We passed the LEED AP Exam!

LeedLogos

It's been a little quiet here on the blog as we've been busy studying.

LEED for Homes was still in the pilot testing while we were building our house, however we did make a significant effort to make the best of site orientation and use green materials wherever we could.  To familiarize ourselves with more of the details of LEED, we decided to pursue accreditation.  Now we are officially accredited professionals! 

During the design process we relied on a few good internet resources for viable green products and systems.  One of the best is Building Green (the publishers of the excellent Environmental Building News).

Air Conditioning

We broke down and asked Bob to go ahead and put in a conventional air conditioner last week.  The house was doing very well considering the heat wave we’ve had, but when the temp climbs over 95 degrees for over two weeks straight, and topping out at 100, it gets uncomfortable!

Fortunately, we had budgeted a high-efficiency DX cooling unit, and Bob has worked installation into his schedule.  If we get our photovoltaic panel array at some point, I guess we can feel a little better about using the energy for powering this thing.

At 90 degrees and under, the combination of good cross ventilation and ceiling fans in every room is fine, so most of our summer we will be leaving it off.  I’m not a fan of conventional air conditioning, because in my experience, it results in closed up buildings where no one interacts with the outdoors.  With our indoor/outdoor patios, we will see if we can keep a good balance...    

Tankless Water Heater

Mike has most of the plumbing completed.  Over this past weekend he roughed in the tankless water heater.  It’s a large(r) capacity Rinnai tankless (or On Demand) gas powered water heater. 

We are excited to see what kind of energy savings a unit like this can provide for us.  Per the Energy Star label this unit uses 183 therms per year.  Our current conventional water heater uses 258!

Furnace

Bob put in our furnace last week.  We spent some time analyzing the heating and cooling loads to size the unit properly.  Considering we have very well insulated walls and roof, plus triple pane glazing, the unit can be smaller than typically used for a house of 2500 square feet.

This is a Trane 95% high-efficiency unit with a two stage variable speed fan, so we hope to see some significant savings on energy usage (especially when combined with our tankless water heater).

Note:  Again, we see this as the next best thing to radiant floors which were out of our price range.

Windows & Doors - Loewen it is

We were interested in finding windows/doors which were high quality and energy efficient, as well as having a modern look with wood interior/exterior clad. Out of all the options we researched and priced over the past year, it came down to Kolbe & Kolbe, and Loewen.  Both of these window manufacturers make an excellent mid to upper grade window, with Loewen perhaps slightly more refined.  Loewen was a few thousand dollars more overall, but we are fairly certain the quality and finish will be worth it.

Loewen comes standard with a nice vertical grain fir interior and to top it off, we got triple pane glass on the big openings!  It will not help much with solar heat gain, but the insulating value with the Heat Smart Plus System 3 (Loewen’s name for triple pane glazing) is much higher than a base double glazed window or door.

It would have been nice to have the big exterior folding or sliding door packs for the back and front patio, but it seems that they are still out of reach for our budget.

Mechanical Ideas

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Since we had to forgo the radiant floor system, we’ve had to get serious about what we will be using for a forced-air mechanical system. We will be using a high-efficiency furnace (90% or better). Instead of using the “rule of thumb” type sizing, the more thorough “right sizing” or “Manual J” method will be used. In addition, we will hopefully add third party testing - blower door and duct leakage.

We are still on the fence about using the traditional compressor-based air conditioning unit (granted it would be high-efficiency - 15 SEER) or go for an efficient indirect swamp cooler. The trouble is we haven’t found a cost efficient method for combining these two very different systems.

For domestic hot water, we will be using a gas fired tankless water heater (on-demand). I think we will start with just one for the entire house, and probably rough-in for a second, considering we are also prepping for a future guest suite on the basement level.

SIPs

We will be using SIPs (Structural Insulated Panels) for the exterior and roof of the house. Although the cost is a bit more than conventional framing and cellulose insulation, the benefits are numerous: Increased insulating value with foam, straight and plumb walls (presumably), and reduced waste. Unfortunately, however, you cannot use recessed cans in the roof panels at the 2nd floor level, so we’ll make some adjustments to the original lighting scheme.

Note: For information on SIPs, visit www.sips.org

Interior Lighting Studies

We are now beginning to look at interior lighting schemes.  The challenge is to move beyond a sea of recessed “can” or track lights and arrive at something a bit more interesting at a reasonable price. In the quest to control energy consumption, the wisest choice would be compact fluorescent fixtures.  However, we are still having a hard time getting over their start-up behavior, light color, color rendering, and a “lack of brightness”.

There are trade-offs to think of with can light sizes too:  six inch and up are readily available and cheap.  Most smaller sizes, which are nicer and more subtle are more expensive, have limited wattage, and require more fixtures. Although low voltage would be a choice to get smaller fixtures with bright lights, we want to avoid both the cost as well as the sparkle and glare that they give off.

For more images, check out our renderings on Flickr

Boulder Solar Home Tour

Boulder is known for it’s tenacious commitment to sustainability at all levels. From government all the way down to the single family house, recycling, energy conservation, etc. is paramount. We were excited when the flyer came via e-mail that they hold a solar and green home tour each year. However, after asking around, we were forewarned that even though the technologies used might be highly advanced, we should not count on any great modern design being a part of it! Luckily, the first house we hit was done by a cool Boulder Firm called Vast. Using SIPS and a solar water panel heating system combined with great space layout and design, this kept us intrigued for the better part of an hour. The other three houses were “design challenged” and not particularly inspirational.

Boulder Solar and Green Home Tour Site: Center for Resource Conservation