Tuesday, November 30, 2010

DOE Proposes "Home Energy Score"

The recently released DOE proposal for home energy ratings is getting closer to what's needed.

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

Should We Regulate the Size of Homes Because Big Ones Aren't Sustainable?

This debate is really simpler than it seems. Dollars are the units with which we can measure and compare everything in a home’s cost. The home uses more land? That equals more dollars in purchase price, property tax, storm runoff fees, etc. It uses more resources to build because it’s bigger? Well, it costs more. The only thing that can improve the accuracy of dollars is a carbon tax that is allocated and implemented perfectly. I realize that won’t be easy.
Recurring costs are a little more difficult. That’s why the EPA created a standard MPG rating for cars, and the Energy Guide rating for major appliances. With them, people could compare their future costs of operation of their purchase against the other competitive products.
I submit that the only worthwhile rating system for homes will be in dollars per year. An accurate HERS score can be converted to $/yr with a standard set of conditions.
Another significant metric for a house is the cost of transportation incurred by the residents. Walk scores and other ratings can be standardized and converted to $/yr, and reported on the MLS. This is already starting to happen.
Now, with a purchase price and a $/yr rating in hand, the consumer will be motivated to buy small, because it’s cheaper. If they can still afford a 3,000sq.ft. house, they should be able to buy it, there is no reason to put an artificial cap on size. Markets forces work well if the consumer is educated.
Unfortunately, LEED scores and Energy Star ratings are a confusing mess: http://greenbuildingindenver.blogspot.com/2010/10/leed-for-homes-rating-system.html

Monday, October 18, 2010

The Location of Your Low Energy House

Well it's the Denver area, yes, but what makes a low energy location?

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.

Stay tuned.

Water Conservation in Denver

I've not posted any prior recommendations about water usage, primarily because I'm an energy engineer, not a water engineer.  However, I was reading something the other day that said Denver's water usually beats out bottled water in taste tests.  Elsewhere, I read that 60% of our water usage is for landscaping.  WOW.  We residents are thoughtlessly spraying the best drinking water in the WORLD on our lawns.

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.

History Lesson:
During the drought of 2003, Denver Water (DW) begged us to reduce water usage, and invoked  watering restrictions that we followed successfully enough to reduce overall usage by over 40%.   DW promptly rewarded our diligent efforts with a sharp rate increase.   See, when the number of gallons of usage goes down, the infrastructure and management costs of water distribution must go up on a per gallon basis.   Gee thanks, DW.

Tuesday, October 5, 2010

The LEED For Homes Rating System

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

The 100k House in Philadelphia

I've been a fan of the 100k house website for almost 3 years. Chad Ludeman has created an innovative home building and marketing business model, an accomplishment that no large builder in America could ever do.

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

Smart Grid City Update

Well, unfortunately, Xcel and the PUC have really bungled the potentially exciting deployment of the Smart Grid City prototype in Boulder.

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

The Latest on Practical LED Lighting

Product availability is really changing fast. Last fall's offerings at Sam's Club and Costco no longer exist. So if you need LED lighting right now, the optimum solution is at Home Depot, "while suppplies last":
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

Competition for Window World

Apparently another company is trying to compete head-to-head against Window World:
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

Window Retrofit Redux

In this post, I'm speaking as a home rehabber only. The window solution for the actual homeowner who lives in their home could be different.

I fix homes to resell. The windows must look really good and work perfectly. Thermal performance isn't that important, but most buyers will pay a little more for double glazed windows. If there are some windows that don't open and close, the home inspector will find it. Then the buyer will probably ask you to fix it, or at least give a credit of about $200 per window.

The homes I fix average about 70 years old. They either have the original wood windows or vinyl replacement windows. 90% of the original wood single hung windows work BADLY. If the vinyl windows are over 10 years old, yes, there is some maintenance and parts replacement required. This work costs about $50 per window.

The rehabilitation of the original wood window with about 10 layers of paint on it will cost about $200, and it won't be as tight as a new vinyl window. It will also still be a single glazed non low-e window that tends to cause some thermal comfort problems in that room.

You can add storms to the inside or outside, but 90% of those are lost or inoperable after 20 years. With thoughtless tenants, this can drop to one year. Cost is irrelevant here, because they don't hold up long term.

I have tried all these different scenarios, and new windows are really the only option. When the home is to be resold, it unfortunately turns out that the cheapest window is the most cost-effective. Consumer education may eventually change this. In some munincipalities, the home must be updated to the new energy code whenever it changes hands. That also solves the problem but adds the other problem of forcing the new price of the house to be much higher, or cause the rehabber's margin to be slimmer. Too much government meddling, IMO.

I was particularly disappointed in the wood window restoration route. Yes, the windows worked again, but they still looked BAD. They were simply too far gone for restoration, and that's the case in 80% of the homes I rehab.

In summary, the window must operate, the payback period is irrelevant. $250 each for new windows is worth it, but I don't spend more than that on my rehabs since it would be wasted.

In the Denver area, another great company for replacements is Gravina. They offer a triple pane window that won't break the bank.

Thursday, May 20, 2010

Walls for New Construction, State of the Art from Betsy Pettit

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

Buying New and Retrofit Windows in Denver

You really only need to know two words on this topic: Window World

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.

No Posts in April

Global warming has obviously been cured in Denver. So I was skiing a lot, and not worrying too much about saving the planet.

Saturday, March 27, 2010

More on Low e "Solar" Windows

If you've been following along, you may have learned how important it is to have high a SGHC rating on your south facing windows in a passive solar house. I have also complained about how clueless American window manufacturers are on the subject.

All that is still true, but Martin Holladay of the GreenBuildingAdvisor has compiled a helpful list of the Canadian suppliers that understand the issue. Even though Home Depot may not have these windows, you should be able to get them shipped to you. Fiberglass frames and triple glazing also add value to your project, and are usually worth the extra money. Fiberglass ensures you won't need to replace them in your lifetime. Triple glazing not only reduces heat loss all the time, it prevents most condensation problems even when you live in Denver and crank up the humidifier when it's zero degrees outside.

Tuesday, March 16, 2010

Denver No. 7 on ‘Green-Cities’ List

A pretty good showing on another one of those "green lists".

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

Heat Pump Progress and More Options

Here's a heat pump water heater that can be placed in a different place than the water storage tank. That might fix the awkwardness of most HPWH applications. A garage, unused basement room, greenhouse, or even outside might make sense.

Also, here's a brand new DC minisplit heat pump that possibly could improve efficiencies.

Friday, January 22, 2010

Zoning Code Update

"Final Release" of Denver's new zoning code has now been posted:

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.