There are several builders and companies that specialize in building homes and structures that are designed to block or reduce exposure to electromagnetic waves. Here are a few examples:

• Greenleaf Construction (USA) : They offer EMF-shielding services for new construction and retrofitting existing homes. They use a combination of special construction materials, such as metal-coated window films, metal-coated fabrics, and metal-coated drywall, as well as low-emitting electrical and electronic equipment to reduce exposure to electromagnetic fields.

• Shielded Havens (UK) : They specialize in building and retrofitting homes to reduce exposure to electromagnetic fields. They use a variety of techniques, including the use of special construction materials, such as metal-coated window films, metal-coated fabrics, and metal-coated drywall, as well as low-emitting electrical and electronic equipment to reduce exposure to electromagnetic fields.

• Shielded Living (Australia) : They specialize in building and retrofitting EMF-safe homes. They use a variety of techniques, including the use of special construction materials, such as metal-coated window films, metal-coated fabrics, and metal-coated drywall, as well as low-emitting electrical and electronic equipment to reduce exposure to electromagnetic fields.

It's important to note that these are just a few examples of builders and companies that specialize in building EMF-safe homes, and there are likely many more available in different locations around the world.

It's also important to note that even though these companies offer EMF-shielding services, it's important to consult with experts in the field to determine the most appropriate approach to shielding a building from electromagnetic fields and to visit and inspect the building in person before making a decision.