Tuesday, November 30, 2010
As I mentioned last month, the LEED system falls short of usefulness, and the best rating should be in dollars. The DOE system is in dollars, all right, but they are unfortunately using savings, not cost. Home size and "average energy cost of a home without upgrades" needs to GO AWAY. Give us a standardized yearly energy cost for this house, period. It's much simpler, and ultimately much more useful for everyone.
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.
Monday, September 27, 2010
One recent post sums it up: High Performance Houses
They've nailed it, pure and simple. Contrast it to a subdivision that was nixed by Golden. Golden has no idea of what it really wants, but they had this feeling they didn't want this. Over time, they'll understand that they want 100k houses and neighborhoods.
Does anyone else besides me think Denver is ready for something similar to 100k? The biggest difference in the two markets is that Philly has thousands of low-cost vacant lots ripe for redevelopment. In Denver, a vacant lot in a good neighborhood doesn't exist, so scrapeoffs in lower tier neighborhoods may be necessary. Let's finish the infill process in Denver and scrape or renovate worn-out houses as required before we tear up irreplaceable open space in Golden.
Their list of innovations really covers every phase of the business, except maybe the use of realtors. Lots of folks thought realtors would become obsolete because of the internet, and it just hasn't happened, and doesn't look like it will happen. Postgreen (the 100k development company) however, has pre-sold a high percentage of their homes. This means that they haven't really needed the conventional realtor relationship.
Monday, August 30, 2010
The whole business model for Smart Grid in Colorado is strange because it's a monopoly trying to save it's customers money.
The PUC tries to regulate against Xcel ripping off their customers, but they have almost no directive to promote investment now if it saves money in the future. Add to that some customer resistance to smart metering because it is viewed as an invasion of privacy, and you get a difficult if not impossible implementation.
Why do we care so much about the Smart Grid? Because if TRUE electrical costs could be accurately accounted for and allocated, a residential solar photovoltaic system can be shown to be a better investment than it currently is. We are firm believers in the theory that many small investments in renewables and efficiency can make faster and more nimble improvements in the US's overall energy problems. Big ideas and large projects take much longer to implement, because they are big. The large amount of capital required slows down the process too much, even if the ROI is significantly better than small projects.
If your home-based PV system gives you a return of 5%-15% on your money, millions of homeowners will quickly enter the green energy market as investors. Even if they have zero cash, they can partner with a 3rd party such as SunRun to get a system installed.
We have lots of politically conservative friends who even think PV is a good investment.
Although we were hoping that the Smart Grid could reduce PV system size, PV system cost has been dropping steadily, so this good news takes the sting out of Xcel's big fumble.
Sunday, July 25, 2010
HD Online LED bulb This bulb is bright enough at 428 lumens, but a little pricey at $20. But it's by far the best value as all the other LED bulbs that are this bright will set you back $30-$70 each. And get this, it's guaranteed to last for 46 years (vs 7 for CFLs). Other important features are that it reaches full brightness immediately (unlike CFLs) and is dimmable (rare for CFLs).
I have decided to concentrate on standard medium base screw in bulbs, since they will fit the most economical and the most common fixtures.
Wednesday, July 21, 2010
Denver Post Ad for Clear Choice
Careful, service companies like this always try to upsell you on anything they can. Stick to your guns if price is the most important thing to you.
In order to get windows that qualify for the Energy Star rebate, expect to pay significantly more than the $185 shown in this ad. Even if that eats up the whole rebate, remember you should save money every month because you will have a better window that loses less heat.
Wednesday, June 9, 2010
Thursday, May 20, 2010
I've built two homes with SIPs. Things didn't go quite as well as I envisioned, so I've been planning to try a double stud wall (not staggered stud) on the next project. My personal lessons learned to this point follow the same arc that Postgreen Homes has documented really well.
There were still a couple of fussy details about double stud design that were bothering me:
1. In order to cover the exterior insulation around the foundation/basement wall, the outer stud has to be cantilevered out too far.
2. Building a double stud wall is too much like framing two walls, which implies double the framing cost.
Building Science Corp and Betsy Pettit, AIA, have come to the rescue in the latest issue of the Journal of Light Construction (JLC):
They're promoting, and have tested, an Advanced Framing wall sheathed with foam. The innovation is the method to support the siding, 1x3 furring strips are attached to the stud wall with 6" screws. This furring is easier, cheaper and better than another stud wall.
Sunday, May 16, 2010
Call and ask any company how much they charge for installed windows, they'll say, "let us send out someone to measure, and we'll give you a quote". Fair enough, but you've just committed to one hour with some likeable guy who doesn't value your time that much.
With Window World, just count your windows, then multiply by $250. That's awesome. Of course, they have some options, some of which you need in order to receive the 30% federal rebate. Note that they don't even care about the size. Some windows are bigger, and some smaller, they figure.
As good as they are, you may find confusion when it comes to that all important SHGC number I keep harping on. (Some other guys have started major harping as well )
It just doesn't matter that much. You need some affordable windows NOW that actually go up and down and close tightly. Your south windows are shaded by your neighbor's trees anyway.
So I say go with whatever you can afford.
Saturday, March 27, 2010
Tuesday, March 16, 2010
Denver Business Journal
Where does Denver need improvement? In a word, traffic.
As you know, Denver's light rail system is set to become one of the nation's most extensive. The planning for this goes back about 20 years, so kudos to everyone in the region who recognized the problem in time to make a dent. Portland is one of the few cities with better mass transit than us, and it's #1 on the list.
Portland re-legalized ADU's a long time ago, and Denver is doing the same this summer if the new zoning code is approved.
Traffic is mostly a peak-period problem, so improvements can be made without widening highways (again).
If you are looking for a personal solution to this problem, sell your house in the suburbs ASAP and move to a transit adjacent neighborhood before prices get too high. Other options include telecommuting, bike commuting, and getting up early or coming home late.
Car sharing is growing: http://www.occasionalcar.com/
This is a great private sector solution that is much cheaper than owning your own car. Occasional Car has grown from two cars to eight in just over a year.
If you already live in a walkable neighborhood, you should check out this math:
1. Sell your car and save $300-$2000/month
2. Clean up and rent out your garage for $100/month. (An idea not really allowed by the new zoning code)
3. Join Occasional Car for about $50/month.
You're ahead by at least $350/month!
Sunday, January 31, 2010
Also, here's a brand new DC minisplit heat pump that possibly could improve efficiencies.
Friday, January 22, 2010
ADU's have been identified as the most sustainable feature in the new code. Not only do they provide some urban housing that should get many cars off the streets, they are the perfect place to put active solar. Note that passive solar access is impossible to provide except on the south end of every block.
Draft 4 allows for the 2-story ADU's that are needed to get solar systems up and out of the shade. As usual, the buyer of solar needs to be aware of the neighbor's trees so that his new system won't be shaded.