Container House

A container house is a building made wholly or largely from steel intermodal shipping containers, the standard boxes that carry freight by ship, rail and truck. Designers cut, stack, join and insulate the containers so that each steel box becomes structure, enclosure and room module at the same time. The idea is used for homes, student housing, studios and offices, and it rewards careful engineering far more than its simple image suggests.

What is a container house?

The starting point is a mass-produced object with fixed dimensions. Most freight containers are nominally 20 or 40 feet long, and standard boxes are 8 feet wide by 8 feet 6 inches high, with a taller "high cube" version at 9 feet 6 inches, as summarised in the Wikipedia overview of intermodal containers and the ISO 668 standard. Each box has a steel frame with eight corner castings built to carry stacking loads, and corrugated weathering steel walls that stiffen the whole shell. A container house is any building that adopts this box as its primary structural and spatial unit, whether it uses one container as a cabin or dozens as a block of flats.

That definition separates it from its neighbours. Modular housing covers factory-built volumetric units of many kinds, most of them designed as buildings from the outset; a container house reuses, or imitates, a box designed for cargo and then adapts it. Compact living is about how people organise small interiors, which matters inside a container but applies equally to apartments and cabins. And modular design is the wider method of building from repeated parts. The container house sits where all three meet, with one distinctive constraint: the module arrives with its width, its structure and its steel skin already decided. Members also collect related work under shipping containers. In practice the term covers a wide range, from a single converted box used as a garden studio to stacked residential blocks where containers are hidden behind cladding and only their dimensions remain.

A short history of container houses

Container architecture only became possible once the container itself was standardised. Malcom McLean's container ships in the United States in the 1950s began the shift to boxed freight, and the international standard sizes that followed meant that identical steel boxes existed in huge numbers around the world. By the 1980s some of them were being looked at as building material rather than packaging.

A clear early milestone is a United States patent filed by Phillip C. Clark on 23 November 1987 and granted on 8 August 1989 as US 4,854,094, a method for converting steel shipping containers into a habitable building. The patent already describes the moves designers still make: setting containers on a foundation at their ends, placing them side by side or on top of one another, adding a roof, a raised floor and a dropped ceiling, and cutting doors and windows into the walls.

"Where containers are mounted side-by-side, portions of the inner sidewalls are removed leaving at least narrow flanges extending inwardly from the edges thereof."

Phillip C. Clark, US Patent 4,854,094 (1989)

The best-known built example in Europe came from Urban Space Management in London. According to the practice's own page, Container City I at Trinity Buoy Wharf was designed and built with Nicholas Lacey Architect, engineered by Buro Happold and completed in five months in 2001, providing 12 work studios, with a fourth floor of live/work apartments added in 2003. Container City II followed on the same wharf.

Scale arrived soon after. The Wikipedia history of shipping container architecture records that in 2006 the Dutch company Tempohousing finished a container village of 1,000 student homes in Amsterdam, a precedent that still shapes how architects think about containers for students. Building codes have since caught up: the 2021 International Building Code includes a section on intermodal shipping containers repurposed as buildings.

Key principles of container house design

Respect the frame

A container is strong where it was designed to be strong: at the corner posts and castings, which carry the weight of a full stack at sea. The corrugated walls and roof add rigidity, but the roof is not built for heavy loads. Every large opening removes part of that stiffening skin, so serious projects frame cut openings in steel and have an engineer check the whole assembly. Stacking works best when corners land on corners.

Design for addition and removal

Containers are made to be lifted, moved and reassembled, and good container buildings keep that ability. CONTAINER CITY by Bersu Başaranoğlu, Merve OZUBEK and sümeyye şahin takes the idea literally: it proposes reusing cranes in the process of reusing containers, so the structure stays addable and removable as demand grows, leaving an open-ended process rather than a finished object.

Plan around the narrow box

A standard container is only about 2.4 metres wide outside, and less inside once it is lined. Single-box plans become corridors, so most good container buildings combine boxes, remove inner walls between them, or use the gaps between containers as rooms, decks and circulation. The team behind Student housing from containers (Tanya Prevezentseva, Влад Василевский and Evgeny Lagodnyy) made this their main focus, using the placement of the containers relative to each other to win usable free space.

Insulate and control condensation

Steel conducts heat very well, so a container house in a climate with real temperature swings needs more insulation than a comparable brick, block or timber building. Moist interior air that meets cold steel condenses and starts rust unless the steel is sealed and insulated. Designers choose between lining the inside, which eats into the narrow width, and wrapping the outside, which hides the corrugated skin but keeps the steel warm and the interior generous.

Treat floors and coatings as suspect

A used cargo box was never meant to be lived in. To meet Australian quarantine rules, many container floors are treated with insecticides containing copper, chromium and arsenic, and paints and sealants applied in manufacture may also be harmful. For habitation the timber floor should be removed and replaced, and interior coatings are stripped or sealed before any finish goes on.

