Cardboard (yes, cardboard) in sustainable construction

Creating sustainable building materials one box at a time

When I first heard about using cardboard in construction, it seemed absurd. I imagined another little pig in the fairy tale getting his house blown down by the Big Bad Wolf. But this paper product that is typically used to box up and ship stuff can be sufficiently strong and durable to assemble houses and other buildings.

While cardboard isn’t strong like steel or durable like stone, the paper product has advantages that make it a promising building material. First, it is sustainable, as a great deal of cardboard is made, at least in part, from recycled paper. It is also very affordable, an important factor as building costs rise.

Cardboard construction seemed like a novel ideal to me, but building things out of paper and cardboard dates back to the 8th century in Japan and has been part of Japanese interior design through the centuries. In 1867, the World Exhibition in Paris featured the first prefabricated houses made of cardboard, and prefab cardboard houses were later sold in France.

The carbon footprint of traditional construction

According to the United Nations Environment Program, buildings and the construction of buildings comprises 34 percent of energy demand worldwide and accounted for about 37 percent of CO2 emissions in 2021. The building sector alone may account for 23 percent of global emissions, which is a larger share of emissions than agriculture or transportation. Mostly through progress in efficiency, designers and engineers have reduced the carbon output from heating, cooling, and lighting our buildings, but things have lagged in finding similar reductions in construction.

Raw materials for steel and concrete must first be extracted from the earth. Both are then processed using ultrahigh temperatures, which rely mostly on fossil fuels and making both products high emitters of greenhouse gases. Producing cement for concrete generates 7 percent of global carbon emissions. For every ton of steel produced in a foundry, 2.3 tons of carbon are released into the atmosphere. Aluminum is responsible for 3 percent of anthropomorphic carbon emissions. It has been estimated that building a three-story house emits between 16 and 26 tons of CO2 or the equivalent thereof, and one estimate pegged emissions at 78 tons of CO2.

Despite an increase in energy efficiency investment and lower energy intensity, the building and construction sector’s energy consumption and CO2 emissions have rebounded from the COVID-19 pandemic to an all-time high, according to the United Nations Environment Program.

As paper and cardboard can be made from recycled material, their carbon footprint can be a fraction of steel or concrete. In some parts of the world over 90 percent of cardboard and paper are recycled. However, there are obvious drawbacks to cardboard construction. Buckling remains a problem, restricting construction to single-story and temporary structures. Cardboard is much more susceptible to water damage than other construction material, but can be treated with moisture resistant coatings—although such coatings reduce recyclability. Fire retardants are often added as well.

Recent construction from paper and cardboard

The architect most responsible for using and incorporating paper and cardboard in new construction is Shigeru Ban, who considers his work with the renewable material to be part of his commitment to creating shelters that are affordable and sustainable. In Japan in 1995, Ban created that country’s first paper-based house that relied on 110 paper tubes in its design. Ban also created what is known as the Paper Log House, which was constructed at the site of Philip Johnson’s Glass House in New Canaan, Connecticut, in 2024. Ban, recipient of the 2014 Pritzker Architecture Prize, drew up a 13.5 x 13.5-foot structure incorporating wood, paper, paper tubes, and milk crates. Ban has worked with paper construction since 1986 and thinks of the structures mostly as temporary housing for disaster victims. The design of the Paper Log House originated as shelter for earthquake refugees in Vietnam in 1995.

The Paper Log House was part of a Building Technology Course at the Irwin S. Chanin School of Architecture of the Cooper Union. Paper tubes anchored with wooden pegs make up the walls. Horizontal steel rods add support. Somehow, Ban came up with the idea of using beer crates filled with sandbags as part of the foundation. They used PVC tent material for the roof, which enabled natural ventilation and thermal control. The entire structure was coated with polyurethane varnish, which further improved thermal efficiency. It took a foreman and a team of ten volunteers only six hours to construct the house.

When we imagine a cathedral, cardboard is probably the last thing we picture in our mind’s eye, But, when an iconic gothic-style cathedral in Christchurch, New Zealand, suffered irreparable harm during a 6.3 magnitude earthquake in 2011, Ban used paper tubes to construct a replacement.

The paper cathedral in Christchurch, New Zealand

Based on a simple A-frame design, the tubes were waterproofed with polyurethane and treated with flame retardants. The paper cathedral serves the community while a permanent replacement cathedral is constructed.

In 2001, British architects in Westcliff-on-Sea used cardboard as much as possible to construct a classroom for the Westborough Primary School. The classroom is made of 90 percent recycled material and is designed to be recycled itself. It was a teaching opportunity, too, as students learned about recycling and sustainability during construction and participated in collecting cardboard for the structure. The sustainable classroom won several awards, including the 2002 RIBA Journal Sustainability Award.

And maybe if there is a cardboard construction boom, comedian Steve Martin will become a very rich man.