U Values For Doors And Windows

Typical u values on windows and window energy ratings are similar to the familiar energy labels you see on home appliances rated from a the lowest up to g the highest or worst performing.

U values for doors and windows.

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. Window energy ratings provide a simplified method of understanding the energy saving properties of a window. Our u value calculator is a whole window calculator designed to calculate an accurate u value of windows and doors. A higher u factor allows heat to escape.

This is desirable in very hot and sunny locations to avoid the greenhouse effect inside a home. Typically double glazed windows record a u value of between 1 2 w m k and 3 7 w m k while triple glazed windows are usually rated below 1 w m k. The lower the u factor the better the window is at keeping heat inside this is desirable in colder climates like the northeast. A u value calculated by us should be sufficient to satisfy the requirements of building regulations.

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 4 w m2k while thicker triple glazed windows can go as low as 0 7 w m2k. We can advise on how you might achieve the required standard. According to part l1a of current building regulations a domestic window installation should achieve a u value no higher than 1 4 w m k.

U factor u value range between 20 to 1 20. This calculated value conforms with bs en iso 10077 part 1. U value is an inverse measure. Thus a single paned window with a basic aluminum frame has a u value above 1 usually around 1 25 while triple pane windows may have u values around 25 or lower.

How is u value determined. Improved education and awareness of the cost of heating and cooling that escapes from poorly insulated components and glass panes have led to window and door manufacturers developing energy efficient windows and doors typically labeled r5 u 2 meaning the glass is the most energy efficient possible at a 5 rating and the window or door with all of it s built out components are a 2 which is almost as low as any rating can go remember a 5 is the highest energy rating for r value which is. High performance double pane windows can have u factors of 0 30 or lower while some triple pane windows can achieve u factors as low as 0 15.