Ive read, and believe that building up is cheaper than building out. less foundation, and less roof. BUT BUT BUT, a two story is presenting some challenges for my situation. basic rectangular shape with no bumpouts or garage, and simple gable roof. 1. main thing is I want the walls and windows in full shade from end of march till end of September. this is easy to achieve with single story, harder to do it aesthetically with a two story. 2. I want to build as much of it as possible by myself. this may involve doing the roofing, or the siding. a two story is going to be more challenging in this respect. so, what considerations exist that may make a single story cheaper to build than a two story.

one thing I hadn't thought about is that a stair case can eat up 180 sq ft, so apples to apples a one story can maybe be smaller for the same amount of living sq footage?

thoughts?

If you have a basement the stair case cancels because you still need one for the basement and they are usually over each other in the two story. I think it is more like 50 sqft per floor.

The best utilization/minimization of outside surface is a square, so the closer you keep it to a square the better.....just make a 10 by 10 by 10 house

but, 10x10x8 would be more efficient, no?

i kid.

Im in texas where we usually dont have basements. this will be slab or maybe pier and beam.

Energy use is smaller in a two-story. Roofs in a typical house lose more heat than windows. A two-story automatically halves that loss. Of course, "typical" is not typical in a house designed specifically for energy conservation. Climate and site orientation are so key to design that no one here can tell you which loss to minimize, aside from minimizing everything. Go here, pick an energy modeling tool and have at it. https://www.buildingenergysoftwaretools.com/ I used HEED a decade ago but folks here know today's choices better than I, including poster sailawayrb who has her own free software on offer here.

Couple points: My spiral staircase takes up 70 sf. You'll need a second entry for furniture moving. Mine is a 4-foot stairs leading to a garage-top deck. Window placement and design can substitute for overhangs. North walls are shaded 365. A front porch together with a large roof overhang keeps south facing windows shaded through summer. As for roofs, the steep slopes Texans favored on one stories in my day are much harder to work on than a reasonable pitch on a two-story.

Which brings me to a subject not often broached here. You will not spend 100 percent of your waking hours in your home admiring your electric bills. If you have a view, put a window there and use your green smarts to find a way to live with it. To start with energy conservation is working backward.

The roof losses of an R49 roof are small enough that cutting in in half is "in the noise" of other heat loss issues. From an energy use point of view while a simple cube with a gable is more efficient (less exterior surface area per square foot of living space), making it a 2x1 single story rectangle with a gable with twice the roof losses but only 3/4 the wall losses can be in the same range. A lot depends on your wall stackup & window choices.

Energy modeling tools are the right way to tweak a house design for energy efficiency. The free DOE download BeOpt is pretty good, designed to compare cost effectiveness of different energy measures against each other.

OK, a story and a half bungalow with a wrap-around porch and deep overhangs. Or a farmhouse with similar porch and overhangs. Either design reduces exposed wall in addition to roof size. More importantly, either design fits in Texas because they were built there in the 1900s and 1930s for the exact reason OP thinks he needs a one-story house. August was just as hot then minus AC and insulation. Don't like old-school? How about a modern design dominated by second floor balcony a la Wright's Falling Water. (OK, maybe not as dramatic as Falling Water.) Or plain ole Texas subdivision curb-appeal-for-the-masses, whatever style that is today. Shade it with pergolas, decorative screens and plantings.

Unless OP wants his house to scream I am an energy nerd, he shouldn't be ruling out architecture decisions based on energy priorities.

Todd, I want my house to scream I am an energy nerd lol.
If you saw the alternative here in Texas you would be bewildered.
I do believe in vitruvian architecture philosophy:
Usable,durable, beautiful.

So many things make me scratch my head regarding home design and I'm sure some have good reasons I just haven't found them yet.

Why do we face the front of the house to the street? For example?
Why are so many design choices inspired by vanity?

Anyhow,the pursuit of simplicity and efficiency speak to me.

Im not too concerned about the view outside from inside the house. I think if one wants to enjoy the view, one should go outside.

