Category: Windows

So much of our life in the United States is heavily influenced by and similar to Europe. However, one area that has some pretty significant differences is in the design and construction of windows and doors. When you look at how life in Europe evolved and has more mixed-use, urban influences to residential design, as well as some of the climate factors, it makes sense that the focus around window and door design would vary some. 

Window Differences: How European Windows and American Windows Vary

Materials in Windows

While materials are often the same (e.g. wood, vinyl, aluminum, fiberglass, and, of course, glass), the construction of the windows and doors are often different. One of the main differences between European and American windows is thermal breaks and insulation used within the construction. In Europe, windows are typically made from wood, aluminum, or uPVC; these materials are generally more durable and energy-efficient, and they allow for a variety of design options. The “u” in uPVC stands for “unplasticized” which means that the PVC doesn’t expand and contract as much. 

Also, Europeans, and increasingly here in the US, design lots of chambers within the profile that increase structural integrity while reducing conductivity and convection currents with the assembly. The structural stability increases and the sizes can be larger. In European Aluminum windows, the thermal breaks tend to be more substantial and more effective at reducing conduction through the assembly. In contrast, American windows are often made from standard PVC or fiberglass, have less or no insulation, and have smaller, less effective thermal breaks in the aluminum systems. In addition, the spacers are often different. In Europe, they often use a composite spacer between the glass which has lower conductivity whereas in the US, highly conductive metals like aluminum or galvanized steel are often used. While materials might be less costly, many US products are not as energy efficient or as versatile in terms of design.

Installation of Windows

Another key difference between European and American windows is the way they are installed. In Europe, windows are typically installed from the inside of the building with anchor brackets vs. nail fins (preferably called screw fins). This allows for a more secure and energy-efficient installation, as the window can be sealed tightly against the frame. This also allows the windows to “sit” in the middle of the insulation layer boosting the overall wall performance to a small degree. In America, on the other hand, windows are typically installed from the outside of the building. This allows for easier installation, but it can result in gaps around the edges of the window and allows for wind-washing which cools the window and impacts energy efficiency.

Going In or Out

Another difference between European and American windows is their opening and closing. In Europe, windows are often designed to be opened in a variety of ways, including hinged and casement. European casement-style windows often tilt/turn inward with a dual action. See the video below by Todd demonstrating this window operation. This allows for greater flexibility and ventilation. In the United States, on the other hand, windows are typically designed to be opened by sliding or tilting. This is a simpler and more cost-effective design, but it can limit ventilation options. When US casement windows are designed, they typically open outward with a crank handle. 

Focus on Efficiency

Finally, the energy efficiency of European and American windows can vary greatly. In Europe, windows often have a higher focus on energy efficiency, with typically 3 panes of glass and advanced air sealing technology – multipoint locking. This helps to keep heat in during the winter and out during the summer, reducing energy costs and improving the building’s overall energy efficiency. In America, on the other hand, windows are more cost-effective and simple in their design. Sustainability and energy efficiency is growing in popularity but is still working hard to catch up to the efforts that have been standard in much of Europe. 

Come and Knock on My Door

Door design also has a few striking differences between US design and construction compared to European design. 

Sash Clearance: US entry doors have a higher sash clearance at the threshold, whereas European doors have a much smaller sash clearance. Designers should keep the clearances in mind if homeowners want  ¾” wood floors, and then throw rugs. In these cases, the door will need to be installed higher so the door will open.  

Frame/Jambs: US door frames/jambs typically use a 1X for the jambs. Compare this with the European style, which can be bulkier and have a clear opening that is much smaller than US doors. 

Balcony Doors: These style doors are much more common in European design. They typically do not have a low threshold that you might find with an entry door, and, instead have a window frame at the threshold. It’s a more cost-effective way to create a larger opening and allows a large window to act like a door. It’s not ideal in high-traffic areas, but with more compact city living in Europe, you’ll see them on balconies and low-traffic areas. 

Sliding Doors: European sliding doors include a lift slide design, where the handle of the door is actually a lever that lifts the entire sliding portion of the door off of the threshold while pushing rollers down to lift the door. European-style sliding doors also come in a style that includes a tilt/slide but has a high threshold similar to balcony doors. Also, similar to balcony doors, these don’t work well in high-traffic areas. 

