How can you tell if a specific window will do what you want it to do? All products have specific ratings so you don’t need to take the salespersons word for it. Here’s what the ratings mean for you.
We get asked about the differences between bow vs bay windows all the time. We finally decided it was time to whip up a post with the correct answer for all to see.
To put it simply the difference is in the layout of the windows. Both bow and bay windows stick out from the house, but they have a different look. Bow windows are made up of equal sized lites or panels while bay windows have a center section that is larger than the sides.
We may need a picture for this one. First we’ll start with a bay window.
Ok, so that’s a bay window. 3 panels, and the center is larger than the sides.
Now, here’s a bow window: See the difference? The bow has several panels and they’re all the same size. A bow window can have 3, 4, 5, 6 or more panels, but they’re always the same size.
Is a bow window better than a bay window?
Nope, it is really just a style difference. Do you prefer the look of the larger picture window in the center or a bay window or would you rather have several symmetrical panels? One is not better than the other, they’re just different.
What is the price difference between a bow and a bay window?
The difference in cost is typically pretty small. Many manufacturers will charge more for a bigger window, but the difference between a bow and a bay is typically not a huge driver of the cost. A bow window with many panels (called lites) will typically cost more than a bay window with only 3 lites.
A cost difference of a few hundred dollars wouldn’t be unusual, but you shouldn’t see much more difference than that.
As you’re shopping for new windows be sure to check out our detailed window reviews here. If you’re looking for anything that you can’t find be sure to post a comment or send us an email. We read every single one and we’ll do our best to respond.
As you’re shopping for new replacement windows you may have heard of NFRC ratings. It’s important to understand what these ratings are and what they mean about your new windows. First of all NFRC stands for the National Fenestration Rating Council. They’re based outside of Washington DC in Greenbelt Maryland. They are the national body that sets the standards for replacement window ratings.
Just about all new windows and doors offered today are NFRC rated as they need to be in order to qualify for the Energy Star program. The mice thing about NFRC ratings is that they are clear. Every new window will come with an NFRC sticker which clearly displays the ratings for that individual window or door. There is no room for salesperson trickery.
Despite claims of their salespeople and long heat lamp demonstrations, Champion windows have average efficiency ratings.
The NFRC stickers will look like the example above. As you can see they display the U-Factor and the Solar Heat Gain Coefficient (SHGC) on the top line and the Visible Transmittence (VT Rating) on the bottom left side. These are the ratings that MUST be on each window.
On the bottom line this window from Champion Windows also shows the Condensation Resistance which is optional. Some windows, like the Simonton window pictured below, will have a blank space in the lower right side. There is nothing wrong with this, but it does indicate that they don’t want to advertise their rating.
Simonton Reflections 5500 window ratings
Why are NFRC ratings important?
These ratings are important because they are solid. They are not up for interpretation or subject to change at a moments notice.
We hear stories about salespeople with all sorts of bogus info. We see R-Values getting thrown around and hear about promises made to customers that are just plain impossible. The NFRC ratings provide a way to really evaluate what you’re actually getting to make sure it meets the promises you were made.
What should you do it the sticker does not match what you were told?
Whatever claims the company makes about the energy efficiency of their windows make sure to get them in writing. Let them know you’ll be checking it agains the NFRC stickers. If they match you’re doing great and if they don’t somebody has some explaining to do.
If you feel like you’re getting fishy numbers during the sales phase ask them for the real NFRC ratings. If the ratings you get don’t match what you were previously told then you know they were being tricky with you. If they were I would suggest you find another company. There are plenty of fish in the sea as they say.
Hopefully you caught these shenanigans during the sales process. If they’re not caught until the products are installed it will be harder to figure out a solution.
What if the windows do not come with NFRC stickers?
This probably means that the company removed them prior to installation which is a huge red flag. it may mean that they’re trying to hide something from you and there may be very little you can do about it at this point.
What’s the bottom line?
NFRC ratings are a great way to evaluate the differences between various window products. We see customers struggling with these evaluations all the time.