I hope there is no rule against posting links but this is what I think of as perfect house design
https://goo.gl/images/DVP8wm

Simplicity and efficiency speak to me as well. But Vitruvius argued for three pillars of architecture: utility, strength and appeal. That said, the only opinion that counts on the last is yours.

Sketchup is 3-D modeling software developed initially by Google. It was free and downloadable back when. The free version is web-based and collaborative in the sense that your work is out there along with everyone else's. I spent a couple years with it. My goal was to wring out every square foot in a footprint that was 1600sf o/a. You might sldo want to read the The Not So Big House (website here: http://notsobighouse.com)

Enjoy. The only thing more satisfying than seeing your creation take shape on the computer is to see it rise from the ground.

Posted By toddm on 31 Oct 2018 04:32 PM
Simplicity and efficiency speak to me as well. But Vitruvius argued for three pillars of architecture: utility, strength and appeal. That said, the only opinion that counts on the last is yours.

Sketchup is 3-D modeling software developed initially by Google. It was free and downloadable back when. The free version is web-based and collaborative in the sense that your work is out there along with everyone else's. I spent a couple years with it. My goal was to wring out every square foot in a footprint that was 1600sf o/a. You might sldo want to read the The Not So Big House (website here: http://notsobighouse.com)

Enjoy. The only thing more satisfying than seeing your creation take shape on the computer is to see it rise from the ground.

Thank you for the link. I'll check it out. I definitely want to have the house fully completed in CAD before I ever but the first 2x4. I've used SketchUp a bit but I'm thinking of something like the scaled down version of chief architect since it for some things automatically like framing design, electrical, plumbing. I like free though so I will give SketchUp another look. I want to do what you did-use every inch. 3 bed 2 bath, no garage , no North facing windows. It will be challenging but I have time. Did you come up with a workable design? I have little creativity and I find the idea of designing my own house daunting.

Let's say it worked and it is a very livable house. Keep it simple. Elements that are easy to design on a computer, such as an exterior wall radius that follows the curve of the spiral staircase, turn out to be very difficult to replicate in block and wood. And don't get too greedy for space. I crammed all of the mechanicals into a chase 4.5' square and open through the roof to 23'. With concrete bond beams to bolt to, I mounted the mechanicals in four levels. Then I discovered that I needed a whole-house water filter. And a dehumidifier. And a second heat pump in the form of a ceiling cassette. (The chase circulates air between floors which proved to be insufficient cooling on super hot days and insufficient dehu during the shoulder seasons when dehu by mini means donning sweaters.) In short, I hope the guy who replaces my water heater isn't me.

Start by googling houses in the style you like. My guide was Frank Lloyd Wright, who designed a few hundred small, affordable houses in a style he called Usonian, which lives on as the rancher. They were basically shotgun houses, typically in an L shape with lots of south-facing glass looking out on a patio. (Gotta say the most important wall in a small house is the one that isn't there (i.e. is glass.) The design minimizes space lost to walls. I have 42 linear feet of interior walls in a 1000 sf downstairs that divide off a den and a bath and a pantry.from the great room. Upstairs it's 55 feet in 600 sf marking off two bedrooms with walkins and a bath. Then built-ins to add storage . Read small-house books for tips.

You'll probably find some designs you like in Sketchup's design warehouse. Dunno how easy it is to start conversations on the online Sketchup, but talking to someone who has been there with your design is golden. Then start designing. You don't have to get it right the first time or the 32nd time. In a slow burn over a year or more, solutions will pop into your head. Nor do you need creativity necessarily. All you need is a guiding principal: Steal from the best. If you know what you want, you'll find it in time.

Posted By patonbike on 06 Dec 2018 10:46 PM

to some degree i would consider what is normal in your area. you may or may not want to build something that sticks out from the norm.

unlikely 2500 sq ft on 1 floor will be less than 2500 sq ft on 2 floors.  You have half as much roof and concrete.

you are right, although when considering a high performance wall, the difference is not that much. I compared a roughly 2500 sq ft one story to a roughly 2500 sq ft two story. the one story has about 20k more in roof and foundation, but the two story has about 11k more in walls(SIPS in this case) . so with the cost of stairs, additional cost of labor(Im assuming) it seems it could be almost a wash