Can We Design Buildings for Heat and Cooling that Mimic the Human Body

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

I spend lots of time thinking about buildings. Sad; I know. Lately I have been wondering how we wound up in such a confusing state. It’s like looking under your car hood. Have you looked under your hood lately? It looks like a building design. Who in their right mind would have started out to design such a complicated mess? No wonder we need so many building scientists and we pay a hundred bucks an hour to get our cars fixed. Can we step back for a minute?

Thermal comfort in the built environment needn’t be so complicated. If we could start from scratch and try to make buildings comfortable based upon our own organic experience, what would we do? I live in Philadelphia.  If I go outside in the winter and try to passively stay comfortable – passively meaning to not use any outside energy sources – I would use lots of layers of clothing, would zip up tight and cover my skin.

Coincidentally that is what we require in our cold climate building codes.  Lots of layers of clothing means R-value. When you wear lots of layers of clothing you are trapping gas inside layers.  The gas is the insulation – gas gives you resistance to conductive energy heat flow – that’s R-value.  So when you are wearing lots of layers you are wearing R-value. When we say zip up – that’s getting air tight. We finally woke up and added that one to the cold and mixed climate codes as well.

The problem comes in the summertime. To stay cool, you would take off those layers, wear light colors and try to get air flow around you.  You would wear airy fabrics to release as much heat from your body as possible and light colors which don’t get hot in the sun. If you were stuck wearing lots of layers and were zipped up tight, you would have to blow cold fresh air into that outfit to stay comfortable. Our goal should be not to do that. Remember, passive technologies rule and active technologies cost $$$.

We need to find ways to help a building be warm in the winter and stay cool to begin with in the summer. I am looking for changes to our practices that will enable us to do to buildings what we do to ourselves. How would you build your building differently?

If you can’t strip off all the layers of clothing the very least you will do is unzip so can we figure out a way to unzip our buildings? I know we want to be air tight in the winter but can we figure out a way to use air to remove surface heat in the summer? I think ventilated claddings may be one answer.

Can you think of some others? To go back to the car analogy, let’s stop bolting more stuff onto the internal combustion engine to make it more efficient and drop in an electric motor. It needn’t be so complicated.

Off-Site Manufacturing Could Play a Larger Part in the Building Renaissance

Danny Small

Danny Small

Danny Small is Manager, Building Science Development for CertainTeed Corporation

Lately I’ve been revisiting the benefits of modular or prefabricated home construction, otherwise known as off-site manufacturing (“OSM”). There are several advantages to this method of construction that could be attractive to consumers looking to build a custom home.

This isn’t your daddy’s mobile home we’re talking about here.  The traditional manufactured (“mobile “) home is built to special Housing and Urban Development (HUD) building codes.  These homes are extremely simple, lower-end homes constructed in one or two pieces on a steel frame.

Today’s modular home can be beautiful, complex, exquisitely detailed and of the highest quality.  It’s built in modules or panels, in a clean, climate-controlled facility to meet (and often exceed) standard building codes for the area where the home will be finished.   The modules or panels are then shipped to the construction site, where they are permanently assembled on a full foundation, and the final details are finished.  Once completed, these homes are indistinguishable from site-built homes.  For some examples, check out Haven Custom Homes’ gallery.

While off-site construction has been around for decades, most of the earlier homes fell into that category of mobile (HUD-code) homes.  However, the move toward more sustainable, energy-efficient, healthy homes creates compelling reasons to look at modular as a truly viable method for all construction.

Some of the advantages of offsite construction are:

  • Construction can begin while foundation work is done, reducing the overall build time by several weeks.
  • Because building is done indoors in a climate-controlled facility, there are no weather delays.  Crews can work year round with no problem.
  • The home is built dry and clean because the wood is not subjected to dampness or dirt.  This could make for a healthier house.
  • Greater accuracy in cutting is possible because precision equipment can be utilized.
  • Lower costs because of consistency with crews and minimal lost time.  An off-site built home can cost up to 15-20 percent less than the same home built on-site. (Source: NAHB)  Savings for commercial construction can be much higher.
  • Very low waste.  Just about all remnants can be re-used for other projects.  This enables contractors to purchase more wisely.
  • Off-site manufacturers can ship up to 500 miles from their factory.
  • The building envelope is fully customizable, enabling increased energy efficiency in the wall and ceiling systems, as well as design features that meet the needs of the occupants.
  • Modular building, especially in commercial, enables easy expansion to buildings when needed.

