How much do double pane windows cost? Experts explain why it's worth it

If you're looking to find out how much double pane windows cost, this is for you. Double-pane or double-glazed windows are well worth it: because better-insulated windows are critical to a well-insulated house which can ultimately, reduce energy bills. 

Saying that, you should carefully budget for the initial expense of replacing existing single glazed windows with double panes as it is a major renovation project.

There are several different window types out there, depending on the style and age of your home. Most of them are suitable for replacement with double-pane versions, although you should always speak to the manufacturer first. The following recommendations from structural and window experts should give you a good idea of the potential cost of installing double pane windows throughout your home and, the best way to go about it. 

How much do double pane windows cost?

First, it's worth mentioning that most new window installs these days will be at least double-pane and filled with an inert, harmless gas such as argon in order to improve the windows' thermal insulation properties. When working out the cost of double pane windows, there are several factors to consider. As Ben Neely, Owner of Riverbend Homes, explains, 'double-pane window pricing vary greatly by size and by frame materials. Depending on climate and local codes you can purchase windows made with vinyl, thermally broken aluminum, fiberglass, and even steel. These windows can vary greatly but a good rule of thumb I often go by is about $625 per standard 3’x6’ window, or, $30-35 per square foot of window should give you about what a mid-high range window should cost from an American supplier.

If you want a wider estimate, Volodymyr Barabakh, the Co-Founder and Project Director of building contractors Structural Beam, says that you can 'expect to pay around $385-850 to replace a double pane window.' To narrow down this number to a more precise figure, Rose Reif, a window specialist from the Raleigh, North Carolina-based Window Works Co., recommends considering the following factors:

• The material the window is made of (wood being least expensive and Fiberglass being most expensive)
• The type of window (single-hungs will be least expensive, and casement and awning windows will be the most expensive)
• The installation process (existing frame installation will be less expensive than full frame replacement).

Ultimately, the full cost of double-pane windows will vary greatly, ranging from a few hundred to a few thousand. The cost obviously will also depend on whether you already have double pane windows and are replacing one or two, or whether you are replacing all of the windows in a home as part of a house renovation project. 

How much does it cost to double glaze a house?

It may make more sense to budget double pane windows costs by considering the size of your home rather than trying to work out precise costs per square foot of window. According to Barabakh, 'to double glaze an average 3 bedroom house you will want to budget at least $3,000. Though, depending on location, number of windows, and window type this price could increase to $10,000.'

This is a substantial cost, but Barabakh points out that installing double pane windows is generally worth it because 'glazed windows add value to a house when selling and also save you money on heating bills as they keep your home better insulated.' Double-glazing a house is also the way to go if you're trying to find how to stop condensation on windows, which can cause damp and mold that will age your existing quicker anyway.  

Should you replace all your windows at the same time?

Given the typically high cost of double pane windows, do you have to replace them all at once, or can you replace your windows gradually? Rose Reif advises that 'you can certainly replace windows in batches if that is better for your budget or the timing of other home remodeling projects.' However, 'many people choose to replace all at once to reduce labor costs, to ensure continuity between all the windows, and to increase their home's energy efficiency.'

Neely agrees that for those homeowners who are trying to find ways to save energy at home and therefore, money on heating bills, 'it’s often the best idea just to replace all of them at once, because your home is only as insulated as the weakest link.' Replacing just one or two windows when you have eight won't make any difference to a drafty house.  

There is another reason why you should consider replacing all your windows for double-pane ones at once. Barabakh explains that 'replacing windows requires paperwork so getting them all done in one reduces this. It will also save you time, in the long run, to replace them all at once instead of replacing them individually when needed. Getting a contractor in to do the full job in a couple of days will allow you peace of mind that the job is done and won't need returning to.'

There is an overwhelming argument for replacing all your windows at the same time. Obviously, this has to be financially viable, and if window replacement is just one item on a long list of renovations, you'll have to make the decision based on what's the most important project to complete first. 

There is one more reason why you may want to replace all your windows at the same time, even though it will cost more. Neely warns homeowners that 'Right now, windows are some of the toughest commodities to get delivered to a job, so if you’re planning on replacing windows in the next two years it’s best to just do them all at once.' 

The pandemic has affected the availability of both materials and labor, so replacing windows gradually may significantly prolong your project, possibly costing more in the longer run. 

How long will a double-pane window last?

According to Barabakh, 'a freshly replaced double glazed window should last around 20 years if installed correctly. Different materials may hold up differently and it is good to ask your contractor how long you can expect them to last to ensure you are on the same page.'

You also will need to think about how much maintenance you're prepared to do. Timber windows will require more upkeep than fiberglass, even if they are cheaper initially. Regular cleaning with the best window cleaning products and repainting the frames will prolong the lifespan of your windows.