Installing sheets of plywood over attic insulation is a popular choice, especially in storage spaces. That said, insulation works by trapping hot air—so it needs extra space to expand and be effective, or you might reduce the energy efficiency of your home. 

It’s important that you never compress the insulation by installing flooring directly on top of it. In many houses, you’ll need to install a subfloor before putting plywood over insulation in your attic.

Cellular shades, also known as honeycomb shades, are the most energy-efficient and insulating window treatments. Their honeycomb structure is made of soft fabric that forms layered cell pockets. These pockets trap air, creating a thermal barrier that reduces heat loss in the winter and blocks heat gain in the summer. For even greater insulation, consider double- or triple-cell varieties. Side-tracked cellular shades, which seal the edges of the window frame, can further minimize air leaks and maximize energy efficiency.

While not every wall requires a vapor barrier, if you do need one and don’t install it, moisture can get between the walls of your home. This can lead to water damage from mold growth or rot, and the excess moisture could also attract pests, including termites, cockroaches, or ants.

The most affordable way to insulate a garage involves choosing cost-effective materials like fiberglass, which comes in batts or rolls and is relatively easy to install. You can often install this type of insulation without needing to add drywall, which helps reduce costs. While a DIY approach might seem cheapest, hiring a professional installer can be highly cost-effective. Experts can accurately determine your garage's specific insulation needs and ensure the best results for your investment, often using batt insulation for the bulk of the project.