Friday, September 28, 2007

Chicago's Demand Management Scheme

I harp about utility demand management a lot. Take a look at what Chicago is doing in this field. With a properly designed system in Chicago, you might never have to pay more than $0.03/kwh. In Denver, you never can get a rate of less than about $0.08.

Technically, it doesn't save any energy or prevent CO2 generation. It does, however, eliminate the necessity of building of new, larger power plants. Reducing utility capital expenditures should help keep electric costs down.

In fact, it's the first on the list of sustainability priorities that electric utilities must pursue, listed here in order of best cost/benefit:

1. Peak load shaving (with nighttime load valley filling).
2. Conservation.
3. Bringing renewable energy sources on line.

Wednesday, September 12, 2007

Sustainability and Maintainability

Sustainable Housing can be defined as housing that conserves resources as much as possible.

What's the most important resource to the average person? Their MONEY. Therefore, new green built homes should not only aim for zero energy, but also for zero maintenance. Life's too short to paint siding.

Here's the start of my zero maintenance checklist:

1. No exposed, painted wood. Board and Batten wood siding may be used if you make the pledge to let it weather naturally, and turn silver grey, then mottled dark brown.

2. Use large gutters and downspouts. The bigger they are, the less likely they are to clog. Employ scuppers where appropriate, they can be cleaned in a fraction of the time. Pop rivets should be specified in lieu of screws. "Gutter Helmet" type devices are not the silver bullet, but they can help.

3. Consider designing the house to look good with galvanized sheet metal trim. 24 gauge galvanized gutters and fascia will never have to be replaced or even painted in your lifetime. When it does start to rust in 80 years, let it, and go for a rustic look. Failure is still 40 more years out. Of course, copper is even better, but the price/performance is not.

4. Pay a lot of attention to the "splash zone" where rain puts wet mud on the house on the lowest 12"-36"

5. Low maintenance landscaping. Please don't be tempted to put concrete and asphalt everywhere, or astroturf.

6. Fiberglass windows. These really are the only option for zero maintenance windows. Vinyl will crack eventually, and any sort of wood window needs regular painting or varnishing.

Sunday, September 9, 2007

Attic Design Update

The gurus at Building Science have updated their conditioned attic recommendations for every climate. If there is one code requirement that should be implemented immediately, this is it.

And for those roofers and shingle salesmen who always say "It will void the shingle warranty", attic ventilation has very little effect on shingle temperature.

Conditioned attics are now finally allowed in the IRC building code, which Denver uses, but they should be mandatory. They can be accomplished at little to no cost, because they eliminate the often tricky attic ventilation requirements.

Monday, September 3, 2007

The simplest steps to a better wall.

Two easy changes can be made to conventional wall building:

1. Start by framing on 24" centers:
Optimum Value Engineering
It's hard to get experienced framers to change their ways, but this saves a lot of wood with some extra design time. You have to give them a drawing that shows every stud and header location and configuration.

2. Thermal bridging is a big issue in stud walls. Dow Styrofoam helps at almost no extra cost. Note that it eliminates most of the (rot prone) OSB in the structure, and if you tape the joints, it eliminates all the Tyvek. "Styrofoam insulating sheathing" keeps most of the water at least 1/2" away from all the wood in the house. Nice.