Green Building

The Importance of Building Science

August 29, 2018

If you’ve been on our website or read about Deltec, chances are you’ve seen a thing or two about green building, or about its components: energy efficiency, air quality, material sustainability or building durability.  But have you heard about an umbrella term that encompasses many of these topics, the interdisciplinary study of building science?

As our green building and sustainability manager, with an academic background in physics, I consider myself a building scientist above all, and I’ve just returned from Building Science Summer Camp, an annual, highly sought-after conference put on by the Building Science Corporation, bursting with new insights and enthusiasm on the subject.

What is Building Science?

Building science is simply applying what we know about physics and other sciences to buildings, with a focus on moisture and heat.  As such, building science touches on concepts from material science:  the engineering discipline that studies the physical and chemical properties of materials (e.g. brick, plywood, insulation, drywall, anything buildings are made out of that might interact with moisture and heat in ways that may need to be considered), thermodynamics:  dealing with methods of heat transfer, phase changes, pressure dynamics, and mechanical engineering:  which gets into all the nitty-gritty of airflows and motors and equipment that generates heat, cools air, or produces or removes moisture, and even touches some on health and biology with respect to indoor air quality and mold growth (a natural consequence of moisture.)  And it’s pretty helpful to mix that in with a dose of construction management:  the common and necessary techniques of construction, how jobs are sequenced, and the best places in the construction process to do what with what material.

Why is Building Science Important?

Buildings use a lot of energy, and energy use has concerning environmental and economic impacts.  The biggest component of energy use in most residential buildings is heating and cooling.  Meanwhile, moisture in buildings can have huge impacts on the durability of building materials and on human health. Moisture and heat are often tied together in today’s buildings, due to physics, and due to mechanical systems which can be a way to remove moisture, or can sometime fail to adequately do so.

Additionally, while some problems with buildings would become obvious very quickly: (e.g., if the structure isn’t engineered right, gravity will pull it down, or if the electrical isn’t done right, you might have a fire), the discipline of building science often focuses on more insidious problems that might take time to develop. Things like high energy use due to hidden holes and drafts in a building, or moisture that builds up in a ceiling over time due to small defects in flashing.

Most of this is not about discovering new physics…we are typically just applying concepts we already know in ways unique to the particular materials and climatic conditions of a given building.  But it turns out there are many, many variables to the same old science, especially as new building materials are now proliferating, and have the potential to be used together in a nearly infinite number of ways in a wide variety of environmental conditions.  Without an understanding of building science, one might use a building technique meant for one climate that causes serious problems in a different climate, or pair together materials with vastly different moisture properties and end up with  unintended moisture buildup hidden inside a wall or ceiling.

Building science is often applied to new construction, but it is critically important for renovating existing buildings as well. Not only must the properties of currently available building materials be understood, but also how they might interact with historic materials.  How were buildings built 10, 50, 100, 500+ years ago?  What factors contributed to their longevity that should not be altered now?  One of the most interesting talks I saw at this year’s Summer Camp was from PhD Physicist who works for the Historical Society of Britain, advising on what to do with buildings that can be thousands of years old to keep them in good shape.   She applies the concepts of physics every day to this real-life challenge.

So, what kind of science is happening these days with respect to buildings?

Studying the properties of materials, and common ways they might get layered in a typical building, is one of the biggest areas of ongoing research.  There are so many product manufacturers out there making all kinds of different building products.  For instance, sidings made from coal ash, composite wood, concrete, or a mix of all it; insulation made from plastic, recycled blue jeans, or spun volcanic rock fibers. There’s a big focus on questions like:

  • What material properties are needed in what parts of a building?
  • How does this differ by what climate you are building in? Spoiler alert, this is a HUGE factor. Construction techniques are not the same in all climates.
  • What materials mixed together will cause unintended problems with high energy use,, moisture, fungal decay, or other durability issues?

When new materials come out, they must be tested.  The best practices for their use must be determined.  That information must be got out to the professionals in the world making decisions: builders, architects, sub-contractors, homeowners going out to Lowes and buying products for their home-improvement projects.

Indoor air quality is another big area.  This is an important study because homes are getting tighter, we spend more times indoors, and we put more materials into our homes that may contain all kinds of chemicals, which could offgas contaminants.  In regards to indoor air quality, there’s a focus on questions like:

  • What levels of what kinds of contaminants affect human health? Productivity?  Happiness?  Sleep and cognitive function?
  • What strategies for ventilating, diluting, or removing these contaminants are effective?  Cost-effective?

There’s lots of new developments in more advanced mechanical systems:  multi-stage heat pumps, mini-splits, fresh air ventilation systems, all kinds of incremental improvements in efficiency or other factors to existing technology for heating and cooling, water heating, (and dehumidification.)  What problems do newer systems solve—and what new ones might they create?  How do these systems work especially within exceptionally well-insulated, air-tight (commonly called “high performance”) homes (like Deltecs!)

Lastly, building energy use.  What saves energy, by how much?  In a single house, in a neighborhood, in an entire community or city?  Which energy saving measures are cost-effective, and which yield little results?  How should state and utility programs whose goals are to drastically reduce energy use, focus their program efforts?

Truly, there are many fascinating questions that remain about the buildings we construct and live in every day.

Where can I go to for more information on building science?

Building science is increasingly being taught in community colleges, colleges and universities, but most people who have been in the industry came here from somewhere else. Perhaps from construction in general (because you see the problems), or architecture, commonly mechanical or other engineering disciplines, and there’s a handful of us physicists in there too.

As a scientist working in green building, I do think it is critically important that when in pursuit of greener goals, we act on scientifically-backed information to get there.  Otherwise we are doing our clients, and the environment, a disservice.  So what are the sources for accurate building science information?  When I consult with green building clients, these are some of the most common sources I use:

  • Building Science Corp:  A consulting firm that does building science research, publishes great digests, and is who often gets called to deal with big moisture problems in buildings.
  • Home Innovation Research Labs: They do lots of research on products, and maintain a green building certification program, the National Green Building Standard.
  • Following a green building standard while building your home  is a great way to ensure that you’re incorporating the best building science practices into your new construction project.
  • US Department of Energy Building America Solutions Center:   The Building America Program is designed to funnel research funding to projects that improve building science knowledge, and the Solutions Center disseminates information to builders, architects, and contractors on building science.
  • Construction Instruction:  A smartphone app with lots of videos, details, and instruction manuals on energy efficient and durable construction techniques.
  • Green Building Advisor:  A web resource for green building aimed at builders and technical minded homeowners.  A word of caution: construction techniques and concerns relevant to cold climates somewhat overrepresented here.
  • Building Green (Formerly Environmental Building News):  Another great digest especially for material sustainability and environmental health perspectives.
  • Your Local HERS Rater:  The Home Energy Rating (HERS) Index is a useful tool for comparing home energy efficiency, and HERS Raters have in-depth training- on building science.  Consider hiring one to do a HERS rating on your new home project.
  • Your Local BPI Analyst:  The Building Performance Institute offers training for energy auditors and home performance contractors–the people who come in and upgrade your insulation or HVAC systems in existing homes.  BPI analysts are also trained in the causes of common indoor air quality concerns in new and existing homes, and have the tools to do some diagnostic tests.
-Leigha Dickens, Green Building and Sustainability Manager,   Building Science Manager at Deltec Homes

This blog is also posted on GreenBuilt.org

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