20ft High-Cube Container De Lux Bungalow 20′
A spacious single-bedroom layout with modern interior appointments, expansive window walls, and full kitchen amenities.
1 Bedroom1 Bathroom517 Sq Ft
Oregon CCB# 187113 · Washington CL# RELEVBC785L9
ADU Builder in Portland, Oregon
Engineered Prefabricated Shipping Container ADUs & Modular Housing Solutions for Global Procurement & Residential Projects
ISO Corten SteelUpcycled high-strength structural framing
State Insignia ApprovedFully code-compliant & insurable builds
R-Value Thermal EfficiencyClosed-cell spray foam insulation exceeds code
Turnkey LogisticsIntermodal shipping & factory-built quality
Factory Precision FabricationReduced site build times & structural longevity
Prefabricated Housing Engineering
Engineered Container ADUs for Modern Housing & Development
Relevant Buildings is a premier licensed ADU builder headquartered in Oregon, specializing in off-site modular manufacturing using upcycled ISO Corten steel shipping containers. We engineer high-performance Accessory Dwelling Units (ADUs), guest houses, rental units, and commercial workforce accommodation built to stringent structural and environmental standards.
Our factory-controlled modular build process allows concurrent site preparation and structural framing. This eliminates weather delays, reduces construction waste, and delivers fully completed residential units ready for quick site placement across domestic and international markets.
- Certified Structural Compliance: Manufactured with official State Insignias ensuring compatibility with IRC, IBC, Oregon BCD, and Washington L&I codes.
- Streamlined Supply & Logistics: Intermodal container dimensions allow cost-effective transport via ocean freight, rail, and heavy tilt-bed trailers worldwide.
- High Thermal & Seismic Performance: Closed-cell polyurethane foam insulation and rigid steel framing provide superior resistance to fire, earthquakes, pests, and extreme climates.
Standard & Custom Specifications
Popular Modular Container ADU Models
Explore our standardized 20ft, 40ft, and multi-container floor plans engineered for space optimization, rental yields, and sustainable living.
20ft High-Cube Container 
20ft High-Cube Container De Lux River 20′
Designed with bump-out architecture for expanded living area, optimized natural light, and premium energy-efficient HVAC.
1 Bedroom1 Bathroom599 Sq Ft
40ft High-Cube Container Suite Spot River 40′
A full 40ft footprint featuring an independent private bedroom, dedicated office space, and luxury bathroom fixtures.
1 Bedroom1 Bathroom663 Sq Ft
40ft Single Container Ramona 40′
An efficient single-container floor plan tailored for narrow suburban lots, backyard rentals, and guest accommodations.
1 Bedroom1 Bathroom453 Sq Ft
Multi-Container Modular De Lux River 40′
Our flagship multi-container configuration engineered for full-time family living, dual master suites, and commercial applications.
2 Bedrooms2 Bathrooms1,148 Sq Ft
20ft Studio ADU SADU City 20′
Ultra-compact studio unit designed for urban infill sites, executive home offices, or high-yield short-term rental properties.
Studio1 Bathroom318 Sq Ft
Manufacturing Rigor & Quality Control
High-Performance Insulation & Anti-Corrosion Systems
High-Density Closed-Cell Spray Foam Insulation
We isolate the internal living environment from the outer steel skin using continuous closed-cell polyurethane spray foam. This creates an airtight vapor barrier, eliminates thermal bridging, and provides insulation values exceeding building code minimums by more than 10%.
Condensation Control & Moisture Protection
Only non-hydroscopic, inert structural materials contact the Corten steel hull. Integrated Energy Recovery Ventilators (ERVs) maintain balanced air exchanges, controlling indoor humidity and ensuring healthy indoor air quality year-round.
Industrial Exterior Marine Coatings
Exterior steel surfaces are prepared and sealed with commercial-grade marine epoxy primers and UV-resistant topcoats, providing decades of protection against salt air, heavy rain, and extreme weather.
| Feature | Specification | Operational Advantage |
|---|---|---|
| Structural Frame | Heavy-Duty Corten Steel (ISO standard) | High seismic & hurricane wind load resistance |
| Insulation Type | 2.0 lb Closed-Cell Polyurethane Foam | Complete vapor barrier, R-21+ walls, R-30+ roofs |
| HVAC System | Ductless Inverter Heat Pump Mini-Splits | Energy-efficient zonal heating & cooling |
| Ventilation | Energy Recovery Ventilator (ERV) | Continuous fresh air filtration & moisture management |
| Code Certification | Oregon BCD / Washington L&I Insignia | Fully permit-ready, bank financable, insurable |
| Exterior Finish | Marine Coating / Engineered Timber Cladding | Low maintenance, high weather durability |
Detailed engineering packets, structural calculation stamps, and BIM models are available for commercial procurement partners upon request.
Installed Projects
Finished Container ADUs & Modular Builds
Examine completed modular installations across urban, suburban, and coastal landscapes.
Technical & Procurement FAQ
Frequently Asked Questions
Key information for property owners, developers, and international procurement buyers evaluating prefabricated container ADUs.
What is a prefabricated container ADU?
An Accessory Dwelling Unit (ADU) built from ISO steel shipping containers is a fully self-contained secondary home. Manufactured in a factory environment, it includes full residential amenities such as kitchen cabinetry, bath fixtures, wiring, plumbing, and climate control, delivered pre-built to the installation site.
Are container ADUs fully code-compliant and insurable?
Yes. Relevant Buildings manufactures structures carrying official State Insignias for modular prefabricated buildings. They meet International Residential Code (IRC) and International Building Code (IBC) standards, permitting standard mortgage financing, appraisal, and property insurance coverage.
How do factory-built ADUs compare to traditional site-built timber construction?
Factory manufacturing reduces on-site construction timelines by up to 50% through simultaneous site development and off-site modular framing. Steel construction also eliminates vulnerability to wood rot, termites, fire propagation, and structural sagging over time.
Do you export units internationally or handle large-scale commercial orders?
Yes. Because our units are built within standard intermodal ISO shipping container geometry, they are engineered for ocean vessel shipping, rail, and highway freight. We support multi-unit commercial orders for resorts, workforce housing, and residential development projects worldwide.
How are condensation, extreme temperatures, and rust prevented?
Units feature seamless closed-cell spray foam insulation applied directly to interior steel corrugations, completely preventing thermal transfer and vapor condensation. Exterior surfaces are coated with commercial epoxy marine paints and optional pitched secondary roofing systems.
Start Your Container ADU Project Today
Connect directly with our engineering and sales team for architectural consultation, custom specifications, and commercial procurement inquiries.