New Construction Windows for Toronto Homes: A Buyer's Guide

New construction windows are designed to be installed while a home or building is being constructed, before the surrounding exterior finishes are completed. While replacement windows are made to fit into an existing window opening, new construction windows are usually attached directly to the wall framing and integrated into the building envelope.

If you want to install new windows or replace the existing ones, it will help you to understand what new construction windows are exactly, when they're a good option, and when replacement windows are better.

What Are New Construction Windows?

New construction windows are window units designed to be installed in a new or exposed wall opening. They are installed before siding, brick, stucco, or other exterior finishes are completed.

Most new construction windows have a nailing fin, also known as an installation flange. The flange extends around the outside of the window and provides a surface for fastening the unit directly to the surrounding framing.

Because the wall is accessible during construction, the window can be integrated with the surrounding flashing, weather-resistant barrier, insulation, and air-sealing components to help minimize air and water leaks. Moreover, new construction windows can maximize the amount of natural light because they utilize the full rough openings.

New construction windows are thus commonly used for:

• New builds
• Home additions
• New commercial or multi-unit buildings
• Major renovations where the wall framing is exposed
• Projects involving a newly created or substantially modified window opening.

New Construction Windows vs Replacement Windows

The main difference between new construction windows and replacement windows is how they are installed. Here's what you need to know:

In other words, with new construction windows, the installer has access to the framing. With a replacement window, the goal is to replace the existing unit while disturbing as little of the surrounding wall and exterior finish as possible.

Neither installation method is automatically better for every project. To determine which is the best for your specific renovation project, assess the condition of the existing opening and the scope of the construction work.

When Do Windows Get Installed in New Construction?

Windows are typically installed after the wall framing and rough openings are completed, but before the exterior finishes such as siding, brick, or stucco are installed. This allows the windows to be properly integrated with the building's flashing, weather-resistant barrier, insulation, and air-sealing systems.

The exact timing can vary by the construction method and project schedule, but the general sequence is:

• Wall framing → rough openings → window installation → flashing/weatherproofing → exterior cladding → interior finishing

Installing the windows at this stage allows the contractor to verify that the units fit the rough openings correctly and that the window-to-wall connection is properly sealed before the wall is closed up.

New Construction Windows vs Other Replacement Methods

New construction window replacement is often called full-frame replacement, while replacement window projects are often called retrofit projects. While this is broadly correct, these terms are not literal synonyms. Technically:

• New construction window = a type of window/product designed for installation in new or exposed framing
• Full-frame replacement = an installation approach where the existing window and frame are removed, which may disturb interior casing
• Replacement window = the broader product category for replacing an existing window
• Retrofit/insert = a replacement installation that keeps the existing frame

New Construction Window Components

The installation of a new construction window starts with preparing the rough opening in the wall framing. The rough opening is larger than the finished window unit and provides the space needed to position, secure, insulate, and seal the window according to the manufacturer's requirements.

The process generally involves several components:

• Rough opening: The framed opening prepared to receive the window.
• Nailing fin: The flange around many new construction windows used to fasten the unit to the framing.
• Flashing: Materials installed around the opening to direct water away from the window and the wall.
• Weather-resistant barrier: The surrounding building-envelope layer that helps protect the wall from water intrusion.
• Air sealing and insulation: Materials used around the window perimeter to reduce unwanted air movement and heat transfer.
• Exterior finish: Siding, brick, cladding, or another exterior material that is completed around the installed window.

Because all of these components can be coordinated while the wall is being built, new construction window installation forms part of the overall building-envelope process.

What Is the Rough Opening for a New Construction Window?

The rough opening is the framed space in the wall that accommodates the new construction window.

The rough opening doesn't have the same dimensions as the window itself. The opening needs to provide the clearance required for positioning, leveling, fastening, sealing, and other installation requirements specified by the manufacturer.

Getting the rough opening right is especially important in new construction because the framing is being completed before the window is installed.

If the opening is too small, for example, it may not accommodate the window properly. If the opening is incorrectly sized or poorly prepared, it can also make it more difficult to position and seal the unit.

For that reason, rough-opening dimensions should be coordinated with the window manufacturer's specifications before framing is finalized.

What Is a Nailing Fin on a New Construction Window?

