Thursday, December 30, 2010
As we're wrapping up construction of 631 James Alexander Way, a number of tests for both ENERGY STAR and LEED certification are conducted. These tests help to verify that the house performs as designed, with the result being not only a more efficient home, but also a comfortable and healthy home as well.
This video shows a blower door test being conducted. The blower door simulates the effects of a 35 mile per hour wind on the home, and measures how much air leaks out of the house under this condition.
For a house this size, the maximum air leakage that is permissible under ENERGY STAR guidelines is about 2,200 CFM (cubic feet per minute). As the video shows, the actual leakage from this house was subsequently less. Although the video shows a rate of about 900 cfm, the official test result was just over 700 cfm (we later discovered that someone had cracked open a window during the video 'shoot'). Thus, the house is about three times as tight as ENERGY STAR requires, and as the technician states, about six times tighter than a "to code," non-ENERGY STAR home.
What does this mean to the homeowner? First, a tight home results in significantly greater energy efficiency and lower utility bills. Those who followed the construction and testing of our LEED certified home at 233 Catawba Avenue in Davidson will recall that utility bills are half of those of similar sized homes. Second, a more comfortable home. Some of the other tests that are conducted verify that the output from the HVAC system is properly distributed, and temperatures and pressures are balanced throughout the house. Thus, the chances of cold or hot spots in the home are greatly reduced.
LEED is your customer's assurance that a home has not only been designed to the highest standards, but also tested to verify compliance with those standards. Do not settle for less.
Wednesday, December 1, 2010
I spent several years of my youth in Tucson, AZ. Tucson averages about 10 inches of rain a year (compare that to 40 for Charlotte), and it is not uncommon to go weeks without rain, especially in the hottest summer months.
Plants adapt to this environment by having large root systems and few leaves, or in the case of cacti they store water in their fleshy pads. Animals adapt by basically staying out of the heat. The desert is alive with animals at night and in the early morning, but come high noon all of the critters have gone underground, literally.
Humans have adapted to this dry, hot climate by getting their rocks colored. Yes, you read that right. They color their rocks.
Now, many people who move to the desert try to bring their hometown with them. They plant lots of grass, irrigate it endlessly, and plant non-native trees that remind them of their home back East. This is why people who move to the desert to escape the allergies find their allergies worse than ever before.
But, there's another group of people who don't try to beat the heat, but rather join it. They plant native species like cacti and mesquite trees, and instead of grass their front yards are landscaped with pebbles. But, to trick you into thinking they have a verdant grass yard, every spring they get the pebbles painted green. It's really hard to tell the difference between a painted pebble and grass until you get within a half-mile.
In North Carolina we don't have the harsh conditions of the desert. Nonetheless, water is a precious resource, and one that must be conserved and managed just like we do with electricity. Not too many years ago we experienced the driest year in recorded history, with water restrictions, brown lawns, and dirty cars. We continue to create more people, but the water supply is relatively fixed. That is not a sustainable equation.
We use some simple yet effective approaches to conserving water on our LEED homes. Landscaping is comprised entirely of native plants that by definition don't require supplemental irrigation. Turf is limited to no more than 40% of the softscape, and we use a drought tolerant turf. To the extent we use irrigation systems, they are designed to be efficient and to only come on when needed (and not to come on in the middle of a downpour). Lots are tilled prior to planting so that rain will soak into the soil instead of running off of compacted clay.
Inside, we use low flow faucets, toilets and shower heads which conserve water but provide the same level of performance as standard fixtures. The design of the plumbing system is important too, with points earned if all of the fixtures are located within a certain distance of the hot water source.
There are more exotic things that can be done to save water, like diverting "gray" water from showers and sinks to be used to flush toilets, or collecting rainwater in a cistern to be used for irrigation. These approaches are not for everyone's budget or taste.
Our approach helps conserve water, which is one of our most precious resources. In turn the homeowner saves on their water bills. Equally important, a LEED home is also a nicely landscaped home. Check back in a month or so and I'll post some photos of the landscaping on the home we're presently building on James Alexander Way in downtown Davidson. I think you'll be impressed.
Wednesday, October 27, 2010
Last week I was giving a talk and tour of our first LEED-certified home to a group of Davidson College students. I was making the point that a green home can (and should) look like a 'normal' home, and I mentioned that I'd once seen a home built out of old tires by Dennis Weaver.
I quickly realized that at 19 or so years of age, these students were probably not familiar with Dennis Weaver. Any chance I'd had at seeming like one of them flew out the window with my generation-defining reference.
