Friday, November 27, 2009

Starting Soon!

We signed all of the papers earlier this week and will meet Don and the foundation contractor on Monday the 30th. They will be marking off the areas for the driveway, retaining walls, and slabs. A number of trees will be removed, but we are trying to save the hardwoods. So, we drove up today to take some pictures before the clearing gets started. These two were enjoying wildflower nectar. Do you see the well-camouflaged one?

The property is overgrown with Ashe Juniper trees, which are commonly called Cedar. Cedars are considered a nuisance in this area. They take the available water away from other trees and many people are allergic to their pollen. So, we will be removing many cedars and either chipping them up for mulch or saving the trunks for fence posts.

To get an idea of how thick they are, this photo shows the area of the street where the driveway will start. The cedars are the ones with deep green foliage.

It was a grey day. The next two pictures were taken close to the area where the house will sit. The first is the view toward the southwest, the second toward the southeast. Even at this distance, you can see how low Lake Travis is. Even after several recent rains, it is still 16.6 feet below its average November Level.

Thursday, November 26, 2009

Framing, Insulation, and Solar

As mentioned in an earlier post, we had looked at many new alternative materials for framing. ICFs, SIPs, and pre-fab were really interesting and had many advantages. We really wanted steel framing and had looked at companies that provide steel frame kits. A company nearby in Georgetown, Transcon Steel, fabricates steel panel systems. These would have been great to use and we got a bid from them that was very reasonable.

Since we're building on a steep lot, the retaining walls and site prep add significantly to the cost of the home. The local Jonestown ordinance requires a two car garage. As you can imagine, it requires a lot of concrete to support a structure on a 38% grade. And, the driveway can only be 12-15%, so quite a bit of the budget goes toward that as well. We tried to get a variance to avoid having to build the garage, but were turned down. So, with the added cost of the garage itself and the concrete to retain it, it looks like we'll have to go with conventional stick-built construction.

Even stick-built can be "greened." Our builder, Don, has specified finger jointed studs, which are made from shorter pieces of wood glued together. They make use of lumber that might otherwise be wasted and they tend to not warp like conventional studs. The Austin Green Building website has more information. Don also orders carefully to avoid as much waste as possible.

For a tight envelope, the walls will have 3.5" of sprayed foam insulation. The floor will be partly slab and partly on pier and beam, which will also be insulated. The Attic will be completely insulated with 5.5" of foam. This insulation allows the air conditioning to be more efficient with ducts running in air conditioned space instead of in a 140 degree solar oven. The metal roof will reflect heat and provide a good surface for rainwater collection.

We plan for a small solar photo-voltaic installation, a little over 3Kw. And, if the budget allows, we'd like to have a wind turbine as well. More details on these systems later.

Saturday, November 21, 2009

Lower Level Floorplan and Rainwater Collection

This is the lower level. Since you probably can't read the annotations, the largest room is a media room with space for a 7' pool table. The two guest bedrooms are at the top. The outdoor living space is covered by the deck above it, which will also help shade the windows.

The two round circles to the left are for rain water collection. Water is short here in Texas and last year was extremely dry. However, when it rains--it pours. We're estimating that we will be able to collect from approximately 1000 square feet of the roof. That should produce 550 gallons of water for every inch of rain. The average rainfall in our area is about 32 inches, which would yield 17,600 gallons.

The average family of two uses 20,000 gallons a year. However, our fixtures will all be water savers and we are installing a Brac greywater system that reuses the water from the shower and laundry to flush toilets. We could always have water trucked in if necessary, and it is possible to add gutters to the garage in the future.

Street Level Floorplan

This is the street level floorplan. We only have a scanned image, so it may be difficult to see the details, but hopefully you can make out the main layout. As you can see from the elevations we posted previously, the house steps down with the hillside. The main living area is over the smaller bottom level. We tried to incorporate all of our needs in a "not-so-big" house, using some of the principles outlined by Susanne Susanka. The total conditioned/heated square footage is about 1380 for the top floor and 863 downstairs. We probably wouldn't have needed the space downstairs, but most of our family and many friends live elsewhere and we hope they will visit often. The downstairs will function as a private suite when we do have guests--sound inviting?

We went with a custom design for our home because we weren't able to find all of the following characteristics in existing houses or in one stock plan:
  • One entry for us and our guests.
  • An ample closet in the entry for coats with shelves for shoes, purses, a charging station for electronics, and all of the things that usually end up on the top of a table near the entry. Significant environmental pollutants can enter the home on the bottom of shoes. We plan to have separate footwear for inside and outside.
  • An open floorplan with lots of windows facing the view.
  • A small office. After years of working in cubicles, this space is more than ample. It will have double doors with glass to close for privacy, while enabling us to still see the view through the living space.
  • A powder room that does not open off the main living area. You enter it through the office.
  • A large pantry.
  • A kitchen with separate areas (and sinks) for cooking and cleanup. No longer should we be bumping into each other.
  • A Japanese soaking tub. I've never been able to get comfortable in a normal tub. This one has a seat and requires less water to cover you up to the neck. It's more like a personal jacuzzi than a tub, but without jets. See a description on the Americh site.
  • A large walk-in shower.
  • Laundry in the walk-in closet. Why transport dirty and clean clothes back and forth when you can simply throw them in the washer and hang them up when clean?

Wednesday, November 18, 2009

Side Elevations and Passive Solar

You might wonder exactly what makes our home green. Just like the color, eco-design has varying shades. We've tried to incorporate all of the green elements that we could afford. One green principle that costs little to nothing is Passive Solar, which includes correct orientation of the home to the sun and the placement of windows.

If the long sides of a home face north and south and the windows are placed correctly, you can significantly reduce cooling bills in the summer and heating bills in the winter. Here in Texas, cooling is much more expensive than heating, but we do get a few months that require heat. While windows gain and lose heat much quicker than an insulated wall or roof, they also provide light to cheer the soul and reduce the need for electricity during the day.

The first elevation of our home shown above faces north. It has only a few windows, which provide daylighting but minimize heat gain and loss. The second elevation is to the south. This side offers a view of Lake Travis and contains the most glazing. To reduce heat gain in the summer, the largest windows are covered by the roof over the deck and patio. The other windows are either covered by a roof overhang or by individual roof awnings. The overhangs and awnings are calculated to provide the most shade in the summer when the sun is high in the sky.