Picture windows live up to their name–they provide a stunning view of the outdoors while remaining stationary, unlike traditional windows, which open and slide open and closed. Find the best passive house window.
Window frames may range from simple, non-operable versions to complex, operable ones with many moving parts and adjustable mechanisms. For operable windows, frame materials may include wood, uPVC, or aluminum.
Frame Material
Your window frame materials play an integral part in their functionality, durability, and energy efficiency. Wood, fiberglass, vinyl, and aluminum are among your many options. Picking one will depend on aesthetic preferences, budgetary constraints, climate considerations, and maintenance preferences.
Wood frames provide a classic aesthetic for your home and can be stained or painted to suit your taste. They help keep heating and cooling bills down while insulating well. Unfortunately, however, they’re susceptible to rot in certain climates, so they are not recommended in others. Aluminum frames are lightweight yet sturdy but conduct heat quickly, so they require insulation with a thermal break in order to be used effectively; additionally, they’re subject to contraction/expansion, which leads to seal deterioration/leaks over time.
Vinyl window frames offer an affordable, modern alternative to aluminum and wood window frames. They feature good moisture resistance and relatively minimal maintenance requirements. Their hollow cavities can also be filled with insulation, which dramatically enhances their thermal performance compared with uninsulated wood or aluminum options. However, over time, vinyl may fade and become yellow, resulting in color fading and yellowing effects.
Fiberglass may be more costly than other frame materials, but it offers many advantages over them. Engineered for strength, it can mimic the appearance of wood without swelling, warping, or warping over time; plus, it insulates well and can withstand significant climate shifts without warping or warping.
UPVC (unplasticized polyvinyl chloride) is another excellent newer option that stands up well against UV rays. It offers more color options and profiles tailored specifically for window openings than vinyl. Plus, it is more resistant to fading and yellowing!
Sill
Window sills are horizontal surfaces lining the bottom of windows or door openings that support windows or doors. They are made of materials like wood, concrete, stone, or metal and supported by a lintel. A lintel transfers loads from above onto other parts of a building structure by transferring loads away from walls onto other portions.
A sill is also essential in protecting against rain and snow by keeping moisture from seeping into the gap between the wall and window frame. In addition to their practical uses, sills also provide aesthetic elements in any home—for instance, they may feature tiles or wrought iron grilles to add visual interest and elegance, while weep holes allow water to escape through them, preventing damage to the window, frame, or home structure.
The material choice of window frames has an enormous effect on their thermal characteristics, accounting for 10-30% of total window units. Wood, fiberglass, and extruded rigid PVC frames are popular choices. Wood offers warmth and aesthetics as well as insulation properties; however, it needs regular sealing/staining maintenance to stay durable and prevent moisture damage.
Vinyl and aluminum windows offer an effective alternative to wooden frames by protecting their exterior while decreasing maintenance requirements. Many manufacturers provide different finishes and colors of these types of windows to fit with the style and decor of any home, and low-E glass can further increase energy efficiency.
Header
A header is a structural member that spans the gap between window openings and building walls, serving to transfer loads from above the window opening to the sill and foundation below. Headers also play an essential role in improving window thermal performance; their U-factor rating (NFRC label rating) is strongly determined by frame and glazing elements.
Builders typically construct wood frames for non-bearing walls using wood clad with vinyl or aluminum siding to protect them from moisture and decay, though these materials have limited insulating capabilities. One effective way of improving their insulation performance is using advanced framing details that reduce thermal bridging while saving space for insulation.
While standard headers consist of double 2x12s, many framing professionals and do-it-yourselfers employ smaller lumber like two-by-fours when building headers for more giant window openings, unfortunately, smaller lumber increases thermal bridging between outside and inside surfaces of a header, potentially decreasing its insulating value and rendering less effective insulation value.
Lamellar veneer lumber (LVL) or glulam beams may be better options when creating window headers than sawn lumber. They are made up of multiple thin veneer layers bonded together under pressure to form large beams that are lighter than their sawn counterparts and offer improved durability.
Each window header requires both king studs and jack studs for support, with the former being attached at either end to prevent warping of the header from heavy loads and prevent warping altogether. More extended window headers or those bearing greater loads require trimmers that rest under each side and are nailed into their king studs alongside them as needed for additional load support.
Jamb
Window frames support windows and provide insulation against air and water entering your home. They also house the sash that allows windows to open up, down, or side-to-side. Their structure can range from very simple with no moving parts to complex with numerous moving parts and an array of features in operable window models.
A window frame comprises three primary components: the sill, head, and jambs. The sill sits at the bottom of window openings and is typically constructed of wood or fiberglass. It may come equipped with a baseboard to cover gaps between itself and floor surfaces. Jambs provide vertical support to hold up sashes.
There are various kinds of jambs, from standard and extension models to wrap-around pieces. Additionally, casings and trim pieces can also be added for decorative purposes to the frame. In fact, some trim pieces even help with insulation by sealing gaps between window frames and walls.
Window frames serve two critical purposes for any home: protecting it from moisture, air, and insects entering, as well as increasing energy efficiency by limiting heat transfer through glass and frames. When shopping for new windows, it’s essential to pay attention to the thermal characteristics of frames – such as an NFRC label displaying its U-factor rating; higher U-factor ratings indicate less efficient models.
Casing
Casings are used around windows as decorative trim. Their appearance can range from basic to ornate. Wood is often the material of choice, though some companies have developed composites comprised of wood and polymers for window casing that offer excellent stability, moisture resistance, and decay protection – they even stain or paint like regular wood! Furthermore, composite casings often cost less than their counterparts while providing an opportunity to reuse significant quantities of scrap wood that would otherwise be wasted.
Windows are either fixed or operable; fixed ones cannot be moved, while operable ones can be opened and closed to let in fresh air.
Most modern windows feature multiple panes of glass arranged either side-by-side or one atop another within their frame, commonly referred to as an IGU (insulated glazing unit). IGUs contain spacers and inert gas between their panels in order to lower energy costs while improving home comfort.
Other features of windows may include a lift handle for raising the lower part of single or double-hung windows; sash locks mounted either to a check rail or vertical stile to prevent involuntary closure and rattling; tilt latches on casement/awning windows that enable homeowners to control how far out their sashes extend for cleaning; balances which counterbalance weight for smooth operation, weatherstripping to seal gaps between frame and jamb in order to minimize air leakage, weatherstripping to seal gaps between frames/jambs in order to minimize air leakage;
