Above-ground shelters are typically steel safe rooms anchored to an existing concrete slab in a garage or interior space. Because they avoid excavation entirely, they sidestep South Florida’s high water table and the drainage work that underground installs require. The trade-off is visibility: an above-ground unit occupies floor space in the garage or a room. For slab-on-grade homes common across Palm Beach, this is often the most straightforward path to an ICC 500-compliant shelter without major structural disruption.
Underground shelters are set below grade in the backyard and are preferred when a concealed or yard-based setup fits the property better. In South Florida, the water table and soil conditions make waterproofing and drainage a primary design concern, not an afterthought. The site assessment covers excavation depth, backfill method, waterproofing membrane, and floor drain placement so that water intrusion risk is addressed in the engineering-certified design before any digging starts.
Safe room conversions reinforce an existing interior room or basement to meet FEMA P-320 safe room standards without building a separate structure. The contractor inspects the existing space for structural suitability, then specifies concrete block or steel-framed wall reinforcement, an impact-rated door, anchor bolt placement, and a moisture barrier. This option suits homeowners who want to use existing square footage rather than add a new structure, provided the room can support the door, wall, and anchoring requirements the design calls for.