We’re starting to see more lines blurred between US and European design. Many of the European features are starting to cross over and impact designs here in the United States. As a result, we’re seeing greater efficiency and performance, lower barriers to entry in cost and availability of designs, and greater ease to build a house with Passivhaus principles! 

At AE Building Systems, we’re devoted to providing the highest quality products, especially when it comes to windows and doors. We’re seeing the trends as they’re changing, and know the differences to help contractors and homeowners make the right decisions when it comes to their product selection. Got questions? We’re always happy to help! 

You thought windows were really simple and easy, right? Well, think again, my friends! When you pair high-efficiency windows with high altitude and differing sun exposures, you soon discover there are many possible ways you can not only optimize your window performance, but also set yourself up for failure!

Thin Air

Altitude is no joke, and you can literally feel it when you come from lower lands or sea level to visit a state like Colorado. The locals will all tell you to drink lots of water and if you try to go for a light jog, you may feel like you actually just attempted a marathon instead. The altitude has a real and major effect on the body. The same is true with windows. 

Why Does Altitude Matter?

High-performance windows today are equipped with triple and even quad glazing to form insulated glazing units (IGUs). IGUs have an airtight seal around the perimeter and trap the gas between the panes. Typically, gasses like argon and krypton are used. 

IGU’s perform best when they are assembled at the altitude where the final installation is. When IGUs are transported from a factory at sea level to a place with high elevation like we have in Colorado, it’s a recipe for disaster. When the altitude delta exceeds 1,600 feet, it becomes problematic because the barometric pressure varies enough to create complications. For example, when going up to 5,000 feet in elevation, the atmospheric pressure is much lower than at sea level. Think about what happens to a bag of potato chips. Most mainstream companies don’t gas fill and insert a capillary tube so the glass doesn’t break or even blow up in transit. Alpen HPP uses breather tubes and balloons to regulate barometric pressure of the gas used in their windows. There are other ways to manage barometric pressure to include pressure release valves as well as pre-pressurizing in the factory to the average barometric pressure for the installation location.

Hello, Mr. Sun!

If you’ve ever been in Colorado on a sunny day in the winter when it’s around 50 degrees, you may have experienced some hot flashes in your car where you scurry to get your air conditioning going. Wait a second! In the winter?? Yes, my friends, the sun is that intense here at higher altitudes and especially when it’s streaming through the glass of our cars. 

Now, let’s apply that to our homes. Solar heat gain coefficient (SHGC) is the fraction of solar radiation admitted through a skylight, door, or window, whether directly and/or absorbed. That radiation manifests as heat within the home. 

A lower SHGC window reduces solar heat and provides greater “shading” essentially. Glazing products with low SHGC ratings are more effective at reducing cooling loads during the summer by blocking some of the heat gain from sun radiation. Even up in the mountains, low SHGC glass is often used on the west elevation of a home to reduce summer overheating.  A glazing product with a high SHGC allows more solar heat gain which is great in colder months. Your home’s climate, orientation, and shading will drive the optimal SHGC for each window, often depending on the elevation or which side of the building the windows and doors are installed.

Please do not mistake SHGC with UV; these are different things. That said, one of the benefits of Alpen’s High Performance glass is it protects against up to 99.5% of UV rays. UV rays are damaging to virtually everything, including our skin. Related to windows, UV rays can damage nearly every finish in our homes and UV protection keeps interior finishes, wood, and furniture from getting damaged and discolored.  

Where Higher SHGC is Helpful:

In colder, heating-dominated northern climates, both SHGC and a window’s U-factor should be taken into account for energy efficiency. In heating climates where heating is a bigger concern than air conditioning, a higher SHGC in the range of 0.30 to 0.60 can be helpful especially on our south windows. During the winter months, the sun is lower in the south sky and the solar heat that is gained from the sun helps warm our homes.

Where Lower SHGC is Ideal:

In the Southern and Central states, where the climate can get extremely warm and air conditioning is used extensively throughout the majority of the year, a lower SHGC is ideal and desired. This equates to less heat gained from our windows. 

