Thursday, May 22, 2008

Jargon: Ground Source Heat Pump

According to the International Ground Source Heat Pump Association a
"ground source heat pump (GSHP) is an electrically powered system that taps the stored energy of the greatest solar collector in existence: the earth. These systems use the earth's relatively constant temperature to provide heating, cooling, and hot water for homes and commercial buildings."
In Las Vegas for example, to cool a space a standard heat pump must take heat from the interior spaces and move it to a heat sink. The heat sink is typically the air outside, and the higher the temperature of the heat sink the more energy is required to operate the heat pump. With ground source heat pumps the heat sink is the cool earth starting about 5'-8' below grade. Other sources of heat sinks include domestic water, ground water, ponds or lakes, and even sewer systems. I can imagine a system that uses a pool as a heat sink thereby saving heating costs for the pool.

More often this would be achieved by drilling an array of dry wells into the site and installing closed loop piping (often copper) packed in a heat conductive slurry (often bentonite) connected back to the heat pump by a system of valves and pumps. In Geothermal Heat Pumps Provide Sustainable Alternative for Architects, Russell Boniface explains energy costs for heating and cooling can be reduced by 40-70% with a properly design GSHP system. While this provides significant savings to an owner it may still be difficult to justify added up front costs of the system. Lenders and commercial leases are just beginning to take into account these energy and operational savings when evaluating the cost of these systems.

(Image at right from

In their book Geothermal Heat Pumps, Oschner and Curtis provide an overview of design and installation of GSHPs. They demonstrate that GSHPs generate 20-25% of the CO2 of standard heat pumps and obtain their energy saving from a truly renewable and secure source. A properly designed GSHP system may actually provide construction cost savings by down sizing emergency power requirements of projects like data centers and medical facilities. So you can save costs by going green!

Keep in mind that the phrase used to identify this technology varies in different markets; Wik
ipedia redirects you to geothermal heat pump, some builders use geoexchange, and others geothermal exchange or simply gx. Also, as this technology is often new to many designers and contractors, so you should seek out experienced professionals for advice.

Additional resources: US Department of Energy, US EPA Energy Star, and Natural Resources Canada
Normally, you can find additional information at the Geothermal Heat Pump Consortium but as of this writing their website is down.

This article has also published in the June 2008 issue of the AIA Las Vegas Forum Newsletter.

Paul Cline, AIA is an architect and builder in Las Vegas, Nevada. He is a member of the Young Architects Forum Advisory Committee and writes on issues of community, sustainability, and innovation in design and construction.

Saturday, April 19, 2008

Hire a Professional: your Architect

When you are ready to get an architect started on your dream home who should you pick?

At the top of the list you will need to see examples of an architect's work and find yourself comfortable with their design point of view. In addition to that you'll want to find yourself liking them after an interview. You'll be spend a lot of time and money with them. Work hard to find the right firm. As architecture can be a significant percentage of a home's budget find a firm with consistent experience in residential design. They will be more efficient and responsive.

The more of your own goals that you have been able to flesh out the better you will be able to determine if the architect you are considering shares them.

I have significantly modified a section of the AIA's "You and Your Architect" below in order to focus on residential clients, and I have changed its meaning in places. Click on the link to see the original.

When you are contemplating building your own home, choosing the right architect is vital to a successful project. Some of the many questions about architect selection are addressed below:

Q. At what point in the process of building my dream home should I bring the architect into the picture?
A. As early as possible, however the intent of this website it to reduce the total cost of ownership to clients and I recommend you complete as much leg work as you can prior to engaging an architect. That said, architects can help you define your project in meaningful terms and focus your decision making. They may also do site studies, help secure planning and zoning approvals, help you work out financing, and perform a variety of other predesign services.

Q. How do I find suitable firms to contact?
A. Contact other homeowners who have built their homes with an architect and ask who they interviewed and ultimately selected. Ask who designed a home you admire or that seems especially appropriate. Many local chapters of the American Institute of Architects (AIA Las Vegas) maintain referral lists and are available to assist you in identifying architects who can help you. The AIA maintains the website Architect Finder to help to develop a list.

Q. How many firms should I interview?
A. Consider a brief interview of three to five firms-enough to see the range of possibilities, but not so many that an already tough decision will be further complicated. Narrow it down to two or three immediately and reapproach the ones you feel most confident about.
Interview architecture firms that you feel can do your project because of their expertise, experience and ability to bring a fresh look to your situation. Treat each firm fairly, offering, for example, equal time and equal access to your homesite.

Q. What information should I request from firms?
A. Ask to see projects the firm has designed that are similar in type and size to yours or that have addressed similar issues. Ask them to indicate how they will approach your project and who will be working on it (including consultants). Ask for the names of other owners you may contact. Consider asking for a design budget and a hourly rate sheet to better understand the financial commitment you'll be making. Keep in mind a budget is difficult to provide without detailed information.

