Standardization News

Where Traditional, Modern and Sustainable Construction Come Together

A recently revised ASTM International standard should play a part in a project to provide sustainable housing in Haiti as the country rebuilds following the January 2010 earthquake.

In post-earthquake Haiti, as the discussions of appropriate home rebuilding begin, what does it mean that we respond with tents and plywood structures as temporary solutions that for many become long term? With more than 1.2 million Haitians in need of shelter in the short term and adequate housing in the long term, we bring resources from our developed nations that are nearly impossible to find regionally.

Instead of offering merely supplies, what if we could offer our ingenuity? What if we could look together as globalized citizens with all that our collective minds have to offer to improve the lives of those who are hungry for development, without replicating unsustainable systems? As the rock dust settles, alliances are forming among the various relief groups in order to join creative forces to discover sustainable ways to help Haitians help themselves.

One such group, officially known as the Technical Working Group on Local Materials in Construction and informally known as the "Co-laboratory," has formed out of a larger group of various experts to explore using local materials in construction, but learning how to engineer them to withstand natural disasters well enough to protect the life inside. It began when UN-HABITAT (the United Nations agency for human settlements, which promotes socially and environmentally sustainable towns and cities) asked Kleiwerks International to co-chair the technical working group along with the National Laboratory for Building Materials and Public Works. The goal is to help identify opportunities for providing housing, using materials accessible to Haitians in various sectors, from urban to rural. Given the damage sustained in the 7.0 earthquake to buildings made of concrete and masonry, there is an obvious and urgent need to improve the technology.

Traditional Meets Modern

In looking at other post-disaster development, such as that in Pakistan after the earthquake in 2005, the international community learned that it is necessary to focus on improving traditional building technologies. These technologies are economically accessible to much of the population and rely on local, renewable resources. In the past 20 years, much research has been conducted on the performance of traditional materials such as earth, which is used extensively in Haiti's housing in rural, peri-urban and urban areas. Many buildings in Port-au-Prince and in the outlying rural areas are constructed partly or entirely of earth.

Shortly after the earthquake in Haiti, an 8.8 earthquake hit Chile. While the earthquake in Chile was larger than the one in Haiti, more buildings remained standing. The general conclusion was that Chile had building codes for concrete and that Chilean builders followed those codes. Haiti had few or no codes, and there were no best practices for building in Haiti. What if Haitian builders and owner-builders had guidelines to follow that were written for the materials they were more likely to use? In this case, that would mean earthen materials, such as can be found in the colombage-style (wood frame with masonry infill) houses in Port-au-Prince. An international building standard for earthen buildings - and other vernacular styles - would be very helpful to have in Haiti, and in other developing and recovering places.

In order to develop guidelines or standards, Kleiwerks International has proposed to UN colleagues that the co-laboratory should investigate traditional architectural styles that utilize materials other than cement. Their goals would be, first, to collect the data, and second, to come up with standards and best practices that combine the sensibility of the vernacular with the ingenuity of the modern to create aesthetically pleasing, climate-appropriate, economically viable, energy-efficient and resilient housing, using locally available materials and techniques.

Modern Meets Traditional

An ASTM International standard, E2392/E2392M, Guide for Design of Earthen Wall Building Systems, from ASTM Committee E60 on Sustainability, was recently updated in an effort led by the Ecological Building Network and its founder, Bruce King, who says, "A number of great engineers around the world have worked out how to build seismically safe earthen buildings, really for the first time in history, and it seemed the best way to get that knowledge out was to develop and publish a recognized standard."

Now that the ASTM standard recognizes that earth is a measurable building material, the organizations concerned with rebuilding can share standards and best practices with builders in places such as Haiti, where it is a more practical choice than concrete, for example. Experienced practitioners of vernacular building techniques can teach owner-builders and contractors safe and affordable ways of using it to build or to rebuild. With this kind of validation, government officials and decision makers who have the power to distribute what funds have come through for rebuilding can have more confidence in the official document if they don't have technical knowledge or experience of building systems. That validation is referred to in the section of the standard on earthen construction:

Building Code Impact - Earthen building systems have historically not been engineered, but as of the late 20th century, it is for the first time in history possible to reliably apply rational structural design methods to earthen construction. A large number of earthen building codes, guidelines and standards have appeared around the world over the past few decades, based upon a considerable amount of research and field observations regarding the seismic, thermal and moisture durability performance of earthen structures … This guide draws from those documents and the global experience to date in providing guidance on earthen construction to engineers, building officials and regulatory agencies.

