One is a church in Chicago that had cork flooring in 1890 and is still in use today! And I just learned that The Library of Congress has cork flooring installed. Did I mention the sound absorption! Libraries and museums love cork. So do child care facilities. Not that I quote “Bob Vila” much, but his website had this to say about cork: “Finished cork flooring can have the look of textured hardwood… the soft give of carpet, and the easy maintenance of vinyl….cork feels softer than hardwood and warm underfoot, making it an obvious alternative to carpet.

Because of its cellular composition, it is extremely durable and resilient. This makes it much less affected by impact or friction than hard surface floors such as wood, laminate or tile. One feature that I always get questioned on is its resilience. I too worried that such a “soft” product would fall victim to high heeled shoes and the like. Apparently that “elasticity” that I mentioned has a “bounce back” factor of 40%! So, no worries about your high heeled shoes! Once the pressure is off, the cellular structure returns to shape very quickly.

Ok, so now we know it’s water resistant, insect and bacteria resistant, resilient, durable, quiet, and insulating, what do you have to do to get some? First, there are suppliers all over including Green Builders Source. Check all your options, inquiring about thickness, colors, patterns, pre-sealed, and quality. Second, there are two options for installation. Your cork floor can be installed as glue down tiles or as a floating floor. The glue down tiles uses fewer materials, but requires a near perfect floor for installation. The floating floor with interlocking tongue-and-groove edges is easier to install, and repair, and ready to walk on, thus making it a popular flooring choice.

For the floating floor planks and tiles, the cork floor looks like any engineered hardwood. Locking or There is a wear surface made of a factory applied, UV rated varnish or sealer, a veneer of cork oak bark, a cork core, a moisture resistant hard rigid core, and a cork underlayment. This layered solution provides the best of both worlds. The price is on par with other engineered woods or ceramic tile, so any alternative should put cork within the same budget range.

Once you have decided on cork, and you think you have a source, before you install it, you better have a maintenance plan. Every floor requires maintenance right? Well, yes, that is true, but cork is a low maintenance floor. The good news just keeps getting better with this flooring, doesn’t it? The catch? There isn’t any. Pick up loose dirt with vacuum, broom or “swiffer®”. The most important step is to Damp mop. Do NOT Wet mop! Do NOT let water stand on the floor. Then spot treat any tough to clean areas. Water is cleaning solvent enough. If you have to add something, nothing more abrasive then a drop or two of dish soap. Given all the water-resistance of cork, the seams of the flooring would swell under standing water.

Photo from Pretty amazing, hun? I know that in the time it’s taken me to finish this article, I’ve walked the house twice to see which room would look best in that new Green Builders Source Cork Floor! It’s a toss-up between the children’s play room or the kitchen. I’ll keep you posted.

Angelique Grado
Green Builders Source

References for this page came from: Wikipedia, Nova Cork, Natural Cork, Bob Vila, Canada/Portugal Chamber, TexasParks.org, and several .edu sites.


Bamboo – Self Renewing Beauty You’ll Enjoy Year After Year!

bamboo flooring Mention bamboo and most people think lucky plants and tiki torches, certainly not hardwood floors. But as environmentally conscious homeowners search for green alternatives, bamboo has become a popular flooring choice. Hold a bamboo plank and its weight and density are similar to hardwood, Yet bamboo actually is a fast-growing grass that sprouts to maturity in five to seven years. Once harvested, the plant sends up another shoot in the same spot, making it one of the most eco-friendly products on earth.

“All wood for floors is considered renewable,” said Anita Howard of the National Wood Flooring Association. “But bamboo is designated as ‘rapid renewable’ and gets higher points with LEED and other environmental groups.” And it looks good, too. Unlike traditional oaks and maple, bamboo has an exotic, tropical appearance.

Bamboo flooring comes in two basic styles, depending on the manufacturing process.
Horizontal consists of strips of solid bamboo layered on top of each other to expose the natural bamboo growth rings. Vertical is created by placing the bamboo strips on their sides and laminating them together for a linear look with more subtle markings. Some manufacturers also offer strand woven bamboo products, made by taking strips and strands and weaving them together. The product is compressed under intense pressure and heat, making it one of the hardest and most stable flooring options available.