In fact, just today I got a call from one of our reps who was out meeting with a customer. The customer had asked our guy how thick the gap between the 2 panes of glass is. Before we go answering that question it’s important for us to identify what the customer is actually asking.
Does the customer care if there is 1/2″ or 3″ of space in there? Nope. What they want is an energy efficient window and some other company probably told them that you need to have this much space or that much space in order to be efficient. Of course the simple way to tell how efficient one window is compared to another is to look at the U-Factors on the NFRC sticker. If one is lower than it’s better and if it’s higher than it’s worse.
Does the space in-between the glass make any difference? Who cares. Either the ratings are better or they’re not better. The measurement of this dimension or that dimension don’t matter one bit. This is how NFRC ratings make window shopping easier.
If you’re looking for a window company right now, the best advice we have is to check out our list of the best window companies all over the country. You can find it right here.
Perhaps the most common questions we get are about tax credits for replacement windows. As we get towards the end of 2014 the big question on everyones mind is whether there will be a tax credit for replacement windows in 2015. The answer right now is probably not, but it’s nothing to worry about.
We know that’s not a very good answer, but it’s our government at work. The latest update is that after the Democrats lost badly in the mid-term elections in 2014 they quickly moved to pass legislation before they lose control of the senate. The initiatives they’re currently focusing on are tax credits related to ideas they support. Energy efficient windows and doors are certainly something the Democrats can get behind.
Will the legislation pass before the Republicans take control of the senate in 2015?
Nobody knows. What we do know is that last time tax credit legislation passed it was retroactive as long as folks purchased windows that met the current Energy Star guidelines. Our best advice is to make sure the new windows you’re considering for your home meet the more stringent 2015 Energy Star guidelines.
This newer generation of windows is more efficient than the older 2014 models and they’ll save you money in the long run. They will also likely be included in any new tax credit legislation.
If there is a 2015 replacement window tax credit our best guess is that it will be retroactive to 2014 purchases and frankly by mid-November most windows purchased now will be installed in 2015 anyway.
We encourage you to go ahead with your window purchase and to make sure you’ll be getting windows that will qualify just in case there is a tax credit next year. Any reputable company should be abel to tell you which windows will qualify and we have a post on the subject right here.
Have fun!
If you’re looking for a window company right now, the best advice we have is to check out our list of the best window companies all over the country. You can find it right here.
You may have read about the R5 Volume Purchase Program that the US Department of Energy came out with several years ago. The idea was to encourage the manufacture of R5 windows which would drive down the cost.
It was a decent idea, but it hasn’t produced much in the way of results. In fact most windows that meet these ratings cost the same today as they did back then. We’re not aware of any R5 window products on the market that have come down in price since this program was established.
Which windows qualify for this program?
The Department of Energy decided that any windows with a U-Facotr of 0.22 or lower would qualify. Of course most if not all manufacturers already offer windows that meet this criteria. About the only reason the costs of these windows are sometimes high is that the manufacturers price the most efficient options to provide the highest margins.
There is no manufacturing difficulty in producing a product like this and about everyone already does it. Could any company sell these products for less? Sure, but the Department of Energy is not likely going to be able to help.
Does this mean the R5 Windows Volume Purchase Program was a failure?
Not necessarily, but it certainly hasn’t been the success the DOE hoped for. Most if not all window manufacturers offer windows that meet this criteria, but homeowners in the most of the country don’t pick them with much consistency. For example, many (if not all) windows will need to go to triple pane glass to get that rating. Triple pane glass costs about $100 additional per window. If you have 10 windows in your house that would add about $1,000 to a typical project.
Will you get much benefit from windows like this vs typical Energy Star rated windows?
Probably not. If you live in a harsh climate the impact of the more efficient windows will be greater. If you’re in Maine or Minnesota you may want to consider this option, but if you’re in the more temperate parts of the country the savings will be much smaller.