Although off-site construction currently accounts for only two percent of construction in the U.S., the industry is gaining popularity.  In Europe, especially countries like Sweden, this type of construction is on the rise and accounts for up to 40 percent of new construction. 

If you are considering building a new home, a vacation home or a small office, do a cost comparison for on-site versus off-site construction.  You may be surprised by what you find.

Sustainability Gaining Momentum for Government Managed Buildings

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

I recently had the pleasure of doing a presentation to the General Services Administration (GSA) region 3 office in Philadelphia.  I was invited by a GSA architect who had participated in a previous seminar I had conducted for the American Institute of Architects (AIA).  The presentation was also simulcast to other GSA offices as well as employees who were telecommuting.

What I was not aware of prior to my visit is that GSA in responsible for public buildings that are non-military, non-postal service or other organizations that control their own real estate around the county. Not only do they have continuing education requirements within their organization they have a strong emphasis on sustainability. That’s exactly what you want to hear from government.

GSA serves as the property managers for many of the buildings around us every day. Given that at least 90 percent of our building inventory needs to be upgraded for energy efficiency, it was reassuring to see that the folks who are responsible for government controlled public buildings are on board with sustainability and are staying on the leading edge of knowledge. I was especially pleased to learn that the emphasis of sustainability doesn’t simply stop at how a building is designed and constructed but goes all the way through the way the GSA operates and procures for these buildings.

It was great to see that the culture of GSA is entrenched in sustainability.  That, for me, sends a message that we are on the right track of a very long road toward significant improvements in reducing the carbon footprint of our building inventory.

Building Hope for the Future with Habitat for Humanity

We all know that homeownership is considered the cornerstone of the American dream.  But many of us take that dream for granted.  I was reminded of this when I attended the dedication and blessing of a home with Habitat for Humanity in Chester, Pennsylvania outside of Philadelphia.

As a corporate sponsor of what we have come to refer to as the “CertainTeed House” because of the many CertainTeed products incorporated into the building envelop of this two-family house, I participated in the dedication and blessing of the house.  The family, a single mother with two daughters who will occupy half of the house, seemed simultaneously overwhelmed and excited.

The group of family, friends, sponsors and supporters clustered into what would soon be the family’s living room as the Reverend began the dedication and blessing.  The group traveled from room to room with the family carrying a candle as each area was given a special blessing – from the kitchen where nourishment is prepared to the dining room where bread is broken and shared to the bedrooms where sleeping safe and secure is desired.  Once the blessing was completed, the keys were presented to the family marking the final transformation of this building from simply a house into a home.

It was beautiful!

But there was an added sense of pride that I felt standing in this completed house that would be the dream home for this family. Over ten weeks during the building of this house approximately 80 of my co-workers volunteered time on the site to help with the build.  The opportunity to gain hands-on experience with CertainTeed roofing shingles, housewrap, vinyl siding and railing, insulation and gypsum products was as valuable as the satisfaction of giving back to the community in this very special way.  In some cases it brought employees together whose paths would not cross at work and in other cases departmental teams used this as a teambuilding exercise.

In the end, it was a learning experience for all and a lesson in community that has no equal.

That New Car Smell Could Be Killing You Thanks to VOCs

 

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

If you follow organizations and companies dedicated to sustainable solutions such U.S. Green Building CouncilLeadership in Energy and Environmental Design (LEED) or even this Blog you have probably seen an increased discussion about VOCs or Volatile Organic Compounds.  But I am not sure that people, in general, are aware of how pervasive VOC’s are in our lives.

 By definition a Volatile Organic Compound is an organic material with a growing point less than 250° Fahrenheit. For most of us this means that these organic compounds tend to exist as gases.  They are in many products that we buy and they also can occur naturally.  They have a wide range of adverse health effects including eye and respiratory tract irritation, headaches, dizziness, visual disorders, and memory impairment in other words, they are not good for you!  Organizations such as the Environmental Protection Agency (EPA), Occupational Safety and Health Administration (OSHA) and Health Canada have clearly spelled out the effects of long-term exposure to elevated concentrations of VOCs.

Most people recognize the presence of VOCs by their smell.  They have a distinctively unnatural smell.  I always tell people if it smells bad it is bad.  We all have a genetic memory in our bodies that identify bad smells.

As I have mentioned in a previous blog about tightening the building envelop, VOCs are all around us. They are found in cleaning products we use, carpeting, paint, lacquers, printing products – there is an exhaustive list. 

