Deciding on tiny house windows - what are the factors?
I'm still shopping around for the best windows for my house. There are many important factors to consider when choosing windows. Below are thoughts on some of my primary concerns.
Window R-values can range from effectively zero, to something ridiculously high like R20 with triple-pane glass, other glass enhancements like films and glazings, plus a much more insulated frame made from better materials. I certainly can't afford the top of the line, but I do care a lot about efficiency. For my tiny house, I'm looking at double pane windows, with at least the basic Low-E coating, and a frame material that will hold up over time, and is a reasonable insulator.
Strength & durability
Wood windows, though beautiful, are expensive and require much more maintenance than those made from other materials. For this reason, I'm not considering all-wood windows for my tiny house.
Vinyl is thin and flexible, and it expands and contracts a lot with changes in temperature. All this leads to a window that is inexpensive, but weaker and less durable -- one which will become ill-fitting and less efficient as it ages.
Fiberglass and aluminum are much stronger, more rigid and more durable. These materials provide a stronger frame that won't warp over time, and generally feel sturdier, with smoother operation and tighter fitting seals. I'm currently leaning towards fiberglass if I feel I can afford it.
I think at least some level of Low-E coating is standard these days and is a must if you care at all about energy efficiency.
To temper or not to temper? That is the real question. I know a lot of tiny house builders who always use tempered glass. In theory this protects the glass from breaking during the inevitable bumps and vibrations of travel. But is it absolutely necessary? I really don't know. I know plenty of people who have not used tempered glass windows, and they had no breakage problems during travel. Tempered glass can add a considerable amount to the cost of a window, especially at larger sizes.
So what do you think about tempered glass? I'd love to hear your thoughts on if and why tempered glass is necessary in tiny houses (the mobile kind, on trailers).
This is a given: Good windows are expensive. Many would choose Jeld-Wen windows from their local Big Box store. They'd be reasonably efficient and at a good price. They would be vinyl and they'd be white like everyone else's vinyl windows. The sizes available would be limited. I surely could have saved myself a good deal of money if I had designing my house to use standard window sizes, and not included a ridiculous number of windows in such a small space (10 windows total). But the house was designed for specific needs, so sizes and placement of each window had to correspond to the floorplan layout and particular use of each interior space. Plus, I felt I just needed as much of an open feel as possible, to avoid claustrophobia while inside. So, that being the case, I will pay for my decisions with cold hard cash.
In general, vinyl windows are cheapest. Fiberglass is considerably more expensive, but usually less than an all-wood window. Aluminum is similarly priced (or more expensive) than fiberglass, though not as often used for residential windows and is a very poor insulator. All-wood or aluminum clad wood is usually the most expensive typical window frame material. When you get into the really high-end energy efficient windows, then they are often made from several different materials...but let's not go into detail there.
So, how does this all break down in making my own window choice?
Top on my list so far is Integrity fiberglass windows by Marvin. They are a big step up from standard vinyl windows, in my opinion. They meet Energy Star efficiency standards and their fiberglass material is very rigid, doesn't expand/contract like vinyl, and the finish is maintenance-free. The are smooth operating and come in several colors. Real wood interiors are also an option.
Another brand I've recently come across is Hurd. Their H3 windows are a unique mix of wood interior, with a vinyl and aluminum frame, blending the best of all 3 materials. They are a bit more expensive, but offer additional energy efficiency (ultra R) upgrades and are cheaper than comparable aluminum clad wood windows from other companies, like the Pella ProLine. They also have a lot of nice exterior color choices, plus the real wood interior would be a nice touch.
I've also explored Milgard as an option. They seem to make reasonably nice, affordable windows (mostly vinyl), though they technically don't operate in Iowa, and so buying from them would mean no service available if there were any problems and warranty repairs needed.