Building Science Our Construction Consultants Use

SECTION 1: BUILDING SCIENCE DEFINED

Building science is a field of knowledge that draws upon physics, chemistry, engineering, architecture, and the life sciences. Understanding the physical behavior of the building as a system and how this impacts energy efficiency durability, comfort, and indoor air quality is essential to innovating high-performance buildings. Modern building science attempts to work with models of the building as a system and to apply empirical techniques to the effective solution of design problems. Our building envelope specialists can apply their knowledge of building science to the work they do at BES.

More specifically, contemporary building science is a broad discipline that is concerned with the full life cycle of buildings, including:

• Policy (codes and standards)
• Planning
• Design
• Construction
• Commissioning
• Facilities maintenance
• Forensics and rehabilitation
• Restoration retrofit
• Preservation and conservation
• Demolition (deconstruction) and recycling

The disciplinary involvement in contemporary building science ranges from the physical and engineering sciences to economics, political science, behavioral sciences, life sciences, and architecture.

The importance of contemporary building science is often fully appreciated after the occurrence of building performance problems, or worse, after failures, rather than at the planning and design stage of building projects. For this reason, contemporary building science has taken on greater importance in response to an increasing trend of innovative departures from traditional building practices based on successful past precedents.

SYSTEMS APPROACH

Innovation is not a trial and error process that relies on gradually refining past precedents. It is usually a significant departure from normative practices and relies on the scientific method to advance its agenda. Modern building science, as it is known today, was born of innovation — more correctly, because of the large number of failures encountered when building designers attempted to innovate without applying building science principles. There was no need for building science when only successful precedents were copied and handed down from one generation to the next, but there was also no advancement toward high-performance buildings within traditional building practices. With the help of Building Enclosure Specialists, you can rest easy knowing you have building science experts overseeing your project.

There exist millions of buildings and their diversity would be overwhelming were it not for the systems approach. This approach is derived from general systems theory and the basic characteristics common to all systems are important to keep in mind when applying building science.

• Boundaries and Boundary Criteria—Many people believe that a building system ends at the outer surface of its enclosure, in some cases at the property line. But in reality, the building system extends to the outer reaches of what it impacts and what impacts the building. Basement flooding due to municipal sewer surcharge is an example of the building’s plumbing system extending to the local municipal infrastructure services.
• Flows and Storage—Inhabitants, energy, water, sewage, and data are examples of the flows and storage characteristics of the building as a system. Occupant behavior is among the most difficult flows to accurately predict in energy models.
• Transformations—Buildings age and they are modified by their users, not always in a beneficial way. It is desirable from a life cycle perspective to design buildings that can adapt and adopt new technologies to improve their performance and minimize functional obsolescence.
• Spatial and Temporal Hierarchies—Passive survivability and safe and secure building design are premised on achieving spatial and temporal resilience such that the vital functions are maintained both in day-to-day operations and under extreme conditions such as natural and man-made disasters.
• Feedback and Control Loops—Buildings are prosthetic extensions of the human body and as such rely on many forms of cybernetics to control the indoor environment and maintain safety and security.

Each of the above characteristics varies in importance, depending on the type of building being designed and its intended use. Building science specialization is often needed to deal with particular aspects of these characteristics (e.g., energy modeling, floodproofing, durability, indoor air quality, blast resistance, etc.). But in all cases, the fundamental understanding of how these characteristics interact may be derived from the building as a system model, and that’s where our building envelope consultants can help.

BUILDING PERFORMANCE

The term “performance” may be defined as the level of service provided by a building material, component, or system, in relation to an intended, or expected, threshold or quality.

When the intended or expected level of performance is not achieved, the resultant behavior is termed a “failure” which must not be confused with the term “defect”, a minor damage or blemish which has no immediate or significant impact on performance, and which may be suitably repaired.

An important contribution of building science is the quantification of performance parameters such that many of these can be predicted at the design stage and assessed/confirmed after the building is occupied and operational. This preoccupation with prediction and validation has led to the appreciation of the need for a systems approach, as building scientists grapple with issues such as indoor air quality and sustainable buildings. We offer pre-design consulting to help eliminate future failures and defects.

The significant thing to remember about inadequate building performance is that it results in the vast majority of litigation, and the application of building science via the systems approach is among the more effective preventive measures against failures and defects. It is also a highly useful diagnostic tool when assessing the condition of existing buildings that are candidates for restoration and retrofit. In order to deploy the systems approach in the design and assessment of buildings, it is first necessary to establish a framework of performance requirements. Our building envelope experts can help with that.

RELATIONSHIP BETWEEN PHYSICS, MATERIALS, COMPONENTS, AND SYSTEMS

Performance concepts in building codes and standards have existed largely as constraints guiding the prescriptive codes and standards development process. One of the major challenges in developing an effective building performance objectives framework has been the establishment of explicit parameters supported by building science knowledge and specialized knowledge from allied disciplines. These are premised on the relationship between physical phenomena and building system behavior.

A building is a system that consists of materials, components (assemblies, equipment), sub-systems, and systems that interact with physical phenomena in the process of providing an intended level of performance to its immediate occupants and societal stakeholders.

