It’s hard to give a general answer that will work for everyone’s house, because there are too many variables to consider. Still, without knowing anything about your house, and working solely from your question, I will try to answer your question by considering what the important factors are:
How old are the windows and doors in your house today?
Even under the best circumstances, a house will age. Time just works on it, and Mother Nature is constantly trying to “take it back” into her tender mercies, so to speak. As the house ages, so too to all of its components. Properly protected and cared for, we can expect the typical house in the Puget Sound – where most house are made on the basis of a wood frame – to last a lifetime. Over the past century, the quality of homes varied back and forth as the decades passed by. It’s hard to define each exact time period, but one springs to mind. In the 1920s, homes seemed to be made more simply and more solidly. Wood was in plentiful supply then, so why not make it from wood. Back then, if you had some basic carpentry skills, you could buy a house plan from a catalog, and off you go! Today, of course, homes are far more complex, and there are laws around the construction of them. Not anyone can roll up their sleeves today and build their own home.
If your window frames – I say ‘frames’ because many panes have long been replaced, perhaps several times – are a hundred years old, it is very likely they are not keeping the warm air in, or the elements out. Over that time, the very shape of your house will have changed, and the window frame will have changed shape with it. In addition, as wood ages, it warps slightly. The older it is, the more it is likely to have warped. It’s not a huge difference, but more a question of a slight change that allows air to draft in where there was an almost perfect seal when the house was built. In many cases, the mere replacement of windows in a house will vastly improve its energy efficiency. In addition – and this is something I personally noticed in my home when I replaced our living room windows – the street and ambient noise levels dropped significantly. A good night’s sleep is worth something.
Are the window frames decaying or broken?
Windows and window frames have to perform several duties in your house. In addition to that, they have actual moving parts. If you open and close a window several times a day, and the window survives baking summer heat and freezing winter cold, over many decades, and still be expected to deliver the perfect insulation from the elements, you can see how challenging window design and construction can be. Thankfully, today’s modern manufacturing techniques produce far superior quality and for less money. The technology that goes into windows is extraordinary.
If you are replacing wood frame windows, and you’ve found that the wood is actually crumbling to the touch, then definitely, replacement will make a huge difference to your house.
Another point to consider, if your wood frame windows are disintegrating to that degree, there may be a wood problem beyond the window frame itself. Often, a window might be in better shape than the wood around it. That is, part of the house. And that brings me to the next topic: The inspection.
Getting your windows and doors inspected
It’s always good to know exactly where you are before you head out on a journey. Most windows and doors companies will pay you a visit if they understand you are serious about the work you are planning doing. Most such providers know that must invest a certain portion of their business time simply visiting new prospects, and you can likely get a solid inspection and work estimate from your provider either at no cost, or at a nominal price that is usually offset later against any work you give them. The beauty of getting the windows inspected is this: Most experienced contractors know that if they find a problem, they are likely to be first in line to provide a solution to it. For that reason alone, it is easy to believe, they will be eager to find a problem if there is one. If there is, indeed, a problem that goes beyond the actual window (or door), it’s good to find out now, before you commit to any big window project. If it does turn out to be a big repair, you might need time to muster the cash. To find such a problem in the middle of a window replacement project might put you in a difficult position. Know early.
The best time of year to replace windows or doors
Any contract work going on in your home has the potential for discomfort, you could say. Even though the time a window is gone and the new one installed is relatively short, if you are replacing your windows in the depths of winter and there’s an ice storm approaching, you need to plan for that. With a whole window and its frame gone from your living room, that living room will get cold quickly. For that reason, it’s good to plan ahead. If you don’t have to worry about kids getting frostbite while the house goes into a deep freeze, the winter is actually a great time to get your windows replaced, and for two distinct reasons (1) window installation companies tend to have more time, and therefore probably more attractive rates, in the winter because they want to hold on to their ‘summer teams’ with work all year round, and (2) you’ll know very quickly if there are any insulation issues post-installation!
Check for seasonal rebates too. Just like the installers, the windows manufacturers themselves like to keep their factories humming evenly all year long. Much of their cost is fixed, so they’re burning cash whether the factory is producing or not, so they often off special deals to their installers – and you the homeowner – if inclement weather does not bother you.