Posted by: crescendodesignblog | January 6, 2009

Passive Solar Farm House: Keep it Simple and Let Nature Help You

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For a slideshow featuring more images of this project, click HERE.

James Kachadorian’s Passive Solar House concept is as close to an ‘open source’ architectural strategy as any.  Originally motivated by the oil crisis of the 70’s, Kachadorian developed a technique for building new homes that incurred no additional construction costs, based on completely conventional materials, including concrete blocks and poured concrete.  As the patents issued on this solar system expired, Kachadorian essentially turned these ideas over to the public, and wrote a book – ‘The Passive Solar House‘ to ‘make that gift more meaningful.’  The home featured here is built upon the ideas found in this book, as well as direct consultation with Kachadorian himself.

This home consists of an existing farm house, almost every inch of which required total reconstruction with careful consideration paid to energy-efficient construction techniques and mechanical systems.  The new addition extending south from this farm house was built using Kachadorian’s passive solar slab technique.

Aesthetically, the intention was to build a home that fit well with the timeless rural character of this region, especially that of the existing farm house.  We did so by extending consistent overall massing, roof lines, window types and siding material from the farm house to the addition.  The two elements are unified by a central gathering/entry core.

Internally, the addition features an open 2-story central space with a wood stove that can radiate heat throughout all of the spaces in the addition.  The tall chimney minimizes creosote build-up and gives the hot chimney pipe a chance to radiate as much heat as possible into the space.  This open central space is flanked on either side by open second story loft spaces that look out over the living room.  These lofts can be completely enclosed by a series of sliding doors reclaimed from the existing farm house.  These open lofts also enable rising heat from the passive solar slab and wood stove to radiate throughout the entire space.

Internal ‘thermo-shutters’ are located on each of the south-facing windows in order to retain as much of the warmth absorbed during the cold winter days as possible.  They also help keep the space cool in summer by blocking excessive solar gains.  The size and shape of these windows were calculated based on Kachadorian’s guidelines for optimal daylight admittance throughout the year.  We kept north-facing windows to a minimum, and only installed them in areas that would help offset the need to use artificial lights, enabling further energy savings.

The home is currently fit with a solar domestic hot water system, with plans to augment the system with a photovoltaic installation in the future.

In all, this home is not only a model of energy efficiency and passive solar utilization, but fit well with the family’s lifestyle, the architecture of the existing farm house, and the rural vernacular character of this region.

Built by Thompson Custom Builders.

For a slideshow featuring more images of this project, click HERE.



  1. I live in an old farmhousse that I am wanting to build to with more southern and eastern exposure. Yours is very interesting!!

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