That isn’t to say triple pane windows are always a bad deal. If you’re going to be in the home for a while and are looking for the most efficient option they can represent a great value. The bang for the buck gets smaller as the windows get more efficient so just keep in mind that the increase in cost will be greater than the increase in efficiency.
If you’re looking for a window company right now, the best advice we have is to check out our list of the best window companies all over the country. You can find it right here.
Shopping for replacement windows can be a bit daunting and even comparing replacement window ratings can be much more difficult than you might expect. Why is this? Because companies don’t want you to make sense of it. The companies that offer the “best windows ever produced by mankind” know full well that their windows aren’t really any better than other windows offered by hundreds of other local companies.
How then can you sort through all of the nonsense to get to the real info? First you need to understand the ratings. U-Factor and R-Value are common ratings used to measure efficiency. You may be familiar with R-Values as they’re used in insulation.
Simply put the U-Factor is the inverse of the R-Value. For example a windows is an R-4 then the U-Factor is 1/4 or 0.25. Of course if it were that easy everyone would understand it and there would be no need for this post.
Here’s a little history. Back in the day (say before 2008) windows were commonly sold based on R-Values. These are nice round numbers that are easy for consumers to understand. A very common sales pitch included prices for windows with an R-4, R-7 and R-10. The higher the R-Value the better so the R-10 cost the most and the R-4 cost the least. That pitch was very effective due to its simplicity. It was easy to teach the salesperson and it was easy for the customer to digest. The problem was that it wasn’t very accurate.
In 2008 the federal government came out with expanded tax credits for replacement windows that were based on specific U-Factors and SHGC ratings. Intently the R4-7-10 pitch went out the window as folks were now concerned with the 0.30 U-Factor required to qualify for tax savings.
Why did the feds base the tax credits on U-Factors?
We know a lot of things the government does don’t make much sense, but this one did. U-Factors as determined by the National Fenestration Ratings Council (NFRC) are a measure of the entire window. They take into account the frame, the glass, any additional options and they provide a clear measure of the effectiveness of the product. This is why the U-Factor remains the best measure of efficiency of a window long after the federal tax credits have gone away.
Why do some companies still use R-Values?
Because they don’t want to offer you an easy comparison. R-Values as given out by window salespeople are often measures of just the center of the glass of the window. This is the most efficient part of any window as it doesn’t take into account any spacers or frames or other parts. Of course you’re buying an entire window not just the glass. Looking at just the glass measurements doesn’t do you any good.
We routinely see companies advertising R-10 windows as being special, which is just silly. To accurately describe this an R-10 window would have a U-Factor of 1/10 or 0.10. Do these windows have U-Factors of 0.10? They do not. Why don’t the numbers add up? Because they company was trying to be tricky with the ratings.
So know you know that just about any window company offering R-Values is not being clear about the ratings, it’s important to remember that the Department of Energy put out an R5 volume purchase program a few years back. The ratings in this case were accurate. This was setup to drive down the costs of windows that exceeded the previous standards. It hasn’t been much of a success just yet, and we’ll have another post on the subject.
So how do you sort through all of this to find a great deal?
The easy way is to look at the NFRC ratings for the products you’re considering. Don’t take some R-Value from the salesperson. Just ask them for the real NFRC ratings and don’t take any excuses as to why the company can’t or won’t provide them.
Once you have that, you’ll be able to compare the options directly and you’ll be on your way to cutting through all of the clutter to find yourself a great deal.
Like most things in the window business stc rated windows or sound transmission class windows are often misunderstood or misrepresented by salespeople. We’ve heard all sorts of stories and explanations regarding sound control windows. The truth rarely gets out there, but here we will cut through the fluff to explain how the various options will work for you. We’ll look at what these ratings mean, where you will get the best bang for your buck and common mistakes people make when trying to keep their home quiet.
There are standard stc rated windows that can increase the efficiency of your home with specific options and then there are specially designed stc rated windows that are designed for very high noise applications around airports, railroad tracks, or busy city centers.
We’ll start with typical replacement windows.
