The material around a window is simply called the window frame, but the individual pieces also have different names. The top portion of the frame is called the head, the side pieces are called jambs, and the bottom portion is called the sill. If you have multiple windows next to each other, you’ll also have a mullion, which is the frame piece that separates the individual windows. Windows stacked on top of each other are separated by a horizontal frame piece, which is called a transom.

On average, bay windows are three times as expensive as a standard double-hung window, so up-front cost is a major drawback. They also let in more natural light than most other types of windows, which can be a positive thing, but it can also lead to more aggressive fading and UV damage to furniture and flooring. Larger windows allow for more heat transfer, so bay windows tend to be less energy-efficient due to their size. Finally, window treatments for bay windows can be more challenging to find, and they’re more expensive than those you’d place over standard-sized windows.

Sometimes, you can buy windows directly from the manufacturer, and it may be cheaper than buying through a third party or wholesaler. Manufacturers may also offer more options, including custom shapes and features, or better warranties if you purchase through them directly. 

However, some companies limit the ability to buy from them, especially if you need standard pre-fabricated sizes, so don’t expect this service from every manufacturer.

The cost of window replacement is about $290 per window on average, with a typical price range of $180 to $410. However, costs can be as low as $100 or as high as $780 or more. The total price depends on several factors, including the size, type, brand, and number of windows being replaced. The frame material and glass type also significantly impact the cost.

• Frame Material Costs (per window):

• Aluminum: $275

• Vinyl: $550

• Wood: $800

• Composite: $900

• Fiberglass: $1,250

• Glass Type: Simple double-glazed windows are cheaper ($3 to $6 per sq. ft.) than stronger tempered glass ($12 to $14 per sq. ft.).