One interesting discovery that structural engineers observe since the Haiti earthquake about the concrete buildings that failed is that, while they should have been of high compressive strength, they were actually made of inferior material and were measured after the earthquake at very low compressive strength. And when tested, a lot of the earthen building materials fell in at a lower strength ratio as well. To get around this insufficiency of compressive strength in earth, there are reinforcing technologies designed for earthen buildings that make it possible to use this weaker building material to create durable natural buildings. These reinforcing technologies, such as the use of bamboo for tensile strength, could be applied to weaker mixes of concrete in situations where rebar as reinforcement is too expensive.

It should be possible to improve those poorly constructed concrete buildings without having to mimic what we have done in the developed world. Simply put, if you can use bamboo to reinforce an earthen building (this has been officially documented), you can also use bamboo to reinforce poor-quality concrete. This could be a temporary or a permanent solution, and with similar innovation, other materials than bamboo that are readily available in Haiti could be used in reinforcement. The innovation is to stop looking at concrete as a conventional building material and to start looking at how the Haitians are really using it. And then to design solutions based on this use in the real world.

Developed Meets Developing

The co-laboratory has designed an initial project that will take place over a period of six months. This project is divided into three phases and will identify and promote methods that:

Phase 1: Assessment

The first phase will focus on studying traditional home construction in rural, peri-urban and urban regions, where the building methods were based on local materials. There are many documented examples of such buildings using earth and stone. Some of the research is already being compiled by members of the co-laboratory, who studied gingerbread-style houses in the urban area of the capital city, Port-au-Prince. This team of engineers, architects and builders is conducting a project to preserve these historical buildings. The project is funded by the World Monuments Fund, the Prince Claus Fund, Foundation FOKAL (La Fondation Connaissance et Liberté), and UNESCO (United Nations Educational, Scientific and Cultural Organization). The co-laboratory hopes to broaden the assessment research beyond historical preservation to include some of the other 12 identified building styles that utilize earth in modern construction. This phase will culminate in a database of findings, which will be available to other organizations, and a preliminary report on those findings.

Phase 2: Technical Improvement

Through collaboration with national and international building trades experts, the team will begin to draft opportunities for improving local materials based on recent international code specifications, including the ASTM International earthen building standard. This will mean doing a series of collaborative workshops (to take place in Haiti) with design teams and community representatives from sample communities, as well as ministry, UN and partner nongovernmental organizations, all of whom will teach whatever they bring to the table. The co-laboratory will conduct tests of traditional materials in conjunction with the Haitian national materials laboratory. At the end of this phase, the findings of the preliminary tests will be made public.

Phase 3: Dissemination

The workshops will culminate in the development of a summary containing best practices and standards for teaching builders best methods for combining traditional with modern materials. This phase, lasting about two months, will include the publication of a basic training manual and a series of workshops for architects, builders and other stakeholders. This manual will be based on the findings and conclusions of the research. The trainings will be tailored to groups with the highest potential to adhere to, further disseminate and perhaps even evolve the technical findings. The structure of reporting will be guided by UN-HABITAT, which will facilitate that dialogue with the Haitian government concerning incorporation of the study findings into guidelines and best practices.

By working with Haitians up front and along the route, the co-laboratory and other relief groups like it are learning from Haitians, who are bringing their understanding of the local customs, culture and traditional building methods to the table, while the co-laboratory brings its members' knowledge of standards writing and engineering to bear on builders in Haiti, to achieve a true collaboration. It is worth noting that female professionals will be included in each phase of the project to ensure that the results reflect the population as a whole and therefore lead to a more credible and realistic end product.

Following the conclusion of the project, there may be an opportunity to expand the materials and scope of the training by helping the trainers to improve their skills and by continuing to support local builders as projects get under way. The creation of standards and best practices in building could lead to a thriving culture of owner-builders, trades and schools, and to an evolution of vernacular architecture, marrying what worked in the past with what is possible with modern building innovation. It's an opportunity for the entire country to grow and possibly a chance for developing nations to leapfrog over our mistakes in the developed world.

Kevin Rowell is program director for Kleiwerks International and owner of The Natural Builders, a licensed California contracting company.

Leslie Jackson is associate editor of Home Energy.

©2010 Home Energy. Reprinted with permission from the publisher.