If I Had The Chance To Do It Over: Windows

There is definitely more to windows besides being a gateway for your eyes to the outside world.

Brian Wright

1/31/20264 min read

Often thought of as being your lens to the outside world, windows will no doubt play a huge part in any build. At first glance, your window decision may seem pretty cut and dry but when you really start to think about your budget, design, energy efficiency, functionality, and longevity your window decision can become quite daunting. So, let's open the curtains and put up the shade on this topic and take a look at what I think we got right and what I would do different if I had the chance to do it all over again.

The two most important reasons I wanted to build my own home were for energy efficiency and longevity. I like to do things right the first time, and when it comes to the new construction window install process, I think we did a lot of things right. Zip sheathing with liquid flashing and tape made an air- and water-tight installation with a typical new-construction window design. I am fully confident that the installation process we used will outlast the window itself. If you are interested in that process, you can see how we did it on our YouTube channel here: https://www.youtube.com/watch?v=MeTW0E7eqWo. The one thing I would do differently, however, is add trim in addition to the J-channel around the outside perimeter to ease the process of window replacement (God willing, I outlast these vinyl-made windows). This would allow window removal and replacement without having to remove any of the steel siding.

When it comes to energy efficiency, there are two schools of thought: pay up front for highly efficient quality windows and save over the long haul, or make payments over the life of a budget-friendly window with higher energy costs down the road. There are many things to consider concerning window performance, but I want to focus on two specifics that affect performance and price: the type of window (single-hung vs double-hung vs casement) and U-factor. The first window decision we made was to go with single-hung on the majority of our windows. On a single-hung window, only the bottom sash moves, whereas on a double-hung window, both the top and bottom sashes move. For us, the decision to eliminate the double-hung window was easy, for a couple of reasons. I can count on one hand how many times I have cleaned the outside top half of a window during my life. So, the convenience of having that top sash slide down and tip in was not a factor. Also, when it comes to air leakage, a double window is going to leak more, and you guessed it, probably at least twice as much as a single hung window. For those reasons alone, double hung was out. Now, as for casement windows, you pay more than you would for a comparable single-hung window. Casement windows typically crank open, so there is more hardware involved compared to a single-hung window. However, casement windows, also crank closed and seal much better than sliding single-hung sash windows, which cuts back on air infiltration. So, why didn't we choose casement? One simple explanation: cost. Casement windows were almost double the cost (we spent almost $9000 for single-hung), and it simply wasn't in the budget.

Now, as far as U-factor goes, that is the way window manufacturers put an R-value on their product. My guess is that when you do the conversion from a U-factor to an R-value, it can be so low that it might scare some people back into cave living. Here is the formula: R-value = 1 / U-factor. So, in the case of our windows, which have a U-factor of 0.27, we ended up with an R-value of 3.7. Now that may not sound awful for one little window, but when you add up the total area of all the windows, it quickly compounds. While I have the calculator out, lets crunch our numbers: 14 windows x an area of 12.5 sq. ft. = 175 sq. ft. That is equivalent to almost 5.5 sheets of 4x8 zip sheathing with only 1 inch of insulation behind it. For comparison purposes, our walls are insulated to R-29 with Rockwool products. I told you it is scary to think about! So, what would I recommend? Get the highest U-factor windows your budget will allow. While I am happy with the way our windows turned out, if I had a do-over, I would definitely carve out a little more in the budget for a higher insulation factor.

So, the next time your view looks like mine right now outside your window, be glad that you put all that time, money, and effort into your window decision.