A nailing fin is a flange that extends from the exterior perimeter of many new construction window frames. It provides a surface for fastening the window to the surrounding wall framing.

The nailing fin also plays a role in integrating the window with the flashing and weather-management system.

Because the fin extends beyond the frame, the window can be installed before the exterior cladding is completed. The surrounding wall materials can then be layered and sealed around the window as part of the construction process.

Not every new construction window uses the same fastening or flange design, though, so installation should always follow the manufacturer's requirements.

When Are New Construction Windows Used?

New Home Construction

New construction windows are often used when building a new home because the framing and rough openings can be designed around the selected window units.

New construction windows offer architectural flexibility to change the size or shape of openings. This gives the builder the opportunity to coordinate window dimensions, framing, flashing, insulation, and exterior finishes from the beginning of the project.

Home Additions

A new addition creates new exterior walls and window openings, making it similar to new construction from an installation perspective. New construction windows can be installed while the addition's framing is exposed and then incorporated into the completed wall assembly.

Major Renovations

New construction windows can also be used during a major renovation when the existing wall is opened up or rebuilt.

For example, a project may require new construction windows when:

• The wall framing is exposed
• An existing rough opening is being significantly changed
• A window is being moved or enlarged
• Exterior finishes are being removed as part of the renovation
• Part of the wall assembly is being reconstructed

How Are New Construction Windows Installed?

The exact installation process for new construction windows depends on the product and on the building-envelope design. However, a typical new construction window installation includes the following steps.

1. Preparing the Rough Opening

The opening is framed to the dimensions required for the window. The surrounding framing is inspected to make sure the opening is suitable for installation.

2. Preparing the Opening for Water Management

Sill flashing and other required water-management components are installed according to the window manufacturer's instructions and the building-envelope design.

3. Positioning and Securing the Window

The window is then placed into the rough opening and positioned correctly.

Then, the window is fastened to the surrounding framing using a specific fastening method, which commonly involves the nailing fin or installation flange.

4. Checking Alignment

The installer checks that the window is level, plumb, square, and properly positioned. Operable sections should also be tested to make sure they open, close, and lock correctly.

5. Sealing the Window for Rain Protection

At this point, the installers overlap materials so water naturally flows down and away from the house.

Special waterproof tape is stuck over the sides of the window to cover any gaps. Then, a small metal or plastic shield is placed over the top of the window to deflect rain. The house's outer weatherproofing wrap is taped down over everything, which ensures that any water running down the wall stays on the outside and cannot leak into your home.

6. Air-Sealing and Insulation

The perimeter of the window is sealed and insulated as required by the installation system. This helps reduce unwanted air movement and provides a transition between the window and the surrounding wall assembly.

7. Completing the Exterior and Interior

Once the window has been correctly installed and sealed, the surrounding siding, brick, trim, drywall, or other finishes can be completed.

Proper installation matters as much as the window itself. A high-performance window can still have problems with air or water infiltration if the opening, flashing, fastening, or perimeter sealing is not handled correctly.

Can You Use New Construction Windows in an Existing House?

Yes, you can sometimes use new construction windows in an existing house, but it depends on the scope of the project.

New construction windows can be installed in an existing home when the surrounding wall is being opened up enough to expose the framing or when the existing window opening is being substantially reconstructed.

New construction windows may be a good option during a renovation that involves:

• Removing exterior cladding
• Rebuilding part of an exterior wall
• Changing the size of a window opening
• Relocating a window
• Constructing a new addition

For a standard window replacement where the existing frame and surrounding wall remain in place, a replacement window is generally designed to be installed without reconstructing the entire opening.

The important question is therefore not whether a new construction window can be installed in an existing opening, but whether the project provides the access and wall conditions required by this installation method.

Are New Construction Windows Energy-Efficient?

New construction windows can be highly energy-efficient, but they are not automatically energy-efficient. The energy performance of a window, whether it's a new construction window or a replacement window, depends on factors like:

• Glazing configuration
• Frame construction
• Energy ratings like U-factor and solar heat gain coefficient
• Air leakage
• Installation quality

The advantage of installing windows during new construction is that they can be incorporated into the wall assembly from the beginning, which can help provide better insulation.

How Much Do New Construction Windows Cost?

