How Big Should Your Shed Windows Be?

Backyard shed

Are you planning on building your own shed or buying a prefabricated one? How about installing or replacing existing windows? You must consider and observe several factors that affect the measurements.

If your shed aims for storage purposes, you need small windows to allow light and security, which measurement 12×12 inches to 18×18 inches. You can also use transom windows about 10 inches tall. For ventilation purposes, pick large windows that measure about 14×21 to 30×36 inches.

In this article, we will discuss how to add windows to your shed, the things you need to know about windows and doors, and how to measure for a window replacement.


The Importance of Adding Windows to Your Shed

When adding windows in your shed, you need to determine the type of window you want, whether it be a replacement or a new construction. Measure the size of the windows before you leave an opening in your shed’s walls. The measurement of the window openings should be paralleled to the size of the window to install.

A window for a shed is important for proper ventilation. Without it, the structure will probably be hot and suffocating. Plus, it also provides you a visual outside the shed.

Before you add windows to your shed, keep the main factors you should consider in mind. These include the shed window’s measurement, type of window, and space available on the walls to install it. Make sure you have measured the window you plan to add to your shed to avoid miscalculations of the opening you will provide.

There are two types of windows you can incorporate into the frame of your house: replacement and new construction windows. Read along to decide which one to use.

  • Replacement windows

As the name suggests, replacement windows are replacements of the windows you currently have in your shed. The measurement of this kind of window is patterned to the size of the existing window opening. Unlike new construction windows, you can replace old windows easily without removing the frame.

  • New construction windows

New construction windows are for newly built sheds. The studs or nailing flange of this window are exposed on the outside of the shed. When installing one, you should nail the window to the frame, which requires a lot of work compared to replacement windows.


How to Measure Windows and Opening for a Shed

We recommend you go to the store and look for the kind of window you are planning to use. Measure its length, width, and height. The measurements you obtain will help determine the exact opening you need to leave for the windows.

Now, let’s say your window is 24 inches wide x 36  inches tall. Your window opening should also be 24×36 inches. You won’t need any extensions for the window as it should perfectly fit in the opening.

Some shed windows are also installed on the upper part of the door. Here’s how to prepare the needed measurement for this. Let’s, for example, that the door is 80 inches tall. Subtract the height of your window to that of the door. That equals 44 inches, which is the height of the window’s base from the ground.

Remove half an inch from 44 inches. That will give you 43.5 for the bottom area of the window. Then, add 36 inches for your window’s header.


Things to Consider When Measuring for Window Replacement

If you are planning a window replacement for your shed, measure the width and height of the window currently installed on its walls. These measurements will serve as a blueprint when buying windows. Window customizations are ideal to suit the size of windows to be installed in the frame.

  • Width

Always remember to set your tape measure from jamb to jamb when measuring the width needed for your window replacement. Beware of the confusing parts of the windows, like parting beads, which you might mistake for jambs, which can affect your measurements. Make sure you are measuring it against the right jamb to the left jamb and vice versa.

The parting bead of the double-hung windows is found in between the sashes. This is removed during the replacement of the windows. First, recognize the type of window you have so you can determine where to locate the jamb.

Start the measurement by using the small measurements. Ensure you get the width of the upper part, base, and center of the window.

  • Height

In measuring the height, position your tape measure on the topmost part of the sill to the top part of the jamb. The stool can confuse you from the sill as both are found at the same level, underneath the window. The sill is located underneath the window, where it sits while the stool is the molding on the outer area of the window, where you can put plants.

As with the width, use the smallest measurement when measuring the left, right, and center parts of the window.

  • Reduce some measurements

Once you’ve measured all of the parts as instructed, remove about ½ inch of its height and ¼ for the width to prevent you from pushing the replacement windows to fit into the openings. Making the measurements smaller helps fix the windows easily as it contains extra spaces. The measurement should fit in the square, level, and plumb of the windows.

  • Consult window manufacturers

Even though you already have the exact measurements of your window opening, some manufacturers will offer you fixed or standard sizes of windows, meaning you’ll purchase pre-made windows, which you must adapt to the measurements you have. Choose smaller sizes from the noted measurements so they will easily fit the frame of your shed.

You can look for manufacturers that allow you to customize the windows to your measurement and design.


