Wednesday, October 27, 2010
Monday, October 18, 2010
According to this article the location is the MOST important factor in low energy homebuilding: "Households in downtown Chicago produce one-quarter the greenhouse gases of households in nearby suburban Kane County"
What if, all of a sudden, say, like, in 2011, "production" homebuilders stopped concentrating on tearing up farmer's fields and building new infrastructure for new housing, and started concentrating on rebuilding run-down neighborhoods closer to the city center?
Just possibly the biggest single step toward halting global warming.
As mentioned before, the trend has begun on vacant lots in Philadelphia. Philly has a strong enough economy to support infill like this. But we're not seeing much of this anywhere else in US. In the rust belt, where vacant lots are available, cities like Detroit are on life support. Job growth is really the only driver of new construction.
Denver has a little bit of job growth, and homebuyers are learning more about these issues everyday. One day in the near future, a young pregnant couple will contact a neighborhood redevelopment company in a neighborhood like Villa Park and not even think of taking a drive out to the Wheatlands , even though the prices are tempting.
Then the announcement came that our water rates may increase sharply , so I figured it was time for a post about water and a long-term experiment of mine.
For fun and profit, I invest in Denver real estate, so water costs and landscape maintenance costs are very important to me. Therefore in 2005 when we acquired a house with a dead front yard, we decided to till out the weeds, place down weed barrier, and cover it with mulch. For the whole front yard, this cost $450 including mulch, and took one day with two laborers. In recent years, free mulch from recycled trees has become common.
This simple project saves about $140/year in water, and $200/year for mowing and maintenance. This particular yard doesn't look nice, but there are no weeds at all:
A dirt yard doesn't look any good either, but you still have to mow the weeds that sprout it if you have a rainy spell, and you get a lot more mud tracked into the house:
We've also experimented with a few drought tolerant plants, and found cactus can be grown without a drip watering system. Pea gravel makes for a better play area and lasts longer, but it is more expensive than free mulch.
Tuesday, October 5, 2010
I've been watching from the sideline, stubbornly NOT going for LEED qualification. In building code terms, LEED is far too prescriptive and not performance oriented. Throw in "too complex for real customers" and too expensive, and what you have is nearly worthless.
Here's a solution I've been mulling:
1. Let the building departments adopt the 2009 energy code as they wish. Then STOP any code changes forever, except for safety items. The technology is still changing too fast to attempt to follow it with prescriptive code "improvements". Another reason for freezing the code is to prevent those pesky unintended consequences that aren't even discovered for 20 years. (see Solar Driven Moisture in Brick Veneer at BuildingScience.com)
2. Then let builders build as they see fit. Good ones will keep improving the sustainability of their product. (If you care enough to be reading this blog, you're probably one of the good ones)
3. Here's where we replace prescriptive with performance: You can't get any sort of LEEP (Leadership in Energy Efficiency Performance) rating PRIOR to building anything. To get a LEEP rating, the home must have a simple Web-based monitoring device installed for at least one year. The cost of this should only be $1000-$3000, it only needs a handful of measurements, some of which are already there, like kwh consumption, water consumption, gas consumption. Add two indoor temperature readings, hot water tank inlet and outlet, outdoor temperature north side of house and south side of house, major appliance electricity consumption, etc.
This data can then be used to "normalize" the performance results. The square footage of the house is completely left out of the normalization calculations.
4. The LEEP rating is in dollars, the only unit that makes sense to everyone. (Just like a yellow EPA EnergyGuide label for appliances). A true net zero energy house gets a LEEP rating of $0/yr. If you put on excess PV panels, and the utility pays you for your excess production, then your LEEP rating can be calculated to equal what the utility pays you for the year, and is negative, say -$200/yr. A 1000 sq. ft. home built to 2009 code minimum might get a rating of $800/yr. A 2000 sq. ft. home built to 2009 code minimum should perform a little better per sq. ft. than the 1000sq.ft. home, so it might get a rating of $1400/yr.
This performance rating will always guide the builder in the right direction.
5. The other non-energy efficiency related metrics can have their own rating, such as LEEPdurability, and LEEPwater. A near-zero maintenance house might have a LEEPdurability rating of $30 per year, while a house that needs painting and new light bulbs often would be rated at $300/yr. Again, the LEEPwater rating is in $/yr. Oh yeah, don't forget LEEPembodiedenergy. That could be in kwh.
The ratings are thus understandable, simple, standardized, and allow the builder his own solutions rather than any suggested by LEED.
Eventually these ratings will be meaningful to buyers, and that's when the builders learn they must generate good ratings. That's what I like, market forces in play instead of federal policy!
Since this is so similar to the appliance rating program, the LEED officials must have studied the method, but I can't figure out why they rejected it.