I have decided to build my first home, by myself as much as possible. My budget is definitely smallish, but I already have a good level bit of land and I have never felt the need for a huge house.

Background info on the land itself: 1 acre about 45 minutes south of San Antonio, TX. Completely undeveloped, I don't think it's ever even been plowed, just grazed on by a few pet llamas. Sunny days average between 45-75% year round, so I think solar power could be feasible as a way to cut the energy I buy. No water on the property, and windy days are rare.

I'm presently looking at the possibilities of a straw bale house and creating a bermed underground house. San Antonio is a fairly dry area, and the field I've chosen is not in a flood plain. Does anyone have experience or knowledge of these types of homes?

This is just my first decision of hundreds, I'm sure, and I would appreciate any input that I can get on it.

Have you asked the City of San Antonio about any programs they may have to support green building, such as tax breaks, discounts on energy bills, low interest loans to install solar power, etc.?  I live in Santa Monica, CA, and the city offers many such helpful programs to residents willing and able to build green or even upgrade to more enegy-efficient living -- maybe you could cut a few costs while building your dream home! Best of Luck!

Congratulations on building your home... and good luck. I'd love to be able to do such a thing, but good luck finding an empty plot of land around Boston that is halfway affordable.

As cems65 said, check with San Antonio, the state of Texas and the Feds about tax breaks/discounts/loans/etc. when it comes to renewable and sustainable energy. Your power company may also be in a program where if your home generates more power than it uses (via solar or wind, for example) it will buy that energy from you. Some people are able to even make money (not a lot, but it's better than paying it!) monthly by doing this. You don't make money in the long run due to the high cost of installation of the equipment, but every little bit helps defray that initial investment.

To begin with, you need to consider local conditions. In hot and arid climate your main objective is to protect yourself from heat gain. Most heat is gained here through the roof; therefore I would recommend a flat roof with white top coat with high reflectivity ratio to create a cool roof effect. Single story, compact type house (1:1.3 with a patio/court inside. Next to roof the most heat is gained from east and West side, so most windows should be oriented toward South and North.  Extensive window shading devices (deep overhangs or awnings) on the south side. If windows are needed on the West or East side, use SolarBan or similar insulated glazing to reflect heat as much as possible. Try to place uninhabited spaces on the West side to provide heat buffer for other areas.
On low budget,  I would stay with traditional building techniques which will allow you to shop for most competitive prices. 2x6 studs on exterior walls should allow decent insulation. Straw bale construction, if you find it feasible, offers even better insulation and deep walls which work very well in dry climate. Good luck!

Krys