Q. Why are formal interviews desirable?
A. An interview addresses one issue that can't be covered in brochures: the chemistry between the owner and the architecture firm. Interviews also allow the owner to learn how each firm plans to approach the project.

Q. What can I realistically expect to learn from an interview?
A. You can learn how the architect's team will approach your project. Ask how the architect will gather information, establish priorities and make decisions. Ask what the architect sees as the important issues for consideration in the project. Evaluate the firm's style, personality, priorities, and approach: are they compatible with yours?

Q. On what should I base my decision?
A. Personal confidence in the architect is paramount. Seek an appropriate balance among design ability, technical competence, professional service and cost. Once you've selected the best firm, enter into detailed negotiations regarding services and compensation. The AIA Contract Documents the industry standard-offer an excellent starting point.

Sunday, February 3, 2008

Read: The Slow Movement

This article, The Slow Life Picks Up Speed by Penelope Green in the New York Times really resonates with my reasons for writing The Year Before My Architect. This strong notion I have that it takes time and effort to make good decisions about how we want to live.

In the 1990s a Slow Food movement began in Italy. The precepts are simple and are intended to improve quality of life. As Green puts it, Slow Food asks people to "use local ingredients harvested and put together in a socially and environmentally responsible way." In the U.S. a similar campaign is often branded Local Food. By choosing your meals based on these principles it is anticipated that you will eat healthier, support crop biodiversity, your local economy, and participate more fully in your community.

The article links to John Brown's blog the Slow Home. Take a look at his blog. I hope that my blog might slow my readers just long enough to improve your quality of life.

Best Wishes,
Paul Cline, AIA

Sunday, January 27, 2008

Jargon: Frost Line

Frost line and frost line (Wikipedia)

I was listening to the radio program Living on Earth and heard about The Home Ground Project which collects evocative definitions in their series The Language of Landscape. I heard Eva Saulitis of Homer, Alaska define frostline in a wonderful way, new to me. [Listen here.] It prompted me to give you my definition as well.

In architecture and construction foundations are critical to the success of any project. In this context the frost line is the depth below the surface that the ground freezes. I understand that the term originates from visual inspection of groundwater wells. You could actually see frost down the walls of the well.

Knowing the depth of the frost line is important in foundation design because soils increase in volume when they freeze (just like that soda that exploded in the freezer). If the primary foundation elements are above the frost line your whole house will move with the freeze and thaw cycle. If it is too expensive to dig below the frost line your structural engineer can look into shallow foundations intended to work with the freeze thaw cycle. For practical purposes the local building code may set an official frost line based on the worst freeze in the past 99 years.

If you are interested in more definitions from Home Ground: Language for an American Landscape check out their website The Home Ground Project or listen to previous entries from Living on Earth.

Sunday, January 6, 2008

Research 03: The World Where We Live

The house, neighborhood, city, and region we pick all interact with other critical choices of how we want to live. Work opportunities, safety, transportation, access to services; these factors and others must be addressed when committing to make a community your home. What can we use to make the best decision?

Here are my suggestions.

Do your best to live in a neighborhood that demonstrates it values people. Be interested in how people in various roles might interact with you if you choose this or that community. Try and evaluate the limitations inherent in the neighborhood. Look out for transportation. Are there sidewalks? Bike paths? How far are things you need from your home? Think density. Can you buy groceries without getting in your car? Is there somewhere you could stand on a soapbox and speak your mind? If you succeed in finding a community that values people you will have neighbors who are friends and playmates for your children, opportunities to meet and know people, and more freedom to be yourself.

Monday, December 24, 2007

Read: Family Design - Flip Artists

I ran across this article at via Design Sponge and knew it should be shared.

These parents have a beautiful home with excellent furnishings and 6 kids. They've done a great job understanding their needs and aspirations and working towards them. It also looks like they had an ample budget to get there, which helps. What aspirations can you incorporate into your home?

"Flip Artists - A Manhattan couple with six kids under 9 discover that they have a sixth sense when it comes to real estate." Remember to click on the House Rules slide show to see the rest of the house.

Monday, March 12, 2007

Research 02: Make Something

Along the way lets put our creative juices to work. This activity comes from a classmate at Tulane and is similar to how I keep in touch with design trends, learn about new designers, and store up design ideas for later use.

  • Pick up a design magazine at the bookstore or newsstand. If you are feeling adventurous pick out one that you've never read before. I like Metropolis and Dwell, but look for something that will let you discover something new.
  • Comb through the pages and tear out any image that looks interesting to you. Create a pile of seed images to draw upon.
  • Now collage these images together to create a room. It could be any room, even one that doesn't make too much sense.

For those of you who have never done anything like this... a collage can be as simple as you want it to be. Just tape or glue the images adjacent to each other in order to create a composition the can communicate a message.

Let the message develop itself. Don't take it too seriously.

After you develop the collage give yourself a quick review. What do your selected images say about what you might want in your home? When you examine why you placed one image adjacent to another, what does this tell you about where these kinds of adjacencies can occur in your home.

Save the collage in your Design Stockpile.