Insulating a detached garage won't reduce your home's heating or cooling bills—and insulating an attached garage will only have a small effect on your home's energy efficiency. However, insulating an attached garage can reduce the transfer of heating and cooling to and from the outdoors, which can reduce the amount of energy your home needs to stay comfortable. Also, having an insulated garage is just more pleasant. Balance the cost of insulating your garage with how you'll use the space to determine if the project is worth it.

Yes, insulating hot water pipes helps your system run more efficiently. This is especially true in basements in colder climates, where cold air likes to settle in. There are a few ways to insulate water pipes (foam is common) to keep hot water hot, reducing the need for your water heater to constantly heat the water in the tank or your circulator to kick on more than necessary.

Spray foam insulation can last between 80 and 100 years, depending on the type. Closed-cell spray foam is more durable, while open-cell foam is more susceptible to moisture damage and deterioration. It's important to consult a professional installer to understand which type of foam will be used and its specific longevity. Additionally, be aware that some spray foams can damage plastic piping, so if you have PVC or CPVC pipes, discuss this with your installer.

For a DIY solution to protect an outdoor faucet from freezing, you can craft a cover using spare rags, a durable plastic bag, and duct tape. However, be aware that this method may not be as effective as a store-bought cover. Fabric like rags or old towels can absorb water, which could freeze and cause problems. While a DIY cover can work as a temporary stopgap, a proper outdoor faucet cover is inexpensive (often $5 or less), easy to install, and readily available, making it the recommended long-term solution.