When we started this project we wanted to create a home that would reflect our love of nature and our careers in technology.  This is not a contradiction!

The primary challenge is to create a design that is simple, cost effective, efficient and attractive.  It's not an easy challenge and we have loooked to mid-century modern, Frank Lloyd Wright 'Usonian' and Japanese architecture for inspiriation.  All updated to take advantage of contemporary materials and technology.

In a sense, our goal is to create a mid-century design for the middle of the 21st century.   No one knows what the world will look like in 2040 or 2050 but it's safe to assume that increasing population will place ever greater demands on natural resources, energy and land.   A responsible design should use recycled and durable materials wherever practical.

Passive design greatly reduces the need for complex mechanical systems that consume energy, break down and require maintenance.   Simplicity contributes to sustainability.  This is highlighted in a great graphic from Albert, Righter and Tittman Architects.   http://www.alriti.com/sustainability/index.php

The terrain at our site is very rocky with only a foot or two of top soil.   There are a lot of 50 - 100 year old trees on the site that have adapted to the conditions, but storms and wind have taken their toll.

There were several large trees that had been blown down over the years. Some of these were leaning against healthy trees we wanted to preserve so our first order of business after the survey was to remove the 'leaners'.

The lot sure looks different when the foliage is up.

After we marked the trees, we had a tree service remove dead trees and leaners.  

It's a shame that this old hickory blew over.  It's leaning up against an even bigger oak, just off camera.

For perspective, that's a man next to the tree.

We will definately be using wood as our back-up heat source.

When you're building on a sloping site it's really important to get an accurate topographical survey of the site.

We hired Frontline Surveying and Mapping from Marietta to do the topographic survey for neoTerra.  We had them do a 2-foot contour interval.  Since one of our goals is to preserve as many of the larger trees as possible, we also asked them to plot the locations of the larger trees in the potential construction area. 

The crew from Frontline was great.   They arrived right on time and walked the site with us to get a good understanding of where we planned to site the house and the trees we wanted to plot.

After we received the survey, I constructed a scale model of the site using foamcore.   I glued copies of the survey to foamcore using spay adhesive and then made cut outs at 5 foot intervals using an x-acto knife.   Stack them up with some Elmers glue to get a nice 3D terrain model.

You can orient the model to face true south and get an idea of how the sun will illuminate the site.

Since we are working on the design remotely from Chicago, we marked about 20 trees with numbers on green tape and put the ID's on the topographical map.  It's surprisingly difficult to describe locations on a wooded site and the IDs make it much easier when you're talking with a subcontractor on their cell phone.

Simple things like this can help a lot when you're working remotely.   If someone cuts the wrong tree(s) down it will take 50 years to grow new ones.
 

When we decided that we wanted to build a passive solar home we started using our vacation time to explore different parts of the country and look for the perfect site.

We've lived in big northern cities most of our lives and we wanted to relocate to a more moderate climate with more outdoor recreational opportunities.  But, we also enjoy the change of seasons so we wanted an area that has fall colors and a little snow in the winter.


After several trips we narrowed our choices to either the Ozarks region of NW Arkansas or the southern edge of the Appalachians in North Georgia / Western North Carolina.

Land is inexpensive in Arkansas and we came close to purchasing a 47 acre site near Eureka Springs.  It had a spectacular building site on top of a towering stone bluff.   Arkansas has a midwestern feel to it and a long heritage of modern architecture from E. Fey Jones.

Ultimately, we decided on North Georgia.   We were attracted by the mountains, the vast expanses of National Forest, the history of the region and the proximity to a major, metropolitan city.

We looked at more than 45 different sites and finally found one that has great south and southwest exposures and a lot of mature oaks and hickories that will shade the house in the summer.

I'm an owner-builder and I've been interested in passive-solar design for more than 20 years.   I built my current house in Chicago in 1991.  It is well insulated (for the time), has lots of south facing glass and deep overhangs designed to block summer sun.

I used high quality dual-pane, argon-filled glazing. Unfortunately, there wasn't much thought about solar heat gain coefficient (SHGC) in 1991 and my windows are low SHGC.   The house collects far less heat than you might imagine from all those south windows.

In addition, I was concerned about resale so I used conventional wood frame floors with wall-to-wall carpeting. This doesn't provide the thermal mass needed for a true passive solar design.

The house works pretty well in spite of these limitations.   The lessons learned are to use high SHGC glazing for south facing windows and insure that there is enough thermal mass on floors or walls that directly receive sunlight to absorb heat during the day and release it slowly at night.  Here is an excellent link on high solar gain glazing.

http://www.greenbuildingadvisor.com/blogs/dept/musings/high-solar-gain-glazing