U-value for windows

Compensating for this by cranking the thermostat or turning up the AC results in added energy needs and higher bills. Greater energy efficiency calls for a closer examination of the individual building components to see how they can work individually and in relation to each other in more effective ways. U-factor ratings can help in formulating standardized comparisons and objective evaluations. The U-factor generally refers to the energy efficiency of the complete window assembly, which includes the glazing, window frame and spacer.

The spacer is the component of a window frame that separates the glazing panels, and often reduces the U-factor at the glazing edges. The performance rating of the glazing alone, independent of the frame, is known as the center-of-glass U-factor, but use of this rating is less common. For most energy-efficient windows, the U-factor for the entire window assembly is higher than the U-factor at the center of the glass.

While beneficial in cooling-dominated climates, a low U-factor is most important for windows in heating-dominated climates. The following are recommendations for the most effective window U-factors based on the major climate zones in the United States. Get Started. For example, not every glass panel is manufactured to the exact same standards, and what stacks up in a laboratory might not translate into the real world. To comply with building regulations, windows like every other element of your property must meet a certain minimum U-value.

Double-glazed windows, filled with argon, are typically 1. The British Fenestration Rating Council provide a colour-coded rating system to help homeowners distinguish between different qualities of window. Good windows which keep the heat in are rated A or above.

Bad ones are related E or below. Triple-glazed windows are more effective insulators than their double-glazed counterparts. That said, there are a few drawbacks to consider. Putting to one side practical considerations like these, there are a few instances where a triple-glazed window might not be as good a choice as its U-value might suggest. This is because of heat gain, or a lack of it. As such, south-facing windows which receive direct sunlight might be better suited to double-glazing than triple-glazing.

Generally speaking, the lower the U-value, the better. Ready to shop for new windows? You can also get an estimated quote here. Image credit 1 , image credit 2.

Window Energy Ratings provide a simplified method of understanding the energy saving properties of a window. Some window performance figures are expressed with a U-Value and others with a Window Energy Rating, although the latter has been adopted as the more commonly used. In simple terms, the calculation uses a notional figure on the energy balance of a typical UK house in a year using a variety of window styles and configurations.

It is important to understand these are calculations that, in a real-world situation, could be better or worse than the stated performance figures. Glass units today differ substantially from early generation double glazing. If you have old double glazed windows and doors before it is likely these have metal spacer bars around the sealed unit and just air space in between. All these coatings and materials enable a low U Value to a modern window.

To give you an indication of U-Values in the home, we give some approximate figures compared to your property roof, walls and floors. Our double glazed units include a soft-coat low-e coating, argon gas between the glass panes and a warm edge spacer bar. Textured and patterned glass located in bathrooms has the same glass specification with the internal pane having the obscure glass pattern.

Our windows have a whole product U-Value of 1. You can find out more about this brilliantly engineered and highly sustainable timber material here. With an ancient Established in by Jonathan Hey, our journey has been full of exciting and rewarding home transformations up and down the country.