When VOCs are part of interior air you only have three methods of reducing them: capture them, kill them off, or ventilate them away. In terms of capture ordinary particle filters do not work. Filters made of activated charcoal are good at capture but these filters don’t work at the high air speeds which occur within our HVAC systems. Emerging technologies, such as AirRenew® which we’ve spoken of before, provide a new means of sequestration which HVAC filters do not. To “kill them off” requires ultraviolet light (UV). Formaldehyde, for example, has a 14 day half life in the presence of UV but we don’t have much UV inside our buildings. This leaves ventilation as a functional option. Providing fresh air ventilation rates in accordance with ASHRAE 62.1 for commercial buildings and 62.2 for residential buildings is a good place to start.

Trust your olfactory system – if it doesn’t smell right you may have a build-up of volatile organic compounds!

When You Build it Tight You Have to Ventilate Right

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

If changes are made to an existing home in terms of tightening the building envelope and you see changes other than your utility bills going down, pay attention to the details because they may be a warning sign that you have not properly ventilated the home.

Lack of adequate ventilation in a home can result in serious problems.  The more obvious one that appears in obvious places is elevated humidity. If you are sweating the inside of new insulated glass windows in the winter when you didn’t before then your interior humidity has gone too high.  Another warning sign is dirt stripes appearing on the walls in front of the studs.  Musty odors, sweating or condensation, or unusual patterns on your walls could be indications of a ventilation problem.

However, moisture is not the only concern.  You also need to be concerned about gas concentrations in the air because of the dangers associated with them and the build up of volatile organic compounds (VOCs). VOCs are emitted from many products that exist around the home but if you tighten up a home and don’t provide adequate fresh air, they are now being trapped within the home.  Many volatile organic compounds breakdown with exposure to ultraviolet (UV) light outside the home – formaldehyde for example has a half-life of about 14 days – but inside the home UV light is diminished and so has little affect on the concentration of the VOCs. VOCs could be coming off of products which you would never suspect.  For example, some citric acid cleaners that smell like orange can have amazingly high VOC concentrations. Remember, what has changed in the equation is the amount of fresh air that had been there before that helped evacuate these things from the home. The standard furnace filters we employ do not filter out gasses – they filter particles.

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (AHRAE) has very specific guidelines on how much fresh air is needed for a healthy environment.  ASHRAE 62.1 references the calculations for commercial buildings and ASHRAE 62.2 is for residential buildings. It is critical to review these guidelines in order to properly ventilate the building envelope especially if you are making changes. When homes are tightened for energy efficiency you must make sure that adequate fresh air ventilation is taken into consideration.  There are many ways to do this that are compliant with the ASHRAE recommendations. And remember, if you find signs of moisture it’s like the canary keeling over in the coal mine.  Heed the warning!

YouthBuild Akron, Ohio Goes for LEED with CertainTeed

 

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

CertainTeed and our parent company Saint-Gobain have a three-year partnership with YouthBuild USA providing expertise and products for projects they are undertaking in various cities around the U.S.  Last week, I conducted some training programs for the YouthBuild organization in Akron, Ohio on the building envelope and how to select products to help them meet their LEED goals. YouthBuild helps train young adults in green building techniques and construction practices on hands-on projects in their community.

This project is a renovation of an existing home and based on the information from their design charrette, they may reach LEED Platinum which would be awesome not only for a low income housing project but as far as I can tell it is the first LEED H Platinum project in Akron.  The best part is that the house next to this home was previously rehabbed by YouthBuild and is nearly identical in layout so they should be able to do some comparisons of the energy savings.  Of course, results won’t be as “cut and dry” as we might like because you can’t control the behaviors of the occupants.  However, we should be able to get some relative comparisons as the homes are of identical size with identical orientations.

Based on the products and systems Akron YouthBuild are planning to use, they are hoping to renovate to a Home Energy Rating System (HERS) score of 65. This means that the home consumes 35 percent less energy than what is building code standard of 100.  This is a very aggressive score. HERS is a program of the Residential Energy Services Network and a registered HERS rater is working with them on this project.

While not all the products/systems have been selected, during our visit we made some suggestions especially for insulation, gypsum and roofing based on their goals and the building assembly to help with the EPP (Environmentally Preferable Products).  We were also able to add points because of the proximity of CertainTeed plants to the project location.

It is great to see these projects educating builders of the future in green and sustainable techniques. I also believe it sends the right message to the community in that a sustainable habitat is possible for everyone.

Sustainability on Display at Louisiana State University

 
 

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

I recently visited Louisiana State University to speak to the Baton Rouge Chapter of Construction Specification Institute (CSI). The sessions were held to assist the Chapter members earning Continuing Education Units for their professional credential renewals.