It is very common to hear a salesperson tell a customer that triple pane windows are a great way to reduce sound transmission. That seems plausible as 3 panes of glass would likely be better than 2, but in fact it is not the case. Triple pane windows have smaller air chambers than double pane windows and they sometimes use thinner glass as well to reduce the weight. As a result, triple pane windows will sometimes be worse than a typical double pane unit and will almost never be better.
An easy way to get a better stc rated window is to add dissimilar glass. This means one pane of glass is thicker than the other. A common way to accomplish this is to use laminated glass. Laminated glass is like the windshield of your car. It’s actually 2 pieces of glass with a piece of plastic in the middle. In a double pane window like this, one of the panes will be thick because it’s laminated and the other pane will be thinner because it’s not.
This is typically the best way to take a regular residential replacement window and make it a better stc rated window. The rating will increase by up to 20% using this method.
So what do these ratings mean?
It’s always hard for folks to get their head around what does a rating of 27 mean or if another product has a rating of 33 how much better is that? One way to visualize this is to consider that a typical exterior wall with siding on the outside drywall on the inside will have a rating around 34. A wall with brick instead of siding will be a bit better.
Imagine being in a room with no windows, say a closet in your bedroom. If a firetruck pulled up outside with it’s sirens blaring you’d still hear it. Double pane windows are better than single pane windows, and double pane windows with laminated glass will be better than that, but none of these options are sound proof.
Are there better options?
Yes, there are better stc rated windows, but when you go too extreme the windows start to look a little unusual. This isn’t really an issue if you like on the side of the highway or the approach path to O’Hare, but if you’re just trying to block out the noise of those pesky kids next door you might want to weigh your options. The Quiet Line from Milgard. It uses 2 sashes to provide an extra layer of sound insulation.
Notice how this window has 2 bottom sashes. It achieves excellent stc ratings, but the sacrifice is that it is a relatively unusual configuration.
What are the common mistakes people make when trying to keep their home quiet?
The number one mistake we see folks make is to install fancy new triple pane windows in an effort to reduce the sound transmission. As discussed above that is typically a waste of money.
The other common mistake is to think that after installing new windows their home will be completely silent. The fact is that’s just not the case. New stc rated windows can make a substantial improvement in the efficiency of the home, but sound is getting in through your walls, your ceiling and your floor. Depending on how your home is built, there may not be an easy way to completely block out those pesky kids next door after all.
If you’re looking for a window company right now, the best advice we have is to check out our list of the best window companies all over the country. You can find it right here.
Design pressure or dp rating is a measure of the strength of a window. It will tell you how well a product will stand up to high winds. The higher the dp rating the stronger the window. It does not relate to energy efficiency, but dp rating is still an important factor to consider.
What’s a good dp rating?
Typically you’ll see residential replacement windows with ratings from 15 to 50. Higher is better. It makes more sense to focus on dp rating when you’re in a situation where wind is of particular concern. For example we if you live on the water or up high on a hill where you’re exposed to the elements this can be important. In those situations I’d suggest going with at least a dp 30 and a dp 50 might be an even better choice. There’s really no need to go any stronger than that unless you’re in a high rise or a hurricane zone.
How can understanding dp ratings help me?
A common sales ploy is to show folks a cutaway view of a thick window next to a thin window and tell them that the thick windows is “strong” and the thin window is “weak”. This is intuitive which makes it an effective way to sell the thicker windows.
We can tell if a potential customer has seen this maneuver when they ask how many chambers are in a specific window or when they ask to see a cutaway.
As you’re considering these options keep in mind that everything in life has tradeoffs and everything in the window business can be measured so you don’t need to use a gut feeling. The thicker window will have a lower vt rating because that thick frame blocks a substantial amount of light, and the thinner window, if well built, could easily have a higher dp rating meaning it’s actually stronger.
So how do you avoid getting sold on something that you don’t necessarily need?
Just like always, avoid taking someone’s word for it and ask about the dp rating. If it’s higher it’s better. The window doesn’t need to be thick to have a higher rating and a thick window without a higher rating is blocking light for no purpose other than to say it’s “better”.
