Designing Modern Wood Schools

Sponsored by Think Wood
1.5 AIA LU/HSW; 1.5 GBCI CE Hour; 0.1 IACET CEU*; 1 PDH*

Learning Objectives:

  1. Review provisions of the International Building Code specific to school buildings and discuss opportunities to achieve cost savings through the use of wood.
  2. Explore design and detailing best practices used to achieve performance objectives in school assembly design.
  3. Discuss structural design considerations unique to school buildings, as well as framing options for floors, walls, and roofs.
  4. Consider how wood has been used in modern wood-frame and mass timber schools across the United States.

This course is part of the Wood Structures Academy

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Energy Efficiency

For the Bethel School District, energy efficiency is an objective because of the cost savings. However, it underscores wood’s benefits from a thermal performance perspective.

Between 2004 and 2011, the district reduced its energy use by more than 7.6 million kilowatts and saved $4.3 million in utility costs—equivalent to the cost of electricity for 15 of its elementary schools for one year. It reported an 81 percent ENERGY STAR rating overall, and several of its 17 elementary and six junior high schools had a rating of between 95 and 98 percent. All of these schools are wood-frame.

Wood-frame building enclosures are inherently more efficient than steel-frame, concrete, or masonry construction—because of the insulating qualities of the wood structural elements, including studs, columns, and beams, and because wood stud walls are easy to insulate.9 Options also exist for insulating wood-frame buildings that aren’t available for other construction types. For example, while requirements for lighting systems or mechanical systems do not change based on structural material, wood’s versatility related to building envelope configuration gives designers more insulation flexibility.

Continuous insulation is often specified as a stand-alone prescriptive requirement or, alternatively, in conjunction with nominal insulation (e.g., between wood studs) in order to achieve higher effective R-values. Continuous insulation is necessary in structural systems using concrete and steel, which have high rates of thermal bridging, but is often avoidable in wood-frame envelopes.10


Environmental Performance

School boards, whether they receive funding from public or private sources, often include environmental performance in their objectives for school design.

In addition to the fact that wood grows naturally and is renewable, wood has a lighter carbon footprint than other common building materials.

As trees grow, they absorb carbon dioxide from the atmosphere, storing the carbon in their wood, roots, leaves or needles, and surrounding soil, and releasing the oxygen back into the atmosphere. When trees start to decay, or when the forests succumb to wildfire, insects, or disease, the stored carbon is also released. However, when trees are harvested and manufactured into products, the products continue to store much of the carbon. In the case of wood buildings, this carbon is kept out of the atmosphere for the lifetime of the structure, or longer if the wood is reclaimed and manufactured into other products. In any of these cases, the carbon cycle begins again as the forest regenerates and young seedlings once again begin absorbing carbon dioxide.

The fact that manufacturing wood into products requires less energy than other materials (and very little fossil fuel energy) also contributes to its relatively light carbon footprint.11

Life-cycle assessment (LCA) studies consistently show that wood outperforms other materials in terms of embodied energy, air and water pollution, and global warming potential.12 LCA is an internationally recognized method of evaluating the environmental impacts of materials over their life cycles, from extraction or harvest of raw materials through manufacturing, transportation, installation, use, maintenance, and disposal or recycling. It is increasingly being integrated into green building rating systems as a way to compare the impacts of alternate building designs.


Health and Well-Being

As green building objectives have come to embrace human health issues, a growing number of studies have linked the use of exposed wood with occupant well-being.

For example, an Austrian study found that interior wood use in classrooms reduced pupils’ stress levels, as indicated by criteria that included heart rate and perceived stress from interaction with teachers.14

Similarly, a 2012 study at the University of British Columbia and FPInnovations demonstrated that the presence of visual wood surfaces in a room lowered sympathetic nervous system (SNS) activation.15 The SNS is responsible for physiological stress responses in humans.