New construction windows are generally more expensive than replacement windows because their installation is more complex. That said, the final price depends on multiple factors, including:

When assessing the window's cost, it's important to consider its long-term value as well. For example, better energy ratings or ENERGY STAR-certified windows (which may increase the window's price) can reduce heat loss and heat gain and lead to lower heating and cooling costs. Likewise, windows with Low-E coatings may be more expensive, but they help reflect heat during winter and block solar heat during summer.

Frame Materials for New Construction Windows

New construction windows are available with different frame materials. The choice can affect the window's thermal performance, appearance, durability, maintenance, and cost. The most common options include vinyl, aluminum, fiberglass, wood, and composite materials.

Vinyl Windows

Vinyl windows are a common choice for new residential construction because they require relatively little maintenance and can provide good thermal insulation. Vinyl frames are available in a range of window styles and configurations, and come in multiple color variants to enhance home interior and exterior aesthetics.

Vinyl frames can work well for projects where energy performance and ease of maintenance are priorities.

Aluminum Windows

Aluminum windows offer a strong, durable frame that can support large window configurations and relatively narrow sightlines, being suitable for modern design customizations. Aluminum may also be a better choice for larger triple-pane glass configurations, which are heavier.

That said, aluminum is highly conductive, so the thermal design of the frame is particularly important when selecting aluminum new construction windows.

Fiberglass Windows

Fiberglass is a durable window frame material with good dimensional stability. It is less susceptible to expansion and contraction than other materials and can be a suitable option for new construction projects where long-term durability and thermal performance are important.

Wood Windows

Wood provides a traditional, natural appearance and can complement a range of architectural and window styles. Wood also offers good insulating properties, although it generally requires more maintenance than vinyl or some other frame materials.

Composite Materials

Composite materials, such as Magic's Hybrid Fusion Frame, combine the benefits of several frame materials for enhanced durability, strength, and energy efficiency. The Hybrid Fusion Frame, for example, combines aluminum, steel, and vinyl to provide Toronto homeowners with a strong yet thin frame for unobstructed views, long-term performance, and unmatched strength, being suitable even for large triple-pane windows.

Looking for New Construction Windows?

If you think new construction windows are the best choice for your home renovation project, book a free consultation with Magic and let one of our experts handle everything window-related, from A to Z.

We will assess your home's window rough openings and provide you with a solution that is 100% tailored to your home's design and needs, as well as your preferences and budget. With Magic, you can also bundle window installation with entry door installation.

If you're looking for replacement windows, Magic can also be of help - one of our experts will assess the condition of the old windows and offer a personalized solution that matches your home's architectural style, your region's climate, and your preferences.

FAQs

What is the difference between new construction and replacement windows?

New construction windows are installed into a rough opening and attached to the wall framing, while replacement windows are designed to fit into an existing window opening. New construction installation usually occurs before exterior finishes are completed.

Do new construction windows have nailing fins?

Many new construction windows have nailing fins or installation flanges around the perimeter of the frame. They provide a fastening surface and help integrate the window with the surrounding flash and wall assembly.

Can new construction windows be installed before siding?

Yes, new construction windows are usually installed before the final exterior cladding is completed. This allows contractors to integrate the window and its flashing into the wall assembly before siding or exterior finishes are installed.

Do new construction windows need flashing?

A properly installed new construction window requires an appropriate flashing and water-management system. The specific materials and installation sequences depend on the window manufacturer's instructions and the building-envelope design.

Can new construction windows be used for a home addition?

Yes, new construction windows can be used for a home addition because the walls and window openings are framed as part of the new construction. The windows can therefore be installed before the addition's exterior finishes are completed.

Are new construction windows more energy-efficient than replacement windows?

New construction windows are not automatically more energy-efficient than replacement windows, but they may provide better insulation, regardless of the unit's energy performance metrics, because they offer a robust, integrated weather seal when properly installed. For example, new double-pane construction windows may not be more energy-efficient than replacement triple-pane windows, even though they have a more robust weather seal.

How long does it take to install new construction windows?

Installing new construction windows often takes more time than installing replacement windows. The final installation time depends on the number and size of windows, the condition of the rough openings, the building-envelope requirements, and the complexity of the project.