But, the point remains. A green built home should look like any other home (well, actually better). As you can see by the photo of our current LEED home, it's a lovely house, one that is attractive to most homebuyers. While homes built out of old tires or bales of straw are interesting, they aren't likely to take off in appreciable numbers any time soon.
Another point that I made while talking to the students is that in order for green building to have an impact, builders need to build homes that are affordable to most people. While it's great that there have been several demonstration projects built by well-to-do individuals and organizations, most people cannot afford a home with every green bell and whistle. All builders, from production builders to high-end custom builders need to incorporate green building into their homes.
Once we finish the landscaping on the house I'll write more about the exterior features of this home, and how they contribute to a healthier, more sustainable lifestyle. One item of note on this house is the siding. Made of fiber cement, the siding on this house will last for several decades due to its moisture and termite resistance. An added benefit is that there is significant recycle content in the product. Instead of going into landfills, materials are reused in the manufacture of the siding, benefiting the environment without any negative impact on quality or cost.
Monday, October 4, 2010
We just finished applying spray foam insulation to the green home we are building at 631 James Alexander Way in Davidson.
Spray foam insulation is the bomb! I remember saying that when I was interviewed by DavidsonNews.net about the first LEED-certified home we built (233 Catawba Avenue in Davidson). I got this sheepish expression on my face because I realized it sounded silly coming from a 46 year old.
But, spray foam insulation truly is the bomb. What makes it so special?
The house on Catawba was the first time I used spray foam insulation. Once it was applied, the house suddenly got quieter. And cooler, even though it was still the middle of summer. The homeowner noticed it too.
Inch for inch, spray foam (we use an open cell product called Icynene) is only marginally a better insulator than fiberglass batt insulation. The R-value (r-value being a measure of the insulating quality of a product) of spray foam is about 3.7 per inch, compared to about 3.1 per inch for fiberglass batt insulation.
What makes spray foam a superior product is that it also provides a tight air seal when it is applied. The product is applied in a thin layer, but it quickly expands to 100 times it's size. As the photo shows, spray foam complete fills the cavity in the framing. By contrast, fiberglass loosely fits into the wall, and air can easily pass through it. It's like being outside in the cold with the same jacket, but in the spray foam world there is no wind, and in the fiberglass world the wind is blowing at 30 mph. Obviously you're much more comfortable without the wind. A house insulated with spray foam is several times tighter than one with fiberglass batt insulation, and as a result it takes less energy to heat and cool the home.
Spray foam also makes it easier to insulate the underside of the roof deck, and thus to have a sealed and conditioned attic. In fact, fiberglass batts cannot be used for this application. A conditioned attic results in a much more efficient HVAC system since the ductwork and equipment that is typically found in the attic is within the conditioned envelope of the home. Instead of a typical attic where the air inside your ducts can warm up by 10 degrees by the time it gets to the room, in a conditioned attic there is no change in temperature as the cool air passes through the attic.
Another benefit of spray foam insulation is that kids love it! My two children like to take the scrap pieces of spray foam and beat each other over the head with them, and they always ask if they can eat it. It's probably better to eat than fiberglass but no, you can't eat it!
Wednesday, September 15, 2010
Framing is always one of the most enjoyable parts of building a house (right next to seeing the joy on a homeowner's face when they see their finished home, and almost as enjoyable as getting paid). This is when the rubber meets the road so to speak, when the lines of the blueprint are translated into actual walls and the floor plan comes to life.
Framing also plays an important role in the green building process. For the purposes of LEED certification, framing counts toward material efficiency, durability, energy efficiency, and environmentally friendly products. I'll discuss each one in turn.
As you might imagine, a significant amount of wood goes into the construction of a new home. As it turns out, too much wood. Even after accounting for waste (doing accurate take offs and minimizing scrap are also key elements of LEED), there is simply too much wood in a house.
Building codes and tradition have encouraged 16 inch on center framing. What this means is that the studs on a typical wall are spaced every 16 inches, as are roof rafters, ceiling joists, and floor joists.
Everyone wants a solid house, but why pay for something that is not needed? If done properly, 24" on center framing works just fine, and reduces the amount of lumber in a home by over a third. The truth is, 16 inch on center framing is often just an excuse for sloppy framing. If you do it right, 24" on center framing will result in the same strength and performance, and with significantly lower costs. In this LEED home, our roof rafters, ceiling joists and floor joists are all spaced 24" on center.
Framing plays a key role in durability. Hurricane clips are a good example. We install them on every rafter, and they provide significantly more resistance to wind than simple toe nailing, at a minimal cost. Making certain that the loads in the house, from the roof on down, are properly transferred to the foundation is another aspect of durability. It sounds obvious, but not everyone does it. We do.
