The primary downside of radiant barriers is their limited effectiveness in cold climates. They are designed to reflect radiant heat, making them less beneficial in cooler conditions where heat retention is more important. 

Radiant barriers require proper installation to maximize effectiveness. Incorrect placement can lead to minimal benefits. They also do not provide insulation, meaning they should be used in conjunction with traditional insulation for optimal energy efficiency. 

Depending on where you live and the conditions of your basement, you may not need to insulate your basement. Your best bet is to talk to a basement remodeling company to find out what they recommend doing.

Insulating your basement can help improve your home's energy efficiency, but it will also increase the cost of your basement remodel project. The average cost of installing basement insulation is $2,400.

Yes, insulating ductwork in a crawl space is a worthwhile investment, especially if you live in a colder climate or run your air conditioning for most of the year. Uninsulated ducts can lose up to 30% of their heating and cooling efficiency, which can significantly impact your electricity bill. The project is a relatively small investment and typically only takes a few hours. It's a particularly simple add-on if you are already hiring someone to insulate the entire crawl space. An added benefit is that insulated ducts put off less hot or cold air, making them less attractive to pests.

It is usually possible to install insulation yourself, but it’s often better to hire an insulation professional. An experienced insulation pro can determine which type of insulation is best for your space and the R-value get the most value and comfort in your home. Certain types of insulation can cause skin, eye, and lung irritation, and a professional will have the equipment necessary to keep themselves safe and limit the effect on your indoor air quality after the installation. Certain types of insulation—like blown-in and loose-fill insulation—demand a professional for proper functionality and safe installation.