Official Engineering & Sourcing Dossier

Complete Factory Engineering Specifications

Comprehensive technical blueprint, structural chassis ratings, foundation engineering, rough-in schematics, and customer service response playbooks for the JJM 20ft Expandable Container House.

1. Architectural & Physical Dimensions

Commercial Model NameJJM 20ft Expandable Container House
Turnkey Base Price$22,000 USD (Turnkey Base including bath, kitchen, electrical, plumbing)
Direct Manufacturing EntityTangshan Jinjiama Prefabricated Housing Co., Ltd. (Kaiping Modern Manufacturing Zone, Tangshan City, Hebei Province, 063000, China)
Primary Export PortTianjin Port (Xingang)
Living Area414 sq ft (38.5 m²) (2 Bedrooms | 1 Finished Wet/Dry Bath Suite)
Deployed Footprint5,850 mm L × 6,280 mm W × 2,500 mm H (19.2 ft × 20.6 ft × 8.2 ft)
Folded Intermodal Envelope5,850 mm L × 2,250 mm W × 2,500 mm H (19.2 ft × 7.4 ft × 8.2 ft) (Fits standard intermodal ISO transport)
Total Empty Weight3,200 kg (7,055 lbs)
Harmonized Tariff (HS Code)9406.90.0030 (Prefabricated Steel Structures)
Lead Time & Delivery10–18 business days fabrication + 22–28 days ocean transit

2. Chassis, Enclosure & Mechanical Engineering

Structural Steel Frame2.75mm hot-dip galvanized structural steel chassis with anti-rust zinc-chromate coating
Wall Assembly & Thermal Core50mm polyurethane (PU) rigid foam thermal composite core with 0.4mm embossed steel facing
Subfloor & Finished Flooring15mm fiber-cement structural substrate with waterproof luxury vinyl plank (LVP)
Roof & Stormwater DrainagePitched galvalume steel roofing panel with built-in drainage channels; 2.0 kN/m² snow load
Glazing & Window OpeningsDouble-pane thermal break sliding windows with stainless steel mesh
Electrical Distribution110V/220V 60Hz US-spec distribution panel with dedicated 20A branch circuits
Plumbing & Sanitary Rough-InsUPC-compatible PEX-B plumbing lines, 3" PVC sanitary connection, pre-installed ceramic vanity and shower base
Wind & Snow Load Ratings120–140 mph wind load (Cat 3/4 hurricane resistant); 2.0–2.5 kN/m² roof snow load
Container Freight Plausibility2 complete folded houses fit inside ONE 40ft High Cube (40HQ) container

3. Foundation Engineering & Site Preparation

The Jinjiama Prefab Housing expandable container home requires a level, pre-engineered foundation prior to flatbed delivery. Two approved engineering methods are supported:

Option A: Reinforced Monolithic Slab (Recommended for ADUs)

  • Minimum 4-inch 3,000 PSI wire-mesh reinforced concrete pad.
  • Extended 12" × 12" perimeter turn-down footing for structural bearing.
  • Embedded 1/2" × 8" J-bolt anchors corresponding to chassis mounting brackets.
  • Provides cleanest ground clearance and zero rodent/moisture void.

Option B: 8-Point Sonotube Pier Footings (Off-Grid / Sloped Sites)

  • Eight 18-inch diameter cylindrical concrete piers with rebar cage.
  • Piers placed at 4 primary ISO container corners + 4 outer wing bearing points.
  • Depth excavated below local frost line (18"–36" depending on climate).
  • Adjustable steel screw jacks on top plates for rapid laser levelling.
FOUNDATION ANCHOR & UTILITY ROUGH-IN COORDINATES: +-------------------------------------------------------------------+ | [C1] Corner Post [W1] Wing Bearer [C2] Corner| | * Anchor Bolt (1/2" J-bolt) * Screw Jack * Anchor | | | | [UTILITY PENETRATION ZONE: 24" x 24"] | | - 3" Schedule 40 PVC Sewer Drop | | - 1/2" PEX Hot/Cold Potable Supply | | - 1.5" Schedule 80 PVC Electrical Conduit | | | | [C3] Corner Post [W2] Wing Bearer [C4] Corner| | * Anchor Bolt * Screw Jack * Anchor | +-------------------------------------------------------------------+ Length: 19.4 ft (5.9m) | Deployed Width: 21.3 ft (6.48m) | Clearance: 8"

4. Verified Inbound Customer & Contractor Response Playbook

Every question a contractor, building inspector, or prospective homeowner could ask is indexed below with verified operational and engineering answers:

5. Commercial Transparency & Sourcing Verification

Jinjiama Prefab Housing maintains direct-to-consumer contracts with our verified manufacturing partner Tangshan Jinjiama Prefabricated Housing Co., Ltd.. By eliminating multi-tier brokerage markups and utilizing direct containerized intermodal freight, we deliver complete turn-key homes at wholesale-adjacent economics.

For municipal building departments, licensed general contractors, or institutional developers requiring official factory manufacturer certificates, ISO 9001 quality audits, or structural calculation packages, contact our central engineering desk at [email protected] or call our dedicated line at +1 (833) 310-5799.

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