With most of our projects, we tune the windows by the elevation (North, East, South, West).  There have been rare occasions that windows even on the same elevation might have different SHGCs.  A north-facing window is going to behave differently than an east, south, or west-facing window simply based on the position of the sun throughout the day and the seasons. If you “tune” each window to be a specific value, make sure that each window is tagged properly and that the contractor pays attention to where each window needs to be installed, which is critical if you have a lot of the same sized windows. 

Of course, specifying this level of detail on each window is as much a science as it is an art. Note that SHGC levels generally run parallel with the visible transmittance of natural light.  While not noticeable by most people, there are slight hue differences with different SHGC glass. We know that every home’s windows are not just built to function well, but also to enhance a view and afford us natural light. In the mountains, we have some pretty spectacular views! Often, it’s a real-world balance to get the best performance while considering natural light in the home. [NOTE: it’s recommended to consult with an energy modeler in the process.]

So, those simple windows don’t seem so simple anymore, eh? There’s actually a whole lot more going on to make sure they will work optimally for your home. When you put this level of attention into your window design, you really can achieve some amazing results in performance, and as fans of sustainable, efficient homes, we love that! Love the idea of high-performing windows in your home too? Not sure where to start? Let us help you break down some of the basics and how they might apply to your home’s strategy.

When we moved into our home, it was an adventure! As we got to know the neighbors, we’d hear stories about the former owner. One such story included how the elderly woman would go away for a week on vacation and leave all of the wooden crank windows wide open so that her cats could come and go as they pleased. What did this mean for us? Well, for one thing, you could literally see the light streaming through the frame because the wooden window frames were so warped from the elements all season long. 

Needless to say, one of the first projects we tackled was replacing ALL windows to high-performance windows. We know we’re not alone here! Most homeowners come across energy loss from their windows after moving into a new home. Often, they blame it on drafts in the home, or simply settle for the fact that stratification and convection currents are part of their lives. But, it doesn’t have to be this way!

Why do high-performance windows and high-performance building envelopes matter? 

1. Conserve Energy: High-performance windows and building envelopes simply don’t waste resources. But when you have major thermal bridging, stratification, etc. you are paying to heat/cool a space as well as the outdoor space surrounding your home. You’re literally wasting energy every single day. (And, sadly, we see this in both new builds AND retrofits too.) 
2. Running Out of Resources: Our world is quickly burning through common energy resources. In a few hundred years, we will largely deplete our in-the-ground energy which was created over hundreds of millions of years. Much of the coal, oil, and natural gas derives from decomposed plants (photosynthesis) and animals from long ago. We hear people refer to that energy as prehistoric solar energy.
3. A Mess For Future Generations: Do we care about how we’re leaving the earth for our childrens’ children and beyond? Literally burning through resources does nothing to help our future generations. 
4. Climate Change: Stay with us here…whether you have given into the politicized side of this or not, our climates are changing around us and there’s scientific proof to back it up. Using less energy resources to heat and cool our homes is a simple way we can help make a dent. 
5. Save $$$: If you’re not convinced already, maybe saving a ton of money will help get your attention. Using less energy to heat or cool a home by using high-performance windows and building envelopes means less money you’re spending each month. Some parts of the country and world experience this more than others. For example, homeowners in the Northeast spend roughly 1.5-2.5 times more in energy costs than residents in Colorado! Of course those numbers are changing constantly, but it’s a good picture of how smart building systems can make a difference!
6. Future Savings: As energy costs increase (which they regularly do and will continue to do as traditional energy sources deplete), your costs can stay more normalized. The more energy-efficient your home is, the less you flux when prices change in energy. High-performance windows/building envelopes are kind of a hedge, if you will, against rising energy costs. The 625 windows will help as well, but 925 will help even more. 
7. Peace and Quiet: The higher the efficiency of your windows and envelope, the greater privacy and “peace and quiet” you’ll have in your home. Whether you have a baby sleeping, work from home, or just love some silence, high-efficiency windows can make a great impact. 
8. Greater Comfort: Most importantly, your house will be more comfortable. You will have fewer drafts which are actually more often convection currents. Also, you will be able to read a book next to a window in the winter in a t-shirt without feeling the cold as much. There are a lot of factors that go into a “comfort quotient” and you can go into intense detail if you want on this. The main thing is that if you build for energy efficiency, your home will have less drastic temperature swings from zone to zone and you’ll be more comfortable while in it. 