Remember that the cutaway sample really doesn’t show you anything. It gives you an idea, but the rating tells you for sure. There’s no need to guess when it’s so easy to be sure.
If you’re looking for a window company right now, the best advice we have is to check out our list of the best window companies all over the country. You can find it right here.
Air infiltration or air leakage ratings are an important factor to consider when comparing energy efficient replacement windows. In this post we’ll look into how these ratings are often misinterpreted, what is considered to be a pretty good rating and what to watch out for as you’re comparing the options.
To understand the rating you’ll first need to understand what the number actually represents. The unit of measure for air infiltration is cubic feet per minute per square foot. That is how many cubic feet of air can pass through the window in a minute at a constant 25 mph wind divided by the total window area. I know, the unit itself is a little tricky.
How are air infiltration and air leakage ratings misinterpreted?
Manufacturers are always looking for a way to tell folks that their products are “better” than another. Focusing on air infiltration ratings is an increasingly common way to do that.
For example, the manufacturer Soft-lite uses a chart in their Elements window brochure that some customers could easily misinterpret. It tries to put air infiltration in terms of how many milk jugs or pop cans of air can get through the widow. Unfortunately, it clearly leaves out the size and the style of the window being tested.
Since the unit of measure for these ratings has the total window area in the denominator the size of the window affects the rating. There are also several options offered by manufacturers that do change the ratings. For one company to say that they’re rating is XX is oversimplifying the situation.
It’s also worthwhile to consider how often your home is hit with a constant 25 mph wind. I’m not much of a sailor, but I’m aware of the wind enough to know that doesn’t happen by my house very often.
Manufacturers do this to try to separate themselves from their competition and there’s noting wrong with that, but trying to say a 0.01 difference in anything will make or break a project is pretty silly.
So what is a good air leakage or air infiltration rating?
Obviously the rating of how much air can get through the window is important. The American Architectural Manufacturers Association (AAMA) says that any residential window that achieves a rating below 0.30 cfm/sqft meets the requirements for their gold rating. This is the best rating they offer. This is also the minimum air infiltration rating for the energy star program. In fact, many of us in this business expected this minimum rating to be reduced with the 2015 energy star program, but it was not. I expect we will see changes to this standard in the years to come.
High quality vinyl replacement windows consistently achieve ratings MUCH lower than this standard. For a vinyl double hung window anything below 0.05 is pretty darn good. Casement windows and picture windows are typically even lower while sliding windows are often the worst of the bunch.
On the other hand, wood, fiberglass and composite windows typically cannot achieve as tight of a seal. These products typically have much higher air infiltration ratings. The fact that wood, fiberglass and composite windows typically have substantially worse air infiltration or air leakage ratings should be weighed when considering those options.
What should I watch out for when looking at air infiltration ratings?
Typically it is wise to avoid putting too much weight into statements from folks who are drastically over simplifying things. For example if a salesperson tells you his windows achieve a rating of 0.01 and that everything else is worse and any other window will make your house drafty he’s not telling you the truth (he’s probably the guy using the chart above).
Remember for vinyl windows anything below 0.05 is pretty darn good any you’ll likely never know the difference. In fact, the National Fenestration Rating Council or NFRC doesn’t even give ratings below 0.10 because they don’t believe the air infiltration measurements are accurate below that point. If the major independent testing body in our industry doesn’t recognize ratings below 0.10 that’s probably a good sign that you don’t need to worry about it below that point.
Important points to remember:
Air infiltration or air leakage is just one factor to consider as you sort through window ratings
It’s pretty easy to compare the differences between models
Lower is better, but below a certain point there is not much difference
Wood, composite and fiberglass options will typically have higher ratings than high quality vinyl
All types of windows are available below the 0.30 threshold
Not all types are available below the 0.10 level
If you’re looking for a window company right now, the best advice we have is to check out our list of the best window companies all over the country. You can find it right here.
