A cube is the most efficient use of volume and surface material therefore it will save money. Unfortunately, that's about all it does unless you think a cube is attractive. One way to soften the shape is to bring a sloped roof down over a garage or other one story space.

I would not go too far with style or shape without analyzing the site constraints/opportunities, your program, the climate, and your lifestyle.

From your blog:

"It seems that the 90 degree angle truly is the "right" way to build a house and the ideal shape which holds the most volume while tolerating nothing more or less than 90 degrees is the perfect cube."

That is mathematically untrue. A cube uses up a relatively large amount of surface area to enclose a relatively small amount of space.

For regular polyhedrons, the more sides there are, the more space enclosed for the same surface area. As you correctly pointed out in your blog, a true sphere (which has an infinite number of sides) encloses the greatest amount of space for the smallest surface area. So the more sides a polyhedron has (the more it resembles a sphere) the more efficient it is in regard to enclosing space.

Among regular polyhedrons, the cube is the second WORST shape for efficiently enclosing space. Only a tetrahedron (which only has four sides) is worse.

An octagon house, rather than a cubical one, would much better meet your criteria of maximum space enclosed with minimum surface area. The octagon house has eight identical outside walls, a floor and a roof, making a total of ten outside surfaces instead of the six that a cube has.

The link shows some examples.

Here is a link that might be useful: octogon house plans

The observations about the efficiency of cubes are made in the context of efficient, conventional construction techniques, structural systems, and materials compared with similar shapes with unequal sides.

is this a home or a science project?

In a determination of the ideal form of a house, an additional factor, beyond efficient construction, is efficient use of money. In the broadest sense that would include resale.

A beautiful home, therefore, is sometimes the most efficient home.

A cube or polyhedron is likely to be very inefficient come resale. ;-)

As I pointed out earlier, this is usually the wrong point of departure for designing a house if you want it to be a good one. It reminds me of my first design class where everyone designed a house and then tried to put it on the site and got graded down for it. It took me 15 years to learn how to design a house since I didn't pay much attention to the advice of others, so I can't expect people here to do it.

Speaking of unusually-shaped houses, it so happens that the DH and I are the owners of a trapezoidal-shaped house that we built on our lakefront lot in 2002.

The shorter side of the trapezoid is the front (lakeside) wall of the house. The side walls taper outwardly to a longer, rear wall which backs up to the forest. The side walls are tapered enough that we get lake views from both of them. Thus, we have lake views from three sides of the house, which wouldn't be true if the house were a simple (but more efficient) rectangle.

In addition, the house has a flat roof, which slopes down from a 13-foot height in front to eight feet in the rear. This also maximizes the lake views.

To my mind, the single most important factor in house design is the building site. A design may theorectically look like the most beautiful, most efficient house in the world, but if it doesn't harmonize with the site and exploit the opportunities of view and orientation the site offers, than it will be a dud.

How would Falling Water look, do you think, out on the Arizona desert?

Actually, Falling Water is so classically balanced from all viewpoints, that if equally poised on a cliff, it probably would look quite good in the starkness of a true desert site. Imagine it with the sun setting.

Sorry, ooopie, that was off-topic.

Personally, I'd use a pure cube or rectangle only if I were totally comfortable with those shapes. Same goes for a geodisic dome house and feedingfrenzy's trapezoidal.

While the manipulation of shapes, both interior and exterior, can contribute to a house's efficiency, I think you'll find that real life imposes other considerations that are of higher value. Site facing to take advantage of solar heat (or shade if in a torrid climate); insulation, and careful construction will be of far more importance than whether the building is a rectangle or a cube or any variety of geodisic.

Balancing the constructual consideration is the fact that your personality will likely be drawn more to a particular style, and you will be more at ease working within that style [and with making that particular form more efficient]. It doesn't matter whether you are more comfortable with a Cape Cod or a Dome, or a stark cube or a hacienda, a cottage or a mansion or a tract ranch house. Each of those styles can be designed and built so as to be highly efficient because efficiency is the end result of choices made before and during construction regarding materials and care in building which have little to do with whether the final shape is a tepee or a tower.