Ready to help improve your life AND help out our world’s energy problems? Building with high-performance windows and building envelope strategies is just one simple way. It’s a win-win for all. It’s an investment on so many levels. If you’re considering this kind of construction, we’d love to help you find the perfect materials for your project.

For additional reading, check out this recent blog post on “Eco-Friendly Ways to Prep Your Home for Winter”

Have you or your clients had significant sticker shock when the window and door bids are provided? It is pretty common… but there are ways to reduce cost without sacrificing much and often while improving performance.   By Value Engineering (VE), you’ll help save money with your project and there are several concepts to consider to make it happen.  

Value Engineering is often an untapped resource in projects that can save costs on a project without necessarily compromising quality and often while improving performance. Experts in Value Engineering can help identify opportunities to create a more efficient setup, especially when it comes to windows. Since we, at AE Building Systems, are always concerned about energy efficiency, we are proponents of anything that improves performance first and foremost. 

Considering performance vs. cost savings, in the window world, they often go together.  Whether you’re looking at many window manufacturers or options within the same manufacturer, there are a number of VE options that can actually save you a ton of money, and improve energy efficiency at the same time. The homeowners will pay less at the front end while saving money down the road in energy costs. That’s why we’re big fans of Value Engineering around here. 

Worried you might be spending too much on windows and doors? You might consider some of these options:

• Consider the location/region: The best way you can design effective opening is to design for the homeowner’s climate zone. The product someone needs in San Francisco (e.g. double, triple or quad-pane) are going to be drastically different than what you would want in Anchorage, Alaska. The best way to think through this is to look at the glass performance and how many panes and what type of gas-fill you’re needing. In Colorado, the front range (climate zone 5) can generally use a different glazing package than some of the colder mountain locations (often climate zones 6 and 7).
• Note the purpose of the space: What is the opening used for? Windows for a kitchen or bedroom are going to need higher performance compared to that of an unconditioned garage or three-season porch. You can get by with lower performance windows in some spaces. If the garage is conditioned which is often the case in mountain areas of Colorado, this might not apply.
• Selected fixed units where you can: Any time you have operable windows, you increase costs compared to fixed windows. They’re just more complex than a fixed window and fixed or picture windows also perform better – not only do they perform better thermally, they are tighter – reducing air infiltration. If it’s feasible that the homeowner is never going to open the window – go fixed. On the performance side… sliding or hung windows also open you up to greater air infiltration through the unit over casements, awnings and tilt/turns. Comparing hungs and sliders to fixed or casement units is a night and day difference. If you don’t need an operable unit in the space, opt for the fixed unit and save your money now and in the future. If you need an operable – try to go casement, awning or tilt/turn rather than hung or sliding due to the air infiltration rates. 
•  Overlooked the materials: The materials your units are made from can make a huge impact. Wood and aluminum are often more costly than vinyl and fiberglass. If wood is the look you need, different species of wood can vary in price. Keep this in mind as you determine what material you really need.

• Use fewer IGUs if you can: Consider various diagrams of the unit and how many Insulated Glazing Units (IGUs) you really need. In the high-performance arena, frames are a known culprit of energy performance. If you can consolidate windows within an assembly, you’ll get better performance and lower initial cost simply because you have less frame material and less labor.  The second window below is one IGU with simulated divided lights (SDLs) where the first unit below has 6 IGU’s. The price difference on these two units is significant and using 6 IGU’s can more than double the price of a window assembly.  
• Be mindful of the hardware (generally door hardware): We often think about the framed unit itself, but hardware costs can add up quickly too. Decide if you really need to go fancy with your hardware. If you really need something custom, be willing to pay for it. Otherwise, the standard fixtures can save you greatly! Keep in mind that painted finishes on hardware can often cost much less than metal finishes. Also, custom door hardware can be very expensive. Depending on the look you’re going for, these simple choices can help you save quite a bit! 
• Mind the threshold as well: Don’t stop at windows; consider how your door design can benefit your budget. With doors, consider that a balcony threshold can be beneficial compared to a traditional swing door with a low-threshold. Adding multi-point locking on doors can be helpful for performance (air-tightness), but often adds costs. Other considerations for doors include a basic one-panel swing vs french vs sliding vs lift-sliding vs bifold and others that all impact the price and the performance in different ways. Don’t forget to chat about both price and performance with your suppliers. Check out this threshold example from our Instagram feed. 

