Our climate is also very extreme high desert, but I think our summers are not as hot as yours. Winters are good and cold though, similar to northern US with first frosts in Sept to Oct, and 6 weeks of
pond hockey in the neighborhood.
I've become very fond of the removable seasonal greenhouses we use to heat our houses at the school I work at, and now at my own house. We use UV resistant polythene, and remove it in April or May, and attach it in October or November. I find it very very helpful to have doors or windows in the E and W ends of the greenhouse for the shoulder season, so I can close them at night and open them in the day to relieve overheating in the greenhouse during the shoulder season. But in our intense high desert sun, no amount of end ventilation would prevent overheating in summer in a greenhouse, and I love having it off and the garden exposed to the sky and air and weather for the summer.
A perfectly south facing wall with the main windows is best for the rooms to be kept warm in winter and cool in summer. Perfectly south facing walls get good penetration from the low sun in winter, and no penetration by the high sun in summer. A small overhang over the south-facing windows helps even more.. Every degree you go off of perfect south contributes to overheating in summer.
West windows are the worst for overheating, because when the house is already warm from the ambient heat of the day, it then gets blasted with the hot afternoon sun. East and north facing windows do receive a little sun in the summer so they also contribute to overheating a little, but not as bad as west facing windows. South facing windows with an overhang actually get no direct sun at all in the weeks around the summer solstice. Later in the summer, like August, I do get a bit of overheating as the sun comes down a little.