Steve Tubré who is the program chair for the chapter and Construction Contract Administrator and Director of Quality Assurance for Billes Partners, LLC in Baton Rouge invited me but I had no idea what a wonderful resource I would be introduced to while there.

LaHouse at LSU

LaHouse at LSU

The meeting was held in the LaHouse – Home and Landscape Resource Center which is part of the LSU Agricultural Center.  The house is a research-based showcase of solutions and an educational outreach program designed to help shape the future with homes that offer more comfort, durability, value, convenience, environmental quality, safety and better health with less energy, water, pollution, waste, damage and loss.

Throughout the house, the building envelope has cut-away sections to show the various different layers of construction which were employed in each different systems. Some examples of what you can see are the constituent layers of a stucco wall, and EIFS wall, and an insulated concrete form (ICF) wall.

What a wonderful way to illustrate the concepts of sustainable design and educate visitors about designs and systems to create the homes of the future. The LaHouse Resource Center provides a local and living showcase of solutions for sustainable homes and landscaping. The fact that it is part of the Ag Center and not the school of design was also intriguing.

The LSU Agricultural Center is in view of the football stadium so the next time you find yourself at a Tigers game swing by the LaHouse for some inspiration.

Designing Buildings with the Future in Mind

 

Glenn Jackson

Glenn Jackson

Glenn Jackson is Director, Corporate Marketing for CertainTeed Corporation

Part of the conversation regarding sustainable design is a move toward improving performance and addressing specific needs of the potential occupants of a particular space.

The building industry has historically designed buildings based only on the need to provide a place for people to live, or go to school or to heal when sick. 

Today, so much more is taken into consideration. Product manufacturers, the design community and even building owners are much more focused on asking “What problem are we trying to solve” or “What elements need to exist in a building to help address performance based criteria such as, learning, healing, innovating and working.

Creating unique spaces is becoming more the norm even within what we refer to as vertical markets or niche markets which meet the needs of a particular industry.  Standards for design or performance may exist within a vertical market such as educational facilities or healthcare facilities but each project will have specific needs driven by geographical and environmental conditions, uses for the spaces, aesthetics and building owner preferences.

Some of the areas most critical to building sustainable and performance-based structures are thermal and acoustical comfort which is not seen but does affect our physical comfort and wellbeing.  Visual comfort speaks to our need for natural light.  Innovations in glass products are revolutionizing the industry.  Indoor air quality is crucial in all buildings and systems, and products are available to address most concerns for creating clean indoor air.

In the end, the efforts made to design and build high-performance, sustainable, buildings with solution based systems will provide significant savings for the end users.

When it Comes to Air Tightness in Buildings – Don’t Forget the Garage

 
 

Lucas Hamilton

Lucas Hamilton is Manager, Building Science Applications for CertainTeed Corporation

Many of our houses have attached garages which are, for the most part, unconditioned space within our habitat.  It is the interface of these two spaces which so often fails in our attempts to conserve energy and have superior indoor air quality. 

For starters, you have to make sure that the garage is air sealed from the rest of the structure because of what you store in that space. You store things in your garage because you want them out of the weather but you don’t want them “indoors.” Very often negative pressure is generated in the home by exhaust fans and dryers. In your home’s attempt to reach a neutral pressure with the exterior, it will often pull air from the garage into the home.  Now all of the gaseous and particulate contamination which is associated with what you are storing and doing in your garage is coming into your home. Think about what is on the other side of these “interior” walls – typically they are the rooms where we spend the most of our waking hours; kitchen and family room. If the separation plane between these spaces is not made air-tight we might as well move into the garage.

One small detail which is best addressed during the time of construction is breaking the continuity of framing chases between the garage and the house typically found in the garage ceiling. As the second floor framing runs continuously across one of the garage interior walls, air-tight blocking needs to be installed between floor framing to close this avenue of air migration. This is obviously easier to achieve with dimensional floor framing or “TJI” (Trus Joist I) than it is with modern trusses. Also ensure that any doors leading from the garage to the living space are properly sealed and air tight. Get a new door sweep if the old one is worn out. One great indicator of an air leaky passage door is a dirt “shadow” in the carpet just inside the sweep. Carpet fibers make excellent air filters and atypical soiling patterns are great indicators of air flows.

Once you’ve decreased uncontrolled air flow between the home and the garage is there added value by adding an insulated exterior garage door?  Absolutely! Any way that you can tighten or insulate the envelop will improve the efficiency. When you are making any changes with regard to air tightness in the home don’t forget to include the garage in your decisions.