Replacing Double Pane vs. Single Pane Glass

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When it comes to home improvements, replacing your windows is one of the biggest and most complicated projects a homeowner can undertake. There are an enormous variety of window options to choose from with various window costs and benefits, so making your selection can be overwhelming and far from straightforward. Among the many choices for replacement window panes are both single and double paned glass, each with its own properties and benefits. Here we outline the major differences between single and double paned glass, ways you can expedite the replacement process, and several other pieces of information that will help you make an informed decision when the time to replace your windows comes.

New Windows Closeup

Choosing your replacement windows

The first step in the window replacement process is choosing your new window panes. Among the factors to consider here are cost, visual appeal, comfort, and energy efficiency of the windows.

Some homeowners who have single paned glass opt to stick with the same kind of window during replacement for the sake of continuity and simplicity. Other homes with a traditional aesthetic (Victorian, Colonial, or Tudor style homes in particular) are expected to keep window panes and frames in the style of their era, so upgrading to double glazing is either extremely complicated and expensive or impossible in these instances.

bay windows on city street

Many environmentally conscious professionals recommend double paned windows, which save homeowners money over time by reducing energy usage throughout the home. However, quality double paned windows are more complicated to construct, and therefore cost more to purchase and install. Other benefits of double paned glass include noise reducing qualities (ideal for urban homes) and insulation (one of the top reason homeowners in colder climates opt for double—or even triple—glazed windows).

Although the benefits of double glazing are undeniable, cost is often a mitigating factor for many homeowners. In order to achieve the maximum energy benefits given by double paned windows, you will need to replace every window in your home to the same standard—a time-consuming and expensive project.

Single to double pane—and vice versa

If you decide to change the type and style of your window panes during your window replacement, it is important to remember that window sizes can and do vary significantly. In addition to new glass, your window replacement may well require new frames, casings, and other window parts to make everything work cohesively as a unit. Generally speaking, double paned glass frames are deeper than single paned frames because they need to accommodate two layers of glass and a middle layer of insulating gas and/or desiccant. Some frame materials work better with energy efficient windows than others, so researching your framing options will help you make your decision.


Another factor to consider when deciding whether to upgrade to double glazing is the weighting of your windows, especially if you have double hung windows. The mechanisms in these kinds of windows need equal weight distribution, so the glass in each part of the window needs to be the same.

Preparing for your window replacement

While technically, you can complete a straightforward window replacement yourself, we recommend bringing in a window professional who can get the job done quickly and safely, to the highest possible specifications. This is particularly important with windows, which can make or break the comfort levels and savings in your home.

If you decide to bring in a professional to complete your window replacement, there are a few things you can do to prepare for this home improvement project. The first and most important step is to do your research. Once you’ve decided on either single or double paned glass, you can check whether the windows you have chosen are IGUs (insulated glass units) or contain low-E (or low-emissivity, referring to the ability of a surface to absorb, reflect, and emit radiant energy) coatings.

Before ordering your replacement window panes, make sure you measure and measure again. If you need assistance with this step, these detailed instructions will help you get your measurements right. As all homeowners know, incorrect measurements can push back project completion dates and blow your budget if you’re not careful.

Some homeowners choose to expedite the window replacement process by removing the old windows themselves. If this is the case in your project, we recommend that you check the wall structure and composition surrounding your windows for stability and signs of wood rot or decay. Ask your window professionals whether you need to remove your cover strips, sashes, and casements in order for the new windows to fit into the space. This can be a big job, so allow plenty of time for this step.

As with all home renovations, it’s a good idea to stock up on sheets and cloths to cover your flooring and furniture during the messy window replacement process. Also, make sure to keep both interior and exterior areas around the windows accessible by moving furniture, if necessary, and creating a clear pathway for your window professionals.

After all is said and done, you should love your new windows. If you’ve opted for double paned glass, just make sure to check the spacers in your new panes and the seals around the units, since condensation can quickly develop between the panes if the seals are not tight and there isn’t enough desiccant in the spacers.

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