Building on this study, the 2015 report, Wood as a Restorative Material in Healthcare Environments, reviews available research on the human response to natural elements in the built environment.16 The report states: “In the small but growing volume of research on wood and health, the results that are emerging mirror results we have seen from exposure to other natural elements, such as views and plants. Lower stress reactivity in the autonomic nervous system is found when wood, plant, or nature views are present. Lower sympathetic activation and higher parasympathetic activation result in measurably lower heart rate, lower blood pressure, lower skin conductivity, and higher heart rate variability. These results have been linked to exposure to wood. However, lower stress activation due to views and plants have also been shown to increase the ability to concentrate, lower pain perception, and speed recovery times. Though these benefits have not been identified for wood, they are tied to the same automatic responses to nature seen with wood. Therefore, it is reasonable to expect that future research on wood will find many of these same results.”

One of the most promising areas of focus is evidence-based design, which involves using information gained from the analysis of past buildings to build better new ones. Health-care architects have been at the forefront of this effort, exploring the physiological benefits of good design on patient recovery and the well-being of staff and visitors. Among the results, an increasing number of health-care facilities are making use of natural daylight, views of nature, and exposed wood to create warm, natural aesthetics that support their healing objectives. These same techniques are also being used in schools and offices to improve performance, productivity, and occupant well-being.


Conclusion

If there is a generalization to be made about the design of educational facilities, it is that architects are often called upon to achieve many objectives with limited budgets. This may be wood’s greatest strength in the context of schools—that it typically costs less, while performing structurally and offering benefits that cover the gamut from design flexibility to carbon footprint to occupant well-being. This may also be the reason we see more wood schools over the next decade, as U.S. designers seek to satisfy the needs of a growing student population.


End Notes

1School Planning & Management State of School Construction, 2015 Report

2National Center for Education Statistics, Projections of Education Statistics to 2024, http://nces.ed.gov/pubs2016/2016013.pdf

3Case Study: Bethel School District, WoodWorks, http://www.woodworks.org/wp-content/uploads/CS-Bethel2.pdf

4Case Study: El Dorado High School, WoodWorks, http://www.woodworks.org/wp-content/uploads/CS-El-Dorado.pdf

5Acoustical Considerations for Mixed-Use Wood-Frame Buildings, WoodWorks, http://www.woodworks.org/wp-content/uploads/Acoustics_Solutions_Paper.pdf

62015 National Design Specification® (NDS®) for Wood Construction, Section 2.3.2.1, American Wood Council

7ASC Steel Deck Floor Deck Catalogue, http://www.ascsd.com/files/floordeck.pdf

8ASCE 7-10: Minimum Design Loads for Buildings and Other Structures, Table C3-1

9Guide for Designing Energy-Efficient Building Enclosures for Wood-Frame Multi-Unit Residential Buildings in Marine to Cold Climates in North America, 2013, FPInnovations

102012 International Energy Conservation Code, Table C402.2

11A Synthesis of Research on Wood Products and Greenhouse Gas Impacts, FPInnovations, 2010

12Werner, F. and Richter, K., Wooden building products in comparative LCA: A literature review; International Journal of Life Cycle Assessment, 12(7):470-479, 2007

13Back to Nature: Can wood construction create healthier, more productive learning environments, Building Design + Construction, 2005

14C. Kelz1,2, Grote V.1,2, Moser M.1,2, Interior wood use in classrooms reduces pupils’ stress levels, 1Institute of Physiology, Medical University of Graz, Austria; 2HUMAN RESEARCH, Institute for Health, Technology and Prevention Research, Weiz, Austria

15Wood and Human Health, FPInnovations, 2012

16Wood as a Restorative Material in Healthcare Environments, FPInnovations, 2015



“Think

Think Wood is a leading education provider on the advantages of using softwood lumber in commercial, community and multifamily building applications. We introduce innovators in the field to our community of architects, engineers, designers and developers. For support or resources, contact us at info@ThinkWood.com.

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Originally published in Architectural Record


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