If you have enough in your home-improvement budget to purchase new, more efficient windows, doors or appliances, you face a new challenge. Products -- even those touted as energy efficient -- vary widely in the amount of efficiency they provide over traditional products.
Thankfully, a number of resources can help you make sense of this sea of products. Most efficiency-boosting items, such as windows, insulation and even appliances, have ratings that can give you a sense of how much or how little energy they consume. Insulation products, for example, are measured by their R-value; the higher a product's R-value, the less heat it will transfer [source: U.S. Department of Energy]. Conversely, windows are rated by measurements of U-factor and Solar Heat Gain Coefficient (SHGC); the lower these numbers, the more efficient the windows [source: Putnam].
Water heaters, air conditioners and dishwashers all have their own efficiency measurements. Read up on what these measurements and values mean before you start shopping, and you'll be well prepared to strike a balance between the energy you wish to save and the budget that controls the extent of the home improvements you can make.