The requirements for 2015 energy star windows have changed. The department of energy originally proposed that the new changes take effect in January 1, 2014, but many manufacturers were not yet able to produce the newer more efficient products so the date was delayed by 1 year. The good new for consumers is that many manufacturers are able to produce 2015 energy star windows NOW. This lets you get a more efficient window today.
How have the requirements changed for 2015 energy star windows?
This chart shows the climate zones:
Map of 2014 and 2015 energy star climate zones for replacement windows and doors.
And this one shows the u/factor and shgc requirements in each climate zone:
This chart shows the 2014 and 2015 energy star windows requirements
You can see that the u-factors and solar heat cain coefficient (shgc) requirements have gotten stronger depending on which climate zone you are in. The air infiltration (or air leakage) requirements have not changed which surprised most folks in the industry. We expect to see this requirement get tougher in the coming years.
Are there tax credits for purchasing 2015 energy star windows?
Not right now. Tax credits for energy efficient windows come and go depending on the will of congress. There may be state or local credits available in your area. A great resource to find information on these programs is the Database of State Incentives for Renewables and Efficiency or DSIRE. They’ll have all sorts of additional info.
In the past they have enacted retroactive tax credits for replacement windows purchased while no tax credit was in place. This may well happen again. To be sure you’re covered in case this happened you should be sure to at least get energy star qualified windows.
2015 Energy Star windows are more energy efficient than windows that met the 2014 energy star standards.
Remember, there is no need to buy windows that meet the 2015 standard in 2014, but it might be a good idea to buy the newer models rather than the older models as they’ll be in your home for many years to come.
If you’re looking for a window company right now, the best advice we have is to check out our list of the best window companies all over the country. You can find it right here.
Perhaps one of the easiest ways to tell if a window option you’re considering will perform as you’d expect is to look for the energy star windows logo. The department of energy puts together the guidelines for energy efficient windows and they provide a pretty solid benchmark for performance.
As you might expect the someone in Maine doesn’t need the same windows as someone in Arizona. The department of energy divides the country up into climate zones, each with their own requirements.
For 2014 the requirements energy star windows requirements are the same as they’ve been for a little while and every manufacturer will have qualifying double pane options. You can see the requirements for your climate zone in this chart:
Basically, the differences in requirements across the country come down to the idea that in the colder areas you want the heat from the sun to help warm your home in the winter and in the warmer climates you’re more concerned about keeping the solar heat out in the summer.
As you can see in the chart, in the north and north-central regions a solar heat gain coefficient (or SHGC) as high as 0.40 will qualify, but in the south the max qualifying SHGC is 0.27.
The differences in required u-factors are a little less intuitive. Basically this comes down to the fact that in the very warm southern climate zone the u-factor is almost irrelevant. If the window keeps the suns heat out it qualifies as energy star windows. As you can see a u-factor as high as 0.60 can still qualify in these areas. That’s not a particularly efficient window, but if it reflects enough of the suns heat to get to a SHGC of 0.27 then it does the trick.
In climate zones that experience both hot summers and cold winters the requirements are a little more balanced.
The long and short of it is that if you want a quick way to tell if a product is pretty good this is a great place to start. There absolutely are more efficient options out there, and you certainly may want to consider them, but the bang for your buck starts to diminish as you get more efficient.
Are there tax credits for new windows?
Currently there is no federal tax credit available for energy star windows, but our friends in congress may well pass a retroactive tax credit (it’s been done before). If they do you’ll probably only qualify if you purchased energy star windows.
One could write an entire post on the wisdom (or lack thereof) in implementing a tax credit designed to incentivize a specific behavior (purchasing efficient windows) and then making it apply to people who have already made the desired decision without the need for the incentive. Perhaps we’ll leave politics out of this party and save that conversation for another day
Are the 2015 energy star windows requirements any different?
If you’re looking for a window company right now, the best advice we have is to check out our list of the best window companies all over the country. You can find it right here.
See the difference? The bow has several panels and they’re all the same size. A bow window can have 3, 4, 5, 6 or more panels, but they’re always the same size.
