Those who view concrete as good point out that it has a wide range of uses and it has been an incredible tool for the construction industry over the years. It is a traditional material that people know how to work with, it is rather inexpensive, and it can be used in all sorts of ways. Many acknowledged that concrete has a role to play in construction for certain types of buildings, certain heights, and certain parts of the world where concrete is widely available.
But should concrete be used for housing, and more specifically, for affordable housing? Many said no, specifically because of the environmental downsides. Cesar Martinell, who had just given a keynote on the Past, Present & Future of Construction, made a convincing case that, “Concrete is a disaster for ecology.” Concrete requires cement, which requires energy at all stages of production, from extracting the rock to burning it, molding it and then mixing it. Then it takes large amounts of water to bind, water which simply evaporates away, wasting one of our most precious resources. Other downsides of concrete include quality control issues, vulnerability in earthquakes, and the fact that it loses strength over years.
So if concrete isn’t the solution to the affordable housing crisis, what is? Some attendees mentioned using alternative forms of concrete, such as aerated concrete and recycled concrete. There were many other materials suggested to. The most discussed were:
Wood – A renewable material that is easy to build and can achieve very high quality. Low prices mean that it can work for affordable housing, but there are also durability issues because wood houses can rot.
Recycled Steel – Steel is one of the most recycled materials and using it is better for the environment. One panelist even pointed out that, in terms of weight, you use less steel in creating a house without concrete than a house with concrete.
Around the globe, attendees from various countries were also experimenting with other construction alternatives, including structural insulated panels, engineered composite boards, recycled & recyclable plywood boards, bamboo, and composites.
Perceptions Slow the Adoption of Alternative Materials
Although alternative materials are available, people in various countries around the world have been wary about embracing them. This demonstrates that although many builders and engineers are interested in finding more sustainable materials, individuals still cling to brick and mortar as the housing standard.
Part of this is aspirational – people associate concrete houses with success, and in their climb to reach a middle-class lifestyle, alternative materials are an unworthy substitute. Part of it is cultural as well. People want to reside in a house that looks like the ones they see in their cities and neighborhoods or in the movies. There are also lower perceptions of quality in alternative materials (that is, if you knock on the wall and it sounds hollow, it must not be sturdy enough). What all of this boils down to is the fact that buying a house is an emotional decision, not a logical decision. People want affordable houses, but if the construction doesn’t match up with their pre-conceived ideas of what a house should be, they’re not going to be sold.
Exploring Solutions in Design and Construction
The panel highlighted the challenges to design and construction, including costs, materials, availability, accessibility, the environment, perceptions, and more. There is clearly no quick fix, but panelists and attendees did suggest a number of solutions, including:
Embracing recycled, reused or repurposed materials and other material options that have a lower impact on the environment.
Using local materials, which can support the local economy and cut down on the impact of shipping.
Exploring the benefits of pre-fabricated modular design, where houses can be constructed off-site, leading to time and money savings that can make housing more affordable.
Understanding the local market in order to provide individuals with the type of housing they want, including where houses should be built and how to blend the benefits of modular design with the customization that younger generations are looking for.
There was also a clear enthusiasm and excitement for what the future holds in terms of new materials and construction methods. In the past, we relied on ‘tried and true’ materials like concrete and steel and so we weren’t motivated to find new solutions. All of that is changing. Technology is advancing at a rapid pace, and researchers are now exploring new materials to use in construction. What will unfold in the next 5-10 years is probably something we would never have guessed or dreamed of today.