Adding Windows to a Metal Building: 4 Essential Things to Consider

Adding windows to your metal building might be the single best thing you can do to improve its quality and utility.

Not only do windows bring in natural light, but they also help heat your metal building, improve ventilation, and make it more energy-efficient.

But before you get too excited, you should know that installing windows in your metal building takes some thought and planning. Below you will find 4 things you absolutely must consider if you are serious about customizing your metal building with windows.

What type of windows do I want?

The most common types of windows used in metal buildings are slimline, single hung, and horizontal sliding.


Chosen for their minimalist design — which fits nicely in most metal buildings — slimline windows have a slight frame and bring in the most natural light.

Single Hung

A two-sash window offers both natural light and ventilation, where the top sash is fixed but the bottom one can slide upwards.

Horizontal Slide

A Horizontal Slide is similar to a Single Hung window, but the sash slides across (not up and down).

It is worth thinking about this because although installing metal building windows is pretty straightforward, paying to have it done, undone, and then redone because you chose the wrong type will waste your time and money!

Once you know what type of windows you want, you’ll need to think about the style of frame you want too. Vinyl? Aluminum? Self-framing or self-flashing? It is worth taking the time to properly research the different options and speaking to your contractor about what would be best for your building.

Where are they going to go?

There are a few restrictions on where you can place windows in metal buildings. For example, you cannot place a window where there is already a support column or x-bracing in place.

These restrictions apply if your metal building is already constructed or if you’re thinking about windows in a metal building that’s not yet built. Tell your building company where you want your windows, and they can make sure nothing’s going to obstruct them.

Secondly, you should avoid really big windows — opting for a higher number of smaller windows instead. Why? Because your window frames will be installed into the metal wall of your building, and while windows are great for a lot of things, supporting weight is not one of them!

A couple of useful tips to finish up here: if you want to add light, you should go for a south-facing window and if you want ventilation, add a window on the opposite side of the door.

How can I prevent leaks?

You want your windows to be leakproof, right? By caulking your windows inside and out, you can seal them against the elements and get the maximum benefit from your metal building.

Here, there are two things to bear in mind. 

One: make sure you choose the right kind of caulk (exterior ones are more hardy, while interior ones are strictly non-toxic and far less noticeable). 

Two: research the proper technique if you are doing it yourself so you get a smooth finish. Bob Vila has an excellent guide to help first-time caulkers to do a professional-looking job.

Am I really the right person for the job?

Okay, no one is knocking your DIY skills here. But installing windows on metal buildings is likely to test even the most experienced weekend handymen and handywomen — and it’s certainly not recommended for first-time DIY-ers!Talk to a professional (like California All Steel) about what you want and why. That’s the best way to avoid costly mistakes, and fast-track yourself to satisfying results.