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.

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.

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.

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!

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.

Zoning Code Update

"Final Release" of Denver's new zoning code has now been posted:
www.newcodedenver.com

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.