Are you looking for a contractor?
Submit our quick form and get quotes now!
Table of Contents
7 min read
7 min read
Renovation tipsHow to Install a Bay Window Step-by-Step
Windows rank amongst the fundamental architectural features of a house, allowing daylight to filter in. With that in mind, bay or bow windows are a sure asset in all homes.
They’re essentially multi-purpose features, notably doubling as a reading nook, breakfast area, or lounge area (the window seat).
Moving forward with a bay window installation project requires one to be knowledgeable in construction, so if you’re a novice in the matter, recruit as many experienced individuals as you can, to lend you a helping hand with your project. With a bit of confidence and a decent skill set, we’re sure you can install the bay window of your choosing. Keep reading for step-by-step guidelines.
Source: Canva
First things first, you’ll need to determine the shape and size of the bay window you’re looking to install. If you want your bay window to be rather striking, you’ll need to build one that protrudes way out, in a sort of cantilevered fashion. Choose the angle of your window. Angles range from 45, 30, or 10 degrees; the smaller of the lot is often referred to as a bow window.
A bay window is made up of three separate window panes, which are joined to make a single, larger unit. Although the installation is similar to that of a flanged window, some significant differences should be accounted for.
We suggest asking yourself some preliminary questions prior to moving forward with such an installation project, such as: what kind of side window to use; what type of sash; and how you plan on holding the window in place. In some cases, additional support will be necessary from above or below the window, and it may be that both are required.
If you’re planning on installing a mini bay window, it likely won't require additional support. It’s also important to consider how the bay window will be finished, including whether there will be an eave above the window or whether you’ll be building or purchasing a custom-made roof.
Bear in mind that, depending on the manufacturer, you may need more or less material than listed here:
Tape measure
Drill
Sledgehammer
Level
Caulk and caulk gun
Screwdriver
Flat pry bar
Brackets
Circular saw
Window
Flashing
Roof structure
Roofing felt
Sheathing
Roofing
Roofing and finishing nails
Interior trim
Casing nails
Insulation
Once you’ve collected all of the necessary tools and materials, you can begin installing your new bay window.
Prior to cutting a hole directly in your wall, properly prepare the space in which the project will unfold. This includes removing any furniture you wish to keep dust-free or simply covering items with a tarp or two, or an old bedsheet. Also, don't forget to seal any ducts or air vents located in the room to prevent dust from seeping into them. The first step will consist of cutting the opening where your bay window will be installed.
This process will mostly depend on where in your home you plan on installing the window, the surrounding surfaces, the wall's material, as well as whether there's already a window in the spot where you’re planning to install said bay window. You may need a sledgehammer to knock down any studs found in the wall. If sheathing and siding nails are secured, cut them off using a reciprocating saw. Next, remove the sill that’s in place, as this will help you determine the window's rough opening width.
Then, frame the opening in such a way that it can accommodate the flashing. The window jambs should be fastened directly to the window's framing. Note that your bow window may have flanges. If so, temporarily position the window in the hole. Next, wedge into place using shims and mark the sides to then cut the siding.
Now, cut the siding according to the measurements taken. Make sure that the area where you will be installing the window has a levelled, flat surface. Grab a level to ensure the surface is actually level. If the space is not level, you will have to build a frame on which the window will rest.
Source: Canva
Once you’ve prepared the area, mark the location where the brackets will be secured according to the manufacturer's instructions. Drill a few holes to wedge and level the unit. This can be completed by inserting shims between the top of the frame and the rough opening. Once completed, you can temporarily position the window in the cut-out. You’ll definitely need someone to help out during this process, so rally up friends or loved ones.
However, before temporarily installing the window, cut a couple of temporary supports to fit directly underneath it. This part of the installation process is meant to check whether the unit is level, and lays flat across. Next, drive screws into the holes you’ve made so that the window can be upheld temporarily. Make sure the window's individual panes can open and close as smoothly as possible.
If you haven’t had a roof cap for your bay window manufactured, now is the time to build it. It will be much easier to make adjustments when working at ground level. If you haven’t done so already, make a template for your roof or take down the measurements so that you’re able to make it. During this phase of the process, make sure to drill holes that are big enough for the support cables should you require additional overhead support. Cut out the structure's outline in the sheathing and build the roof.
Once the roof is ready to be installed, position it and mark the spot where you'll cut the siding to allow for flashing. Once secured in place, you’ll want to form a shallow gap to add foam insulation. Make sure to insulate the space between the window frame and the wall. If you’re working with a spray foam sealant, note that it will expand to form an air barrier to keep cold air in and hot air out. Now, your bay window is ready to be finished in any way you’d like, whether that be adding decorative trim or casing.
Bay windows are considered high-end features in terms of window designs. They’re appreciated on account of their ability to provide panoramic views. Furthermore, they automatically make a room feel and look bigger. The only hitch rests in its installation cost and the fact that its installation is restricted to select areas of a home.
A bay or bow window usually costs around $2,500 and $4,000.
Find more information on different window models in our tailored guide.
There are standards relating to windows and other opening types per the Civil Code of Quebec. Indeed, it is illegal to have an unobstructed view, such as a clear-glass window or door, within 1.50 metres from your and your neighbour’s property line.
If you’re planning on installing new doors and windows or altering their size, you should request a work permit. Furthermore, you will have to abide by the regulations regarding natural lighting, ventilation, and security. The latter may not be necessary if your project solely entails replacing or repairing an identically sized window or door.
Inquire with your town hall representatives to fully understand the guidelines to follow before undertaking your renovation project.
Determine the size and shape of the window
Gather tools
Prepare the work area (remove furniture, seal ducts)
Cut out the bay window opening
Insert wedges (shims)
Secure the jambs
Cut the siding
Make sure everything is level
Build the frame (if needed)
Mark the spots where the brackets will be secured
Drill the holes to wedge and level the unit
Temporarily install the window (install temporary supports)
Build the roof
Insulate the gap between the window frame and the wall
Permanently affix the bay window
Carry out the final details
RenoQuotes.com can help you get quotes for a window project. If you submit your project to us, we’ll put you in contact with top-rated contractors. Fill in the form on the homepage (it only takes a few minutes), and you will get estimates from trusted professionals.
Last modified 2024-03-21
Looking for something else?
Related articles
The latest industry news, interviews, technologies, and resources.
Léa Plourde-Archer • 07 Nov 2023
When a house is put up for sale, it is often necessary to complete a few renovation projects, especially if the house has been on the market for a long time and you’ve had several visitors but no serious offers. Even when you only have a small budget, certain specific improvements can make a big difference, increasing the value of the house along the way.
N/A • 21 Mar 2024
Moving forward with a renovation project often brings to mind the idea of building rather than destroying. Of course, construction implies that a demolition must take place before a new structure can be built. However, the sheer amount of debris produced by demolitions has become a growing concern, as construction sites tend to completely neglect the recycling of materials.
N/A • 07 Nov 2023
Are you hoping to install tiles in your kitchen or bathroom? If choosing the tile pattern and size are initial questions on your mind, what about the technique used when laying tiles?
Karine Dutemple • 07 Nov 2023
Do you have lots of energy to spare and are thinking about buying a house to flip it? Take a look at these few examples of flips to find ideas for this large-scale project!
N/A • 07 Nov 2023
At first sight, the bathroom might appear to be a rather dull and boring space, an afterthought to the overall home. However, humans spend a significant amount of time in their bathrooms, and the style and beauty of the individual should be reflected in the floors, ceilings and walls of every room!