Window panes

Single pane (aka. single glazed) windows are the least expensive to purchase and install, but they provide little in the way of insu­lation or sound blocking. While a single pane window might be okay for use on Vancouver Island, it’s not the ideal choice for cold season climates – practically the rest of Canada. They’re a better choice for garages, sheds and perhaps workshops.

Double pane windows are the most popular choice as they pro­vide much better energy efficiency and sound blocking than single pane. In these windows the two panes of sealed glass are separated by an air space that provides the insulation. These are also referred to as insulating glass or thermal glass.

Triple pane windows have three panes of glass. They’re more energy efficient (saving an estimated 2-3% on your annual heating bill), but cost anywhere from 10-15% more to purchase.

It’s common for both double and triple pane windows to have an inert gas (argon or krypton) injected between the panes – it increases the insulating value of the windows. Both are also avail­able with a low-e (low-emissivity) coating – a microscopic layer of metallic oxide applied to the glass, which reduces the amount of infrared and ultraviolet light infiltration, keeping your home cooler in the summer, while reflecting heat back into your home during the winter.

If you’re looking to add an additional level of security to your home and help reduce ambient noise, some manufacturers offer safety glass, which comes in two formats. Tempered glass, the least expensive, is made of a single pane heated and then quickly cooled to increase its durability. Laminated glass consists of two or more panes of glass fused together by a layer of plastic, and unlike regu­lar or tempered glass, it won’t shatter when broken.

To add a more traditional appearance some manufacturers offer removable grids that you attach over the inside pane. The grids can be removed to facilitate cleaning the panes. Other manufacturers offer both permanent grills and inte­gral blinds that are factory installed between the panes in double-paned windows.

Window styles

There are three main types of win­dows, categorized by how they open – fixed (or picture), sliding (or glid­ing), and tilting (or crank). Skylights are typically fixed, while bow and bay windows can be fixed, sliding, or tilt­ing. Most of these styles come in a wide variety of sizes, and in single, double or triple pane.

Fixed (or picture) windows don’t open, which makes them suitable where you want light, but not ventilation. They’re available with clear, privacy or decorative glass.

Windows that you open vertically are called sliders (or gliders). Those that you open horizontally are single or double hung (or sash) windows.

Tilting (or crank) windows pivot outwards when opened, and come in three types:

• Awning windows pivot on top mounted hinges. A less common ver­sion are those that pivot on a bottom hinge– called Hoppers;
• Casement windows pivot on left- or right-side mounted hinges;
• Single or double hung windows with a tilt feature pivot inward on side pins.

Bay windows usually have a large central window flanked by two narrow windows, while bow windows typically have four to six uni­formly sized windows.

Not all windows are square or rectangular. Many manufacturers can make custom windows in a variety of configurations, includ­ing quarter round, camber-top, triangular, and elliptical. Of course, expect to pay a premium for these atypical shapes.

It’s a good idea to choose windows that have an ‘Energy Star’ label. These are windows that meet government standards for energy efficiency based on specific climate zones across the country.

Window frames

There are five types of materials used to frame window panes – vinyl, fiberglass, aluminum, composite and wood. There are also frames comprised of a wood core sheathed in vinyl, fiberglass or aluminum.

Vinyl: The Affordable Choice
By far the most popular choice in windows as it’s the least expen­sive. Available in a range of colours and options of smooth, textured or faux wood finishes. They can have a hollow core or be filled with foam for extra insulation. Typically last about 30 years.

Cost: $
Pros: Low cost, energy efficient, UV resistant, easy to install, low maintenance, affordable, won’t warp, peel or rot.
Cons: More prone to breakage than other materials. Vinyl contracts and expands with changing temperatures much more than other materials, which reduces its ability to seal. Can warp if exposed to prolonged, intense sunlight. Can’t be repainted.

Aluminum: Provides a Contemporary Look
Can either be extruded (more durable) or roll-formed. Choose win­dows that have a thermal break – an insulating barrier between the inside and outside of the window frame. Last about 30 to 40 years.

Cost: $$
Pros: High strength and structural integrity, light weight, low maintenance, rea­sonably dent resistant, very durable, available in a variety of colours.
Cons: Less insulation value than other materials, prone to condensation, sub­ject to fading in strong sunlight, anodized aluminum can’t be repainted, more difficult for DIYers to install.

Fiberglass: Super Strong and Long Lasting
Made of plastic resins and glass fibers. They can have a hollow core or be filled with foam for extra insulation. Available in a variety of colours and textures to mimic wood. Typically last up to 50 years.

Cost: $$$
Pros: Much stronger than vinyl, lower heat conductivity than aluminum, very energy efficient, low maintenance, resists swelling, rotting and warping, fade resistant, can be repainted.
Cons: Repainted windows may peel or fade, more difficult to repair than vinyl, more difficult for DIYers to install.

Composite: The Eco-friendly Choice
Made from wood fiber and plastic resins to mimic the look of wood. Combines the strength of fiberglass and the performance of real wood. Expect them to last at least 40 years.

Cost: $$ to $$$$
Pros: Very energy efficient, less vulnerable to expansion and contraction than vinyl, fiberglass or wood, can be painted or re-stained, low maintenance, won’t fade, flake, blister, or peel.
Cons: Relatively new on the market with little long-term performance assessment.

Wood: Classic Appeal
For timeless beauty and appeal it’s hard to beat wood. If properly maintained can last the life of your home.

Cost: $$$$
Pros: Superior visual appeal, durable and long lasting if well maintained, very energy efficient, inside frame can be painted or stained to match interior décor, matching casings usually available.
Cons: Needs more maintenance than other materials, potential for rot, mold or mildew if not properly maintained, higher cost than other types.

Wood Clad: The Compromise Choice
Sheathed in vinyl, fiberglass, or aluminum. Requires a waterproof rubber membrane around the cladding and a sill pan. Expect them to last around 40 years.

Cost: $$$$$
Pros: The clad exterior protects the wood core from the elements and reduces maintenance. The interior wood frame can be stained or painted and may be available in various wood species such as pine, fir, maple and oak.
Cons: More vulnerable to expansion and contraction than solid vinyl, fiberglass or aluminum, more difficult for DIYers to install.

Definitions

Here are some additional terms that relate to windows.

R-Value – Measures a window’s ability to prevent heat transfer. Energy Star windows have a minimum value of 3. The higher the value the better the window is at reducing heat loss.
U-Value (or U-Factor) – Measures how much heat flows through a material. The lower the value, the better the window insulates. Look for values of around 0.4 or less.
Solar Gain (or Solar Heat Gain Coefficient) – An indicator of how much solar radiation the window will admit into a room. The lower the value, the better the window is at blocking heat.
Wind resistance – A measurement of air leakage (in cubic feet per minute typically at 21.1°C and -17.8°C. The lower the per­centage, the better the seal.