Boxabl 2-Bedroom Casita: Foundation Plans & Requirements
Model BXB-000016 — two 19'x19' modules, 13,000 lbs, rated for 140 mph wind and Seismic Design Category D.
Key Specs for Foundation Design
Square Footage
722 sq ft
Footprint
2 x 19' x 19'
Configuration
2 Bed / 1 Bath
Weight
13,000 lbs total across two modules
What the 2-Bed Casita Foundation Must Do
At 13,000 lbs across two modules, dead load is still modest — wind uplift and seismic anchorage, not gravity, usually govern the foundation design.
Factory ratings: 40 psf floor live load, 20 psf roof live load (up to 100 psf ground snow with truss roof), 140/120 mph wind (Exp B/C), Seismic Design Category D.
The multi-module connection requires foundation layout tolerances tighter than typical site-built work — our plans dimension both module bearing lines and anchor locations explicitly.
In hurricane and high-seismic regions, hold-down hardware and shear transfer detailing are the items plan reviewers check line by line.
Approval status: Follows the Casita line's state pathways. High-wind coastal jurisdictions will review anchorage against the 140/120 mph factory rating.
Foundation Options & Typical Costs
National planning ranges — your state's frost depth, wind, seismic, and soils pick the winner. Find your state on our state-by-state guides.
Concrete Slab
from $6,000A single layer of concrete, several inches thick. Simple and cost-effective.
Best for: Flat terrain, warm climates, budget-conscious projects
Crawlspace
from $12,000Elevates the home 18-36 inches, providing access to plumbing and electrical systems.
Best for: Sloped lots, areas with moisture concerns, easy maintenance access
Pier & Beam
from $5,000Concrete piers supporting beams and joists. Ideal for challenging terrain.
Best for: Sloped lots, rocky soil, environmentally sensitive areas
Full Basement
from $25,000A full-height underground level, offering additional living or storage space.
Best for: Cold climates, need for extra space, areas with deep frost lines
2-Bed Casita FAQs
What foundation does the Boxabl 2-Bedroom need?
A permanent foundation engineered for both modules — slab-on-grade, stem wall/crawlspace, or engineered piers — with anchorage designed for the unit's 140/120 mph wind rating and SDC D seismic rating. PE-stamped plans are required for permits in virtually every jurisdiction.
How much does a 2-Bed Casita foundation cost?
Slab foundations typically run $15,000–$25,000 for the double-module footprint depending on region; engineering plans from $749. See our full 2-Bed cost guide in Resources.
Is the 2-Bed Casita suitable for hurricane zones?
The factory rating is 140/120 mph (Exposure B/C), which covers much of the hurricane coast — but your foundation anchorage must be engineered to match, and coastal counties (Florida HVHZ, Texas TDI windstorm) have additional requirements. That site-specific engineering is exactly what we do.
We provide foundation engineering only — Boxabl units are sold separately by Boxabl Inc. Specs above reflect Boxabl's published documentation and may change; always confirm current specs with the manufacturer.