On any project, budget is generally a difficult discussion and an important one. We want our clients to be happy about the investment they’ve made, but we also want to deliver high-performing products for them. Value Engineering is a simple way to make smart decisions to maximize performance while reducing costs. We know that windows and doors are often zones in a home where lots of money is spent and we want to see it spent wisely. If you, or your clients, have specific questions about how they can best maximize their opening design for a more efficient home, our team would love to talk. We’ve seen a lot and would love to help you design a happier, more efficient space.

In this post, we’ll go over a few key tips for installing windows, sliding doors, and swing doors. Whether you’re updating windows in your home to modernize the look or increase energy efficiency, or you’ve got a new build going up, we hope the information we’re about to drop gives you some insight to the highlights of installation. NOTE: Any window or door you purchase should come with an installation guide, which you’ll want to read thoroughly. If we provide information here that is not in your instructions, please confirm with the manufacturer before proceeding.

While it may seem intimidating, installing a door or window is completely doable for everyone from the DIY-er to the seasoned builder. If you need a refresher on the various types of windows and doors, head back to our last post. Otherwise, grab your ‘driver, level, and some shims – here we go! 

Installing windows

There are many different kinds of windows, but the approach is generally the same. The basic steps are 1) Flash 2) Frame, 3) Install, 4) Seal, and 5) Trim. You’ve got this!

A few rules to live by:

• Do it right the first time.
• Measure, measure, and measure some more.
• If the opening is wider than 3 feet, use temporary supports.
• Moisture is your enemy.

We’ll assume you’ve already done your measuring and have prepped your framing, including checking for any water damage and replacing any wood that’s not up to the task at hand. Better to do it right at this point than to tear out all that hard work later.

Prep and preflash

First things first, prepare your opening by protecting the wood. There are a number of products you can use, but we won’t get into all the options here. Here’s a brief document that shows how to prepare an opening. However, if you’re doing a retrofit and working with replacement windows, getting the situation to look like this is not likely. You’ll just prepare and protect the opening as well as you can. 

Plumb, level, and square

Next, you’ll “dry fit” your window – pop it into place and add a few screws at the top to hold it there temporarily. Grab a couple shims and make sure the window is plumb (level along the jambs), level (from the sill), and square (corners are perfectly 90^०) on both the sash and the frame. 

A trick for measuring plumb: Measure the diagonals of the windows, and if the numbers are equal each way, you’ve arrived at plumb. The longer the level you use, the more accurate you can be.

Don’t put away your level and framing square yet – you’ll be checking and re-checking each piece throughout the whole process.

Nail flanges

Many windows will have a nail or screw flange (also called a fin), that attaches to the window jamb. Not only do they make installation pretty simple, they also do a great job keeping moisture out. While you will hear folks call these nailing flanges, do we really want to swing hammers near our windows? Screws are also a much better fastener for the long run.

You can screw right through these flanges to attach the window frame to the jambs, but first, you’ll need to cut the siding and slip in weather barrier behind the siding, wrapping around the framing for weather protection.

Next, you’ll caulk all around the opening where the flange will attach. Before you tilt the window into place, be sure you have some shims handy so you can shore up level, plumb, and square once again. Then drive your screws through the flange. 

Anchor brackets & through-frame install 

Another option that is increasingly used and very common with Euro windows is anchor bracket install. Generally installed to the interior, anchor brackets are metal strapping that is attached to the window and then fastened with screws into the jamb.  All the usual guidelines – plumb, level and square – apply. Anchor brackets are often used to install windows in thick walls like double stud walls and in high performance situations where we want the window in the middle of the insulation layer. 

