Castleblock, Inc.

Castleblock is a Hawaiʻi and California–based prefab and modular home supplier with more than thirty years of experience in new building technologies. Our family has been in Southern California for over one hundred years and in Hawaiʻi for thirty years.

We concentrate on durable, factory-built, heavy steel-based housing systems designed to reduce onsite build time and improve performance against common climate risks—rated for 160 mph winds, with galvanized, powder-coated finishes, termite resistance, and efficient heating and cooling. Units carry a one-hour fire rating. Minimal skills and tools are required for set up. Each package includes a three-year warranty, full installation manual, and support videos. Our product emphasizes a 50+ year lifespan, durability, low maintenance, fast installation (often within days), and cost savings at roughly one-third the cost of conventional construction.

The “Flip Classic B” is our most popular model, well suited as an ADU or standalone home. We also offer studio (one-bedroom) and three-bedroom designs, which can be combined to meet varying needs. The Classic B is a 430 sq ft, two-bedroom, one-bath layout with a full kitchen package including cabinetry, sink, faucet, countertops, and range hood. It is delivered as a factory-finished unit for rapid onsite assembly.

Options include carports, covered verandas, and bedroom cabinetry. The unit weighs approximately 13,000 lbs. That is heavy duty. Standard features include dual-glazed, low-E anodized aluminum windows with screens and integrated blinds, plus full insulation in floors, roof, and walls. Plumbing is pre-configured for an exterior on-demand water heater (not included).

We do not use drywall. Interior walls feature a smooth, washable white surface with a bamboo substrate and no particle board. The result is a ready-to-use home or rental solution designed for fast setup, affordability, and comfortable everyday living. Units can be refolded and relocated as needed. Our factory supplied 5,000 rental units for the 2022 World Cup in Qatar—21st century housing technology at its best. Thank you for considering us.