In-ground pools take 8-12 weeks to install, with fiberglass fastest (3-6 weeks) and concrete slowest (12+ weeks). Fiberglass offers low maintenance but limited designs (40K−85K), concrete is fully customizable but costly (50K−100K+), while vinyl is affordable (35K−65K) but needs liner replacements. Local laws usually mandate 4-ft fencing, self-latching gates, and permits. Add safety features like pool covers, non-slip decking, and shallow zones for kids. Always check zoning rules for setback requirements before breaking ground.