When sourcing prefab concrete houses, you must prioritize structural integrity and material composition. Ensure the concrete grade is at least C30/37 for load-bearing walls to guarantee durability. The steel reinforcement (rebar) should be hot-dip galvanized to prevent corrosion, especially in humid climates. Additionally, verify the thermal insulation layer (typically EPS, XPS, or Rockwool); for energy efficiency, the U-value should align with your local building codes (e.g., <0.30 W/m²K for cold regions).