For all of its great qualities, wood is not a great insulator. If you can take wood out of the thermal envelope of the home and add insulation the result will be a much more efficient home. We use advanced framing techniques such as two-stud corners and ladder blocking to do just that. Again, it's simple, but not everyone does it. LEED certification is your assurance that your house is both well-built and efficient.
Finally, framing plays a role in the use of environmentally preferable materials. Products such as I-joists and open web floor trusses utilize scrap wood and smaller trees relative to dimensional lumber, and they are more consistent and stronger. At John Marshall Custom Homes we use framing products from local sources as much as possible, and we insist that our wood products are certified as being produced using sustainable practices.
Come by our green home at 631 James Alexander Way in Davidson and see first hand how framing techniques result in a stronger, more efficient, and less costly home.
Thursday, August 19, 2010
Green building is about much more than the house itself. The location of the home is important, and using the home as a tool to educate the public about the benefits of green building is also critical.
The process by which a home is built also determines whether a home can be considered 'green.' Site management, erosion control and tree protection are some examples. Recycling is another, and the focus of this blog post.
Prior to making a commitment to building green homes, I typically looked at construction waste management from a cost perspective; ie I would use whatever approach resulted in the lowest cost. If I had a big lot to work with, I'd usually get a 30 cubic yard construction dumpster, and every trade would throw all of their trash in it, regardless of whether the waste might have a second life. As a bonus, neighbors would inevitably take advantage of this big, free (to them) trash container and throw in old furniture, bikes, and anything else left over from the yard sale.
LEED rewards builders who manage construction waste effectively. The first part of managing waste is to minimize waste. Order what you need, not more. Use scrap effectively. I remember on the first LEED-certified home we built I drew out a cutting plan on the floor for the drywall team. This plan showed where full pieces would be used, and if a full piece had to be cut, I even identified locations where each piece of scrap could be used. Granted, the hangars looked at me kind of funny, and we didn't get 100% of what I wanted, but we got part of the way there. We ended up with much less scrap than usual (drywall is a great story which I'll blog about later).
Inevitably, there will be waste. What LEED encourages you to do is to segregate your waste into streams that can be recycled, and those that cannot.
We use small construction dumpsters from Mercados Construction Cleanup of Huntersville. We dedicate one dumpster to scrap lumber that can be recycled (essentially non-treated lumber). Signs in English and Spanish identify this dumpster, and we review it with each trade.
In addition to lumber, we recycle cardboard, drywall, and plastic bottles. I found that on the first LEED-certified home we were able to recycle about 38% of our construction waste. What's more, because of our focus on waste management we actually spent less money in this area. To me, that's the beauty of green building: learning to do more with less.
Sunday, August 15, 2010
It's pretty basic building science that moisture is not a good thing. The combination of wood and water can lead to not only structural issues, but health problems as well.
Minimizing moisture is a key part of durability. The crawl space is only one part of the house where moisture is a concern, but it is the most obvious.
Since 2008 John Marshall Custom Homes has been installing sealed and conditioned crawl spaces on all of our new homes (except those on basement foundations, of course). While nothing is an absolute guarantee that a home will not be subjected to moisture, using sealed and conditioned crawl spaces greatly reduces the opportunities for moisture - and mold - to occur.
The photo above shows the foundation of a new home we are building at 631 James Alexander Way in Davidson, NC. The preliminary stages of the sealed and conditioned crawl space have been installed, including insulation around the foundation walls, and a vapor barrier on the ground and piers. The vapor barrier that is presently installed is a 6-mil temporary barrier which will be replaced by the final 20-mil vapor barrier towards the end of construction.
Later, the wood framing band that sits on top of the foundation walls will have spray foam insulation applied. This type of insulation provides not only insulating properties but also a tight seal against air infiltration. A conditioned air duct will also be run to the crawl space.
To constantly monitor the humidity levels in the crawl space, we will install a humidity sensor in the crawl space and put the display in a prominent location in the house. We also educate the homeowner about the importance of moisture control, and steps to take if the humidity in the crawl space is outside of a desired range.
We've built many homes with typical vented crawl spaces, and have not had issues with them. But, the sealed and conditioned crawl space provides many benefits, and at John Marshall Custom Homes we have decided they are well worth the investment.
Framing on this LEED-certified home starts on August 16. Please check back soon for further updates as the house starts to take shape.
Tuesday, August 3, 2010
Durability management is about as exciting as it sounds. I remember a few years ago I would always meet prospects on the front porch of a house and start to discuss all of the structural advantages of our homes. I could see their eyes glazing over with that 'just show me the damn kitchen!' look.
