How to deal with a drafty home

The leaves are falling and the overnight temperatures are falling along with them. That all brings with it the inevitable question of old drafty windows. Many homes in the Boston area either have original pulley weight windows or some incarnation of a replacement window that is long past it’s expected lifetime. They are drafty, the mechanics are shot, the seals between the glass panes may have failed, and the windows are foggy.

Many windows we come across have succumbed to all three of these issues — and then some. So, what is the best remedy? There are three main ways to deal with old leaky windows.

Replacement windows

A replacement window or window insert is a window and a frame that is installed inside the existing frame. Typically, just the two window operating sashes are removed, and the new sashes and frame are installed within that opening. The advantage to this is that most of the interior and exterior trim stays in place, speeding up the process and keeping the cost down. Virtually all the ads we see on TV are for a replacement package.

If you go this route, you will find that the replacement costs vary widely depending on what you use. The most economical window type is white vinyl inside and out — but even within those brands, there are good quality and bad quality windows. To make things more confusing, all windows installed in Massachusetts should meet the same energy standards set by code; there is something called the minimum U factor that all windows installed in the state should meet.

So, the low-cost all vinyl windows can tout that they meet the same standards as a more expensive brand, and they would not be wrong. However, the construction of the window, the hardware, and the operating mechanisms could be inferior, and that will start causing problems soon after. It is important to do your homework.

With a replacement window, the window opening will actually be a little smaller because where you had just two window sashes, you now have the frame and then the new window sashes within that opening. Some window manufacturers have narrow frames or frame kits for their windows — less expensive windows have a larger frame that make the window area substantially smaller. We encourage clients to come to the various showrooms we use to see samples of the windows and operate them to be sure they are something they want in their homes.

The replacement windows that we typically install are a step up from all vinyl; they have a wood core with a cladding on the outside. The cladding that protects the exterior of the window is fiberglass or aluminum, depending on the manufacturer. The interior of the window is exposed wood, either stained or painted. Different species of wood are available as are a variety of window hardware and finishes. This makes for a more custom look in keeping with the existing interior of the home. These windows cost more than the vinyl windows.

Another major driver of the cost of replacement windows is the installation. Older windows are a major source of lead. When most people think of lead in their homes, they think of peeling paint, but lead dust created over years of window operation is far more of a hazard. For that reason, protection and careful handling of the windows is important. We are also careful to be sure the old window pockets that surround an older window are properly insulated. Otherwise, you will still have drafts even with a new window.

New construction windows

Replacing a window with a new construction window is a step up in complexity and cost. The big difference here is that with a new construction window, you are removing the interior and exterior casings and installing the window from the outside, much like you would in a newly constructed home. The main reason we would do this type of window replacement is because of substantial rot visible to either the trim or the windowsill and frame.

There are several advantages with new construction windows. One is that you get to better see what is going on inside the walls, allowing you to address problems you would never have access to otherwise — such as rot or insulation issues. You get a bigger window and more glass area with a new construction window because you have removed the old window frame and not forced to work within it. This allows for a window at least the same size as what came out, and possibly a little bigger depending on original windows installed.

The disadvantage is cost. It is far more invasive, requires double or triple the installation time, and substantially more materials. But because you have replaced everything around the windows with new materials, it will be a longer-lasting window.

Window restoration

Finally, the option to restore a window is something we have done many times, but it’s far less common. There are two main reasons a client would opt to restore a window: they are in a historic district and it might be difficult to get permission to change them; they want to keep the architectural integrity of the home intact.

The procedure is quite laborious. The window sashes are removed and taken offsite to be repaired and reworked so they close snuggly against one another when reinstalled. Small rubber weather strip seals are installed on the sashes to ensure a tight fit. When they are ready for reinstallation, metal weather stripping bands are installed on the sides of the window frame to make for a tight fit and to allow the windows to glide up and down easily. The pulley weights are inspected and replaced if necessary. The rope that attaches the sashes to the pulley weights is replaced with a bronze chain.

The pulley itself is usually in good shape, so we just apply a lubricant. With all that TLC, the windows work better than they did when they were new. We always have a quality storm window applied to the outside of our newly refurbished windows. Even a well-restored window is still a single pane window. A quality storm window will largely give you that air pocket you need to keep the interior glass warm in the winter months.

What may surprise people is that refurbishing older windows is very similar in cost to a new replacement window insert. The materials are far less than a new window, but the labor and logistics are far more. The two tend to cancel each other out.

Mark Philben is the project development manager at Charlie Allen Renovations in Cambridge. Send your questions to [email protected]. Questions are subject to editing. Subscribe to the Globe’s free real estate newsletter — our weekly digest on buying, selling, and design — at Boston.com/address-newsletter.