“It’s also the most green of all products because nothing is wasted in the process,” Joe Pleune, of Green Choice Flooring International, said. Natural bamboo is a creamy blonde color. Carbonized bamboo is a smoky, caramel hue, the result of longer boiling during the manufacturing process. Bamboo also can be stained or marbled for different effects, even hand scraped to give it a distressed appearance. The cost of a bamboo floor is similar to hardwood but can vary, considerably, depending on the manufacturer.

It is important for consumers to find a reputable supplier, she said. “We discourage people from buying over the internet because they really need to look at what they are buying,” Howard said. “It’s best to go with a local business you can trust in case of any problems. Green Choice Flooring uses bamboo that comes directly from managed forests in China. Harvesting the bamboo isn’t a threat to endangered panda bears because they live at higher elevations and eat a different species of bamboo,” Pleune says. Pre-finished bamboo floors can have up to 10 layers of clear finish with scratch-resistant top coat. It’s installed in the same fashion as tongue-and-groove solid hardwood and modern laminate flooring. “Bamboo definitely has become more popular in the past few years,” Howard said. “And I think the trend will continue as long as the green movement has legs.


Will Using a Central Vacuum System Help You Breathe Easier?

I would never have believed I could be passionate about a vacuum cleaner- but now wonder why anyone wouldn’t install a Central Vacuum System when they are building a new home?

After pondering on this for some time, I have come up with 3 possible reasons.
#1) They had experience with or heard by word of mouth about the lack of suction in the original models.
#2) They don’t like cleaning out the dust filled canisters.
#3) You can’t take it with you.

I can’t imagine life without my Central Vac.  Oh sure, I do remember, distantly, those memories of lugging around the old Electrolux canister vacuum.  I even recall thinking that it worked pretty well.  But all that changed when a wonderful woman named Julia entered my life.

I was working at the time on a 100 home project in Toronto, Canada when I met her.  We were just at the pricing stage of the next phase of new homes, so her timing couldn’t have been better.  She sold me on the concept of the Central Vacuum System, and since we were building homes in the middle to upper price range, I thought it might be a good idea to at least rough it in to all the houses.   I have never looked back.

But even as I write this, we have just moved into a new (old) home without a Central Vac.  For the last 4 months I have been living life with the ‘8 lb. miracle’, and the dust bag has still not filled up. Now some people might think that is a good thing, but I am wondering where has all the dirt gone?  I know how much my Central Vac used to pick up, and now we are in an older, and even dustier home. Unfortunately, I think I know the answer.  While the beater brush is doing a wonderful job making the carpets look freshly vacuumed, the colour of the carpet is actually changing in the high traffic areas.

As wonderful as the incredible suction power of the Central Vacuum is, what adds even more value to me is all the vacuuming options I have.  Like the little stair beater brush attachment, and the sofa ‘duster’.  My husband loved being able to vacuum out his car in the garage by just hooking up the extra hose into the garage valve. And with the unit being installed in the garage, I can actually hear the phone ring while I am vacuuming.  I love the narrow tool attachment that allows me to dust under the fridge and around the laundry appliances.  And the brush tool for ‘dusting’ the window sills and baseboards is a real time saver.  (Well, maybe not.  It doesn’t get done very often now.)  And a personal favourite is the super-long-extension-spider-destructo-wand attachment.

We don’t suffer from airborne allergies in our family, but I have heard from users who love Central Vac’s for just that reason.  Since many homeowners install the unit in the garage, no dust particles whatsoever are returned to the air inside the house improving the indoor air quality.  While I don’t mind vacuuming, I do dislike dusting.

The Central Vacuum units of today are available with a bag option for clean, easy removal of the dust.  And while we are at it, let’s debunk another myth:  you CAN take it with you when you go!  There is one warning however about using your Central Vacuum.  When you experience such incredible suction power, it becomes easy to believe you can get rid of almost anything up that hose.  But do not vacuum up the needles from your Christmas tree.  They can get tangled up in the corners of the piping and when the dust and fiber particles build up and compact over them you will develop a blockage.  You will probably need a professional to come and clean this out.  Can you tell I am speaking from experience here?

When you consider the rising demand for Central Vacuum, how much will it cost you when you go to sell your home, and your buyer is hoping for a Central Vac? If you are not sold yet on the benefits of a Central Vacuum System, you can always have your home roughed-in with the pipes and cover plates.  The unit can easily be installed in the future.  So what’s to say no to?  Invest in a Central Vacuum System, you’ll be glad you did.