Through-frame, sometimes referred to as a block-frame install, is just that – screwing through the frame to fasten the windows. Note that this is more common with operable windows like casements and tilt/turn windows. If using a through-frame approach, make sure you communicate that to your sales representative as special accommodations might be necessary with the windows. Using through-frame is less common with fixed windows as it generally means you have to remove the glazing and then re-glaze after the frame is installed. 

Fastener frequency

Always refer to the manufacturer’s instructions related to frequency of the fasteners. Also, pay special attention to fastener frequency when in high wind-load areas. More fasteners are often necessary where the wind loads are higher.

Interior jamb and sill extensions 

If your jamb turns out to be flush with the drywall inside once you’ve installed the window, lucky you. For the rest of us (especially when retrofitting an older home), jamb extensions may seem like a good option.

A jamb extension is the piece that extends the jamb (the frame of the window) along the inside depth of the wall. Not only does this clean up the window framing, it gives you a clean edge to attach the casing. 

Sill extensions build out the sill area and give you a smooth line, whether you’ve opted for a deep window frame or not. If you’ve chosen not to have a substantial window sill, this may only extend to the edge of the window trim; otherwise, it can be as deep as you’d like it.

Pro tip: We recommend against interior jamb and sill extensions because it limits access to the rough opening gap for insulation and air sealing. If you do go for it, it is often easier to build and install these extensions onsite. Also, we recommend taping the interior all the way around to the jamb to complete the air barrier. Please contact us for more information on this. 

Exterior finishing

On the exterior of the building, you’ll add your exterior casing, fasten that into place, then caulk all the way around. Install your drip cap over the window with some caulking, slipping the top edge just beneath the siding. Secure that drip cap to the top of the window casing.

Inside, fill any gaps between the window jambs and framing elements with loosely packed fiberglass insulation or a window foam. Then you’re on to a final caulk (and ideally tape) on the flange and painting.

Exterior frame extensions and sill are also available, which create a different look but also help to improve the performance of the wall overall. Passive House would say to put the window in the center of the insulation layer to get the best overall wall performance (window and walls collectively). An “innie” install makes things a bit trickier for detailing. Exterior sills and frame extensions help reduce some of the brain damage of these details. Again, please contact us for more information on these options. 

Installing sliding doors

Sliding doors are great. All that added light, plus they don’t require the interior clearspace a traditional swing door needs to swing open. What’s not to love? 

When installing a sliding door, the key pieces to pay attention to are where and how the door meets the floor and getting everything super duper leveled up to keep that sliding action smooth for years to come. If you’re doing your project with us, we’ll talk through all the micro details up front so the installation process is as seamless as possible.

There are a couple options related to the floor detail, and specifically to the threshold. Give us a call to discuss options like FASTrack where the sliding door actually embeds into the concrete floor providing a super clean look. Note that there are thermal bridging considerations related to these types of systems. 

Plumb, level, and square

Just as with your windows, taking the time to get plumb, level, and square straight will save you a host of headaches down the road. Since sliding doors are usually bigger than windows, small degrees add up and can mean your door will sag, stick, or even drift open and closed. 

We’ll add another term to this: “True.” True is your double confirmation: If plumb, level, and square are right on one side but ever so slightly sloppy on the other, you’re not true. Both sides of the door need to be plumb, level, and square to be true.

Installing swing doors

If we haven’t hammered this home enough yet, plumb, level, and square are operative words when it comes to doors, too. When installing a door, shims will start to feel like your right hand. This is most important on the hinge side of the door. One key thing to keep track of is how high off the ground the door hangs – you don’t want your crew arrive to install flooring and find out said flooring is taller than the bottom of the door sash/slab, making the door impossible to open.

Euro doors: The sash condition

It is very important to remember that European doors have very little clearance between the bottom of the sash of the door and the bottom of the threshold – generally less than a half inch. What that means is wood flooring installed after the door at ¾” will prevent an inswing door from opening. Make sure to accommodate the finished floor height relative to the door when selecting and installing doors.  

Brick mould and other trim considerations

Pre-hung exterior doors often have brick mould attached – an additional piece of exterior trim (wood, vinyl, whatever your door frame is made of) designed to cleanly overlay a brick exterior and produce a finished look. It doesn’t matter whether or not you actually have a brick exterior – this is just the name the piece comes with. 

