What type of insulation is commonly used in walls?

Insulation plays a crucial role in maintaining energy efficiency and comfort in buildings, and several types of insulation are commonly used in walls, each with its advantages. Fiberglass batts are among the most widely recognized and utilized forms of insulation, known for their affordability and effectiveness in standard wall cavities. Cellulose, made from recycled paper products, is an eco-friendly option that is often used in wall insulation, providing good thermal resistance and soundproofing capabilities. Spray foam insulation is valued for its superior air-sealing properties and ability to expand and fill gaps in hard-to-reach areas, making it an excellent choice for irregular wall spaces.

The correct answer encompasses all mentioned types of insulation, reflecting the variety available for different building needs and preferences. Each of these options offers distinct benefits that can be leveraged based on the specific requirements of insulation in walls, thereby providing a comprehensive approach to thermal management in construction.