Things You Need to Know About Windows for Sheds

Before you buy windows and doors for your shed, know whether you want to retrofit or modify the walls to install the windows. Check out the types of windows and doors that you may want to put as they affect the security and outdoor exposure of the things inside your shed. You can apply weather-proofing mechanisms to manage water leakages through the openings.

There are several aspects you must consider when installing doors and windows in your shed, including:


Retrofitting and Modifications

Retrofitting is another term for replacement windows. It involves changing the existing windows for new ones without removing the other elements installed. This method is common knowledge to most handymen and does not require you to dislocate the frames.

A modification or customization, on the other hand, involves adding something that doesn’t exist on the original product you bought. An example of such is when your shed has no windows and you created an opening to install one. A handyman may propose to modify the wood materials as other options may be easier to cut than metal, for instance.


Windows Selection

If you choose the retrofitting of windows, the manufacturer can only offer you a limited variety of windows. As it is only to replace existing windows, you are not free to choose another design and size of window. For instance, if you purchased a prefabricated shed, it will still leave you with limited options when changing the windows as it already has a window or opening. You need to fit in the replacement window to the current one.

On the other hand, you can pick any kind of window and install it in a customized shed. The options are limitless, and you can ensure durable and new frames to install on the opening of the shed. Choose aluminum or vinyl frames as those are weather-resistant.

Some sheds are used by homeowners as storage. Thus, they prefer installing non-operable windows to prevent intrusions whenever they are not around. This kind of window cannot be opened and can secure your valuables.

If you plan on staying in your shed for some time, you better install an operable window for proper ventilation. The type of windows you may want to associate in your shed is up to you. Make sure it fits the idea and purpose of the structure.


Choose Durable Windows

Since windows are transparent and you can see what’s inside of the shed, the place is prone to theft. Some windows are easy to break, while some are durable enough to withstand possible break-ins. If you seek windows that are hard to damage, choose some with laminated and tempered glass as these are tested to combat intrusions.


Exposure Damages

Windows serve as an opening for a shed. They allow outdoor elements that may affect your equipment and tools inside. Whenever it rains, the windows may leak water inside the shed and wet your valuables. Damage may be inflicted, especially to the electric-powered equipment you stored in the shed.

Sunlight and heat are other components to watch out for. These may cause moisture to your equipment and damage it over time. Thus, before you install a window, ensure that this won’t affect the purpose of your shed.



The main goal of installing a window in your shed is to provide ventilation. Aside from the air circulation, sunlight access will not only deliver disadvantages but a great advantage for plants. If you plan on making your shed an area for workspace or gatherings, you might as well install an operable window on it.


Shed Doors

Apart from windows, you also need to choose the type of door you want to install in your shed. There are several kinds of doors you can pick from, and these are the following.

  • Bifold Doors

These kinds of doors are also known as folding sliding doors. Bifold doors open through a folding in and out movement. The doors have hinges connecting one part of the door to another, allowing it to fold. You can slide it on one side of the opening area after you’ve folded the door.

  • Sliding Doors

As the name suggests, you can open this kind of door by sliding it on one side. It is ideal for sheds with limited space as you don’t need to reserve a space to open the door.

  • Roll-up Doors

The best example of this type of door is the common roll-up doors you can see in garages. These are usually made of PVC, steel, or aluminum, which are all durable materials. Roll-up doors are ideal for sheds intended to store items, where you can keep your big-sized equipment due to the huge opening they provide.

Just like windows, doors contribute to the security and resistance of your shed against the weather. Choose concealed hinges for your door as they can provide strong security. This type of hinge is difficult to break, which is ideal to prevent theft.

Strap hinges are also an option, although they can’t assure you good security. They can give you ease of installation, but intruders can effortlessly take out the screw.



Shed openings are essential, and to ensure resistance to the weather, you can apply weather-proofing measures. Install door sweep and foam tapes surrounding the sides and corners of your windows. These materials help in blocking the access and leaks of water from the outside of the shed.



Windows play a huge role in ventilation and providing a view outside and inside of the shed. The size of your window matters, especially if you want to build a shed on your own or buy a prefabricated one. Whether you want to replace existing windows or install new ones, keep the proper measurements in mind so you can set your window without any drawbacks or damages.

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