Because brick mould makes it difficult to access the rough opening gap, to insulate and air/weather seal around the doors, we often recommend against using it and instead finish the door trim in the field. 

A quick note on installing Euro balcony doors

Balcony doors are essentially a window installation. What sets a balcony door apart is that you have to lift your feet to step over the bottom of the frame – the threshold is not flush with the floor. Not great for high-traffic areas, but it can save you a few bucks where it counts (more here). Plumb, level, square, weatherproofing, and off you go.

Wrapping it up

We hope you found some answers to your burning questions about installing windows and doors in your building. There’s a lot of information out there, and the specific product you get will come with its own installation guide. We’re here to help point you in the direction of some of the tried-and-true products we recommend (like our windows & doors or weather barriers), and we’re always happy to chat about your project. You can get in touch with us here.

Knock knock.
Who’s there?
Harry.
Harry who?
… Harry up and answer the door so we can talk about that big hole in your building!

There are lots of things we geek out about over here, and gaping spaces in buildings get our full attention. First-world countries have come a long way since the Three Little Pigs style of building, and we’ve learned a few things about thermodynamics. 

If you were to take a gander at the headlines for some of our other blog posts, you might guess (correctly) that we’re a little bit obsessed with thermal performance. Keeping heat in and out – consistently – is a big deal no matter whether we’re talking about a hotel, an office complex, or your own home. Of course, it goes beyond comfort: maintaining temperatures the right way can have a big impact on your wallet.

If you’re putting in the effort (and money) to insulate your home well and mitigate heat loss and thermal bridging, it sure makes a lot of sense to peer into the situation created by your windows and doors. 

Let’s look in to windows first.

Windows

Windows occupy, on average, 20% of wall space. But they’re responsible for more heat transfer per square foot than any other surface in your home. So if you’ve been patting yourself on the back for a job well done with insulation and think you can make sacrifices on the windows, sorry folks – windows are worth the investment.

There needn’t be a battle between letting the light in and settling for a closed-in space. Fortunately, there are some great products out there that let you create both Instagram-worthy spaces and the cost savings of a well-insulated environment.

Here are a few things to ask yourself when shopping for windows:

Let’s fling open the sash, shall we?

US windows vs. European windows

We’ll just get this out of the way first: If you’re new to window shopping, you may be confused by the whole US- vs. Euro-style window thing. In Europe, energy costs a whole lot more, so their windows tend to be extra energy efficient. This is accomplished in many ways, from high-performance frames and glass, to a higher quality and attention to detail. Even the way they open is designed to maximize energy efficiency.

European-style windows are…

American windows are…

Here at AE Building, we’re partial to European-style windows that are made in the USA. 

Types of windows

Functionality and durability should be considered right up there with energy efficiency. That includes the material used, how the window will open, and what you need the window to do for you (let the light in, let air in, or even potentially let people out).

Fixed / Picture Windows

These windows are called fixed because – surprise surprise – they don’t open. If you want light but don’t need airflow, these windows are a simple (and less costly) way to go. Fixed windows usually perform better than operable windows as well, both thermally and in terms of air infiltration.

Tilt and Turn Windows

These dual-functioning windows have hinges both at the bottom (so you can tilt it open at the top) and the side (to swing the window open). They’re more thermally efficient, so they’re popular in Europe, and can be more expensive. Note that the turn/swing function is to the inside and not to the outside like typical US-style casement windows with a crank handle. 

Casement Windows

Casement windows are usually rectangular windows that are tall and narrow. They are hinged on one side of the frame and the other side has a cranking mechanism to open the window for ventilation. They open outward.

Hopper 

Hopper windows have a hinge on the bottom that allows the top edge to tilt or open into the room a few inches. They’re usually opened with a handle at the top of the sash and can be difficult to reach on tall windows.

Awnings

Awning windows are similar to hopper windows, except the hinge is on the top and they open to the outside from the bottom of the sash.

Horizontal sliding windows

Sliding windows slide open on a horizontal track. We generally steer our clients away from sliders and hungs because their air infiltration rates tend to be not as great (due to the open seam around the operable portion of the windows). However, there are times when sliders and hungs are a better choice. Talk to us if you need help deciding!