I've changed my approach a bit now. But, durability is still important. The shine of that lovely kitchen wears off quickly if you're always dealing with maintenance issues.
Part of the LEED for Homes certification process is to have a set of defined strategies to enhance the durability of the home, and to have a third party verify that those strategies have been implemented. Things like kick-out flashings, keeping the foundation at least a foot above grade, insulating all hot water lines, putting ice and water shield in roof valleys...they're not sexy, but they help a home not only outlast it's present owner, but a few generations after as well.
One of the premises of a green home is that they are less resource intensive than a standard home. If a house is built to last for 150 years, that obviously uses fewer resources than building a home that will only last 50 years.
Having remodeled several homes that were not constructed with green building standards, I can tell you that even after 10 or 15 years they start to require significant maintenance, and by the time they reach 50 they're about at the end of their useful life. I confident that with proper homeowner education (another part of the LEED process) and maintenance, our LEED certified homes will last 150 years if not more.
Today we poured the footings on our next LEED certified home. As the picture shows, we use steel reinforcing bar ("rebar") in our footings. This steel bar greatly strengthens the concrete footing which is the support for the home. The result is less settling, and greater stability over time.
One of the things I look forward to when I'm much older is going back to the homes I've built and seeing how they've stood the test of time. Undoubtedly they'll weather the years better than I. Although by that time I may be well past my prime, it will be gratifying to see that our homes are still going strong. Durability management is what will make it happen.
Tuesday, July 27, 2010
....is the hardest part. The plans for our latest LEED-certified home have been with Mecklenburg County's plan review department since July 15. They told me it would be ten days, and they were right (well, I guess it's now 11 days and no word yet). I understand that they've cut back staff in response to the downturn in construction, but I would think that with fewer plans to review the turnaround time would still be the normal five days.
While we wait, the planning continues. This should be one of the better planned out homes we've ever built.
Hopefully next week we'll have an update that construction is truly underway.
Sunday, July 18, 2010
I guess the 1970s were my formative years. Whereas the sixties seemed to be the decade of psychedelics and drugs, the seventies ushered in a greater concern for our natural environment.
I'm not saying that there weren't drugs and free love in the 70s, but I guess I eschewed those in favor of Euell Gibbons (who famously ate pine trees), GrapeNuts cereal, natural food classes, and John Denver.
Growing up in equal parts West Virginia and Tucson, AZ, I developed a love for natural places. West Virginia was deservedly described as 'Almost Heaven' (although the song was really written about Maryland, but that state didn't have the proper number of syllables), and Tucson's beautiful deserts are ringed by even more beautiful mountains.
John Denver's songs really seemed to capture the spirit of nature. From the aforementioned 'Take Me Home, Country Roads' to 'Rocky Mountain High' and 'Calypso' and many, many other great songs, his music spoke eloquently about the glories of the natural world. I became a huge fan, and have remained so through the years.
Several years ago I was watching an interview with John Denver that was part of a concert he did to benefit the World Wildlife Fund. In it, he said that the most frequent question he got as an environmentalist is how one person could hope to have an impact on the enormous issues facing the environment. His answer was that no one person can do it all, but if each person can do what they can do, together we can make a difference.
That interview was the beginning of our commitment to the ENERGY STAR program. All of our homes since then have been ENERGY STAR certified. As a builder, I feel this is a small contribution I can make towards a cleaner, healthier environment.
Green building is a natural extension of our commitment to ENERGY STAR. I don't pretend to be able to save the world, but I do think that building homes according to green building guidelines can make a difference, especially if more people see the benefits of green building and insist upon living in green-certified homes.
As for LeBron James, he's been a real disappointment the past couple of weeks. First, he left Cleveland, and how he's bought a $45 million home. Seriously. I just hope that home never sees any championship trophies.
Tuesday, July 13, 2010
Welcome to our blog, and to my very first post. I decided to create this blog as a way to track the construction of a 'green home' in Davidson, North Carolina.
We have a model home, and in it there is a banner that says "Davidson's Green Home Builder." Of the three houses pictured, two of them are painted yellow and the other green. My six year old daughter looked at that banner and said "Daddy, here's what I don't understand: you call yourself a green builder but most of your houses are yellow."
As recently as a couple of years ago, my knowledge of green building was at about the same level as my daughter. Having built a green home in 2009, I feel I have a pretty good understanding of the process, and would like to use this site to share the process with others. In the meantime, I hope to gain a better understanding of how to use blogspot!
So, now that you've found this blog, I hope you find it informative and perhaps even a bit entertaining. We're in the process of finalizing plans for our next LEED-certified home, so check back soon for updates.