That said, keep in mind that human nature seems more inclined to take care when the object is simple; thus, a plain hip roof is more likely to be sealed, caulked, faced, lined, shingled, etc with fewer problems than the same installation method and material which also requires working with gables and other angles. i.e. The very number of angles which makes a geodesic dome space efficient is a handicap when it comes to sealing and waterproofing all those angles. But proper sealing and waterproofing are of more importance to an overall efficient house than is the fact that a dome is more space efficient than a cube.

Thank you all for your straight forward words of insight. How great it is to receive so many different perspectives, and exactly why I am doing the project like this.

I chose to begin my thinking with the general shape of the house because I believe it to be one of the most important decisions and one that should determine many others. My starting point is a cube because I believe it to be a very effective shape.

How closely the final draft will resemble a cube is yet to be determined, and many of the things you all pointed out will be large factors in determining this.

Yes I'm treating this design much like a science experiment, examining function, designing around that, and holding faith that the end result will be beautiful, much like a tree is designed to function, determined largely by math, yet stands beautiful.

I am beginning a thought process, and keeping it exposed step by step. Where do you all begin your process?

Here is a link that might be useful: my blog

If you and your wife are going to build this, remember that stairs are difficult to build. Also getting on top of a second story roof is much scarier than a one story.

Also, it will be difficult to get material to the second story.

Efficient isn't always safe! A low-slung one story would probably be much better.

I started by looking at on-line plans and buying plan books and after looking at two or three thousand plans, found one close to what I want. Now I will take that plan to an architect and have him/her make the changes I want.

Someone close to me is designing their own home from scratch and so far the design is awful. A guaranteed money pit that will likely depreciate.

Jon, I went to your web site and see that you have an interesting project. I don't have a Goggle Account so will comment here.

If I remember correctly your blog shows four example pics of cube homes. Of those, the two photos where you could discern the site of the cube home, both were in the desert. You are in Connecticut I think. A flat roof in Connecticut might be troublesome because I think it rains and snows there a fair amount.

I don't think many old homes in Connecticut have flat roofs. Your blog mentions being open to ideas. I am by no means an authority but you may want to be open to the idea that those who came before us were smart in rejecting flat roofs in climates with significant amounts of precipitation.

Good luck, but I think you'd be much better off adopting a plan like the current thread on "modern barns" is suggesting.

However, there are some smart folks here who may be able to help you realize your vision.

Terry

Ouch Terry! I hope you're not referring to my money pit, I mean house! :)

To the OP - I only glanced at your blog, but wanted to add that exposure direction makes a difference to the HVAC sizing. Although I would argue that if you wanted to be energy efficient, you could elect to eliminate all windows, in which case the orientation of your house wouldn't matter.

I know somebody who wants to build a modern house with a flat concrete roof, but he found that the insurance would be much more expensive. Something to check on.

Carter... Yeah, I just re-read my post... I see that I could worded that a bit better.

And the person "close to me" ....well, I was referring to a relative!

My apologies....

Terry

I can appreciate you wanting to build in an efficient manner; however, you will live there. What appeals to you? What turns you on? What vacations have been the most positive for you with respect to your accommodations? Do you want to be transported when you walk into your home each evening.

As I asked those questions, I realized that DH and I love the the outdoors and yet, we hate the heat here in Missouri. As a result, we have front and back porches (back porch has electric phantom screens for "buggy" season), both covered and both with ceiling fans. Our vacations that we enjoyed the most were out "West" in the mountains. Granted, Missouri does not have mountains, but we have a hilly wooded lot so our home embodies lodge features that appeal to us aesthetically. It was important to us that our home "fit" the site, weather and solar wise. In CT, you have many historical areas to explore with fine examples of homes that were built to efficiently deal with weather, solar and precipitation issues.

It is important to list your priorities--a fancy gabled roof did nothing for us so we put our dollars into features that appealed to us; i.e., the porches.

Good luck. You will have many decisions to make; however, this site helped me enormously (thank goodness as we moved in three days ago) so you will have expert support here.

Teresa