Single-Hung vs. Double-Hung

Where a double-hung window lets you open both sashes, top and bottom, a single-hung window only opens on the top or bottom. Here again, we try to avoid these due to the air infiltration rates, although hung windows can be advantageous where you don’t want a tilt/turn intruding into your space or a casement window opening out to a deck. There are also historical considerations with hung windows as they were the primary option for operation in older buildings.

A few definitions

NFRC = National Fenestration Rating Council

This independent, third-party certification agency assigns specific energy efficiency measures to complete window system, from frame to glass. (“Fenestration” has to do with windows and doors – if you skipped fifth grade or Shakespeare class, “defenestration” is to be thrown out of a window). 

U-factor / U-value

U-factor measures how well a window prevents heat from moving through the window’s materials – in or out. The lower the U-value, the less heat is lost in winter. These ratings generally fall between 0.20 and 1.20, with the higher rating being, say, a single-glazed window with aluminum frames, while a triple-glazed window might get a rating of 0.20 and even lower depending on the gas that used within the glass unit. These days, you can get quad pane glass which can run even lower – into 0.10 +/- U-values.

Visible Transmittance (VT) 

This one’s simple enough: Visible Transmittance measures how much natural light is able to pass through the window. It’s influenced by the number of panes and glass coatings.

Solar Heat Gain Coefficient (SHGC)

A number between 0 and 1, the SHGC looks at solar radiation transmitted through a window or door. The lower the number, the less solar heat it transmits (= more shading). Some people rely on a center-of-glass or glass-only SHGC, which will give a higher number. Full window values include the frame, which has no solar heat gain. The direction your window faces, whether or not it’s shaded, and your climate zone will drive the optimal SHGC for your windows. For example, in colder climates, you want to collect solar heat on the south elevation of the home and block it on your west elevation to minimize overheating in the summer.

Energy Star Certification

Energy Star® bases its certification on U-factor and SHGC ratings for four different climate zones. Learn more here >

Doors

Now that we’ve got a handle on windows, let’s cover the next gaping hole in your building. Entry doors, interior doors, wood, steel, vinyl, with glass or without, one lock or many… When it comes to doors, you’ve got options.

US doors vs. European doors

Notes on European doors:

Notes on American doors:

Types of doors

Balcony swing doors 

Balcony doors are a popular choice for accessing exterior living spaces like… balconies (go figure, right?). Because they have a higher threshold, they are generally not used as main entry or in high-traffic doorways.

Standard US-style and Euro-style swing doors with a low threshold

For a quick mental picture of a swing door, recall any old Western movie scene where a man with spurs and chaps bursts through the saloon doors. The in-and-out swing of those doors is what gives these hinged doors their name. Thankfully, we’re looking at much more elegant and airtight solutions these days (for starters: hinges, not springs).

Lift and slide

You’re familiar with sliding doors, and the “lift and slide” door takes things to the next level. The “lift” action here utilizes a system of levers and wheels to lift the door up from its position flush against the floor/seal and move with little friction across an internal track. The lift function lifts the door out of an air seal and slides it open. Lift-slide doors generally seal better than typical US-style sliding doors.

For a closer look, check out our Advantage Classic or Mira lines, available as windows and doors.

Tilt and glide 

Tilt and glide doors slide open, with the added flexibility of tilting open at the top for ventilation. The advantage of this tilt is that it’s secure when tilted – kids stay inside, animals stay outside (or inside), and the door remains locked.

For a closer look, check out our Tyrol Line.

A note on multipoint locking

As the primary point of entry for your building, doors generally have a higher security threshold than windows. Multipoint locks are more common in European doors and usually include a deadbolt, live latch, and several additional locking pins around the door sash.

Wrapping it up

Hopefully this primer has helped clarify some of your questions and given you some ideas about what kind of window or door is best for your unique scenario. We’re proud to provide made in the US, European-style windows and doors that are Passive House certified. We’re here if you have any questions, so don’t hesitate to reach out.

In our next post, we’ll get into installation methods. Stay tuned!