Due to the multi-functional nature of components and sub-systems (e.g., a wall may provide structural support, fire safety, and moderation of the environment), it is important to relate constituent elements of the building to a coherent hierarchy of objectives. The hierarchy of physics, materials, components, and systems is a practical means of dealing with performance objectives at the conceptual level, recognizing that it may bear little, if any, resemblance to the actual intellectual process (design). The importance of differentiating between representations of relationships, and the actual reasoning processes which make use of these representations, cannot be underestimated. When understanding how the design relates to the finished building, having a trustworthy building science consulting company on your side can be invaluable.

A CONCEPTUAL MODEL OF BUILDING BEHAVIOR

Building behavior (performance) is a highly complex, resultant phenomenon. It involves numerous simultaneous and sequential physical phenomena, and the response of the building as a system will vary depending on the nature and arrangement of the constituent elements. At present, a comprehensive, explicit model of building system behavior has not been developed but is assumed to exist in some implicit form among the collective of building industry experts. “Industry Best Practice” is often used for conceptualizing the behavior of a finished building.

BUILDING SYSTEM INTEGRATION

A common purpose of building science is to achieve building system integration, not by-trial-and-error over many generations of building precedents, but each and every time a building is being designed and built. This implies defining a level of performance and a means of assuring compliance, which a third-party construction management team like BES can help with.

Optimizing performance goes beyond compatibility between the structure, enclosure, interior, and services. It involves the assessment of economic, social, and environmental parameters so that performance targets are attained affordably within the skill capacity of the industry. This effectively means innovation may be defined as achieving better performance and higher quality at less cost over the life cycle of a building or facility.

Applied building science research has indicated the control of moisture in building enclosure design generally takes precedence over other control measures simply because so many of the requirements for the control of heat transfer, air leakage, and solar radiation are satisfied when all forms of moisture have been carefully considered. Energy efficiency is a primary goal of most developed nations, and this objective is not compromised by designing building enclosures to manage moisture.

The levels of thermal insulation needed to avoid interstitial condensation leading to durability problems are equal to or higher than those required to provide cost-effective levels of energy efficiency over the life cycle of a building.

A number of related resources are also dedicated to explaining how various performance objectives identified herein may be achieved, but for the purposes of understanding building science concepts, it is important to appreciate that the building enclosure, or envelope, is the primary environmental separator/moderator. It performs a passive role, unlike mechanical and electrical systems, that actively supplement the amount of heat, air, moisture, and daylight the enclosure is unable to provide. When all active systems fail, the building enclosure is the last line of defense between the indoors and the outdoors. High-performance building enclosures provide passive sustainability during extreme weather phenomena and natural disasters, and safely shelter their inhabitants.

SYNOPSIS

In summary of the ideas and relationships that have been presented, the following conclusions may be considered:

• Buildings are systems that must be appropriately integrated by designers to achieve defined levels of performance.
• Building science provides a disciplined means of dealing with the physical requirements of buildings that are completely compatible with the architectural design and building construction processes.
• Innovation in modern architecture relies on building science and the systems approach to ensure that building performance meets the expectations of building owners, inhabitants, and society.
• The context for building performance has more recently evolved to include issues of ecology and sustainable development. This expansion of performance parameters, coupled with increasing consumer expectations, has dramatically increased the complexity of buildings. Performance objectives frameworks and conceptual models have become necessary methodologies to assure all aspects of the integration of well-performing building systems have been carefully addressed.

It takes a lot more than bricks and mortar to create a structurally sound, high-performing building. The team at BES, your building envelope consulting company, can ensure nothing falls through the cracks. Reach out today for a consultation.

REFERENCES

1. Building Science for a Cold Climate, NRCC 39017 by Hutcheon, N. B. and Gus Handegord. Ottawa: 1983.
2. Fields of Research in Building Science (brochure) by Education Liaison Committee. Washington, DC: Building Research Institute, 1963.
3. 3 Definitions as found in: Hierarchy theory: a vision, vocabulary, and epistemology by Timothy F. H. Allen with Valerie Ahl, illustrated by Paula Lerner. New York: Columbia University Press, 1996.
4. Fundamental Considerations in the Design of Exterior Walls for Buildings, Technical Report No. 13, Division of Building Research by Hutcheon, N. B. Ottawa: National Research Council Canada, 1953.
5. Development of a Wall Performance Classification System by Kesik, T. and David De Rose. Toronto ON: CIB World Building Congress 2004, May 2–7, 2004.
6. Knowledge in the Form of Patterns and Neural Network Computing Knowledge Engineering, Volume I, Fundamentals by Pao, Y.H., H. Adeli (editor). New York: McGraw Hill, 1990.
7. A Knowledge Based Systems Approach to the Assessment of Building Performance Proceedings of the Second Canadian Conference on Computing in Civil Engineering, pp. 469-480 by Kesik, T. and K.A. Selby. Ottawa, Ontario: 1992.
8. Objective Based Codes: A New Approach for Canada by Canadian Commission on Building and Fire Codes. Ottawa: February 1996.
9. Towards Integration of Service Life and Asset Management Tools for Building Envelope Systems Proceedings of the Seventh Conference on Building Science and Technology, pp. 153-163 by Lacasse, M.A., D.J. Vanier, B.R. Kyle. Toronto: 1997.
10. Architectural Technology Up to the Scientific Revolution by Mark, Robert (editor). Cambridge, Massachusetts: MIT Press, 1993.