Container houses on uni.xyz

Much of the container work on uni.xyz comes from the Container City competition, and most of it is housing for students: a programme where short stays, repeated rooms and tight budgets suit a stackable module. The projects below show how differently members handle the same box.

Verzendaccommodatie by Antonio Abreu and Phillip Tu received an Honorable Mention in the Container City competition. It is a modular student housing concept for the Amsterdam University College built from 15 shipping containers, a fitting site given the city's history with container student homes.

HABITAT Student Housing by Cristina Pérez Cámara, another Honorable Mention in the Container City competition, sets out to be affordable, sustainable and modular while giving a healthy community living space on a small footprint of land, including for residents with accessibility needs. That last point matters, since narrow boxes and stacked levels can easily shut out wheelchair users.

WARTA CAMP by Jagna Przybylska, also an Honorable Mention in the Container City competition, places student housing near the Warta riverfront and frames the project as a response to the global problem of waste, which is the strongest argument for reusing containers at all.

CONTAINER CITY by Phúc Thái, a further Honorable Mention in the competition, distils its idea into a single line: life in a modular unit. Marine Laboratory Housing by chihyun tseng and 晨瑄 李 gives the type an institutional twist. Students on marine biology courses who research at sea all day lacked facilities, so the team combined a dormitory near the university with spaces that support those courses.

Agora by Claudia Lévesque treats its container city as a gathering place, aiming to encourage social life inside the student residences and also at the scale of the neighbourhood. StuCOMM by Jennifer Lee states the brief that every entry in this group is really answering:

"In our exploration we aimed to create a structure that was both modular, cost effective, and replicable without taking away from the quality of life of a space."

Jennifer Lee, StuCOMM, project statement on uni.xyz

Read together, these projects show the type at its most useful: repeated rooms, shared ground between boxes, and a building that can grow or shrink with its population.

Challenges and future directions

The honest case for container houses is narrower than the marketing. The shell is cheap and strong, but the work of making it habitable is not: cutting and framing openings, adding insulation and a roof, replacing floors, and bringing in services can absorb much of the saving.

Regulation is the second hurdle. Permits can be difficult where local officials are unfamiliar with steel boxes used as homes, and codes now ask for proof. The Matanuska-Susitna Borough in Alaska, for example, applies 2021 IBC Section 3115 to containers repurposed as buildings and requires a structural analysis showing that the containers are adequate. That is a reasonable demand for a box whose walls may have been partly removed.

The most promising directions use containers where their strengths count: temporary and relocatable housing, student and key-worker rooms, site offices that later become homes, and buildings designed from the start to be taken apart. The weakest use is the single luxury house that hides every trace of the box behind cladding. The question worth asking at the start of any project is simple: does the container solve a real problem here, such as speed, relocation or reuse, or is it only an image?

Container houses for students and designers

Containers make an excellent studio exercise because the constraints are fixed and real. Good thesis angles include a stacking and disassembly strategy for a site with a limited lease, a climate study comparing internal and external insulation, a student housing block that plans for accessibility from the first sketch, or an honest cost and carbon comparison against a timber module. Browse student housing for programme precedents, and look for live briefs on uni.xyz competitions where a container or modular entry can be tested against other approaches.

Frequently asked questions

Are shipping container homes cheaper than conventional houses?

The container itself is inexpensive, but conversion work (openings, framing, insulation, new floors, roofing and services) adds up quickly. A container house can save money when the design keeps boxes whole and repeats them, and much less when it cuts them heavily.

How do you insulate a container house?

Because steel conducts heat so well, insulation is essential in most climates, and it also prevents condensation and rust on the inside face of the steel. It can go inside the box, which reduces the narrow width, or outside, behind a new cladding layer.

Do container homes need building permits?

In most places, yes. A container used as a building is treated as a building, and in the United States the 2021 International Building Code includes a section on repurposed intermodal containers. Expect to provide engineering for cut openings and stacking.

What is a shipping container city?

The term usually describes a cluster or stack of container units forming a small neighbourhood, often studios, student rooms or workspaces. London's Container City buildings at Trinity Buoy Wharf are the best-known example.

How tall can you stack containers in a building?

Containers are designed to carry stacking loads through their corners, so multi-storey container buildings are common. The practical height depends on the openings cut, the loads, wind and fire rules, and must be confirmed by a structural engineer for each project.

References and further reading

• Shipping container architecture, Wikipedia
• Intermodal container, Wikipedia
• US4854094A: Method for converting one or more steel shipping containers into a habitable building at a building site and the product thereof, Google Patents
• Container City 1, Container City (Urban Space Management)
• Intermodal Shipping Containers, Matanuska-Susitna Borough