Developing Passive Solar Plans

Increasingly, passive solar plans are becoming an integral part of designing new kit homes. More than just house orientation, passive solar house designs are a range of systems, inclusions, materials and construction additions that increase livability without excessive electricity, gas or oil use.

What is passive solar?

Passive solar technologies use sunlight without active mechanical systems. Such technologies convert sunlight into usable heat, cause air-movement for ventilating, or future use, with little use of other energy sources.(Wiki) But passive solar living is more than construction methods.

A passive solar energy philosophy

The ecosystems of our uniquely precious planet earth area complex equilibrium of bio-systems, easily pushed off-balance by excessive exploitation of global resources in ways that damage the environment. The environmental problems caused by extracting energy resources from the earth and the release of greenhouse gases from wasted thermal energy are two such worries.

Solar energy utilisation can eventually eliminate these two worries, by capturing the sun's energy and eliminating the inefficient combustion processes that produce greenhouse gases, such as carbon dioxide.(Terry Galloway: Solar House)

Passive solar plans

A quick planning model can be utilised to guide you through the design process.

Passive Solar plans diagram

Site selection
Initial selection of the building site can make or break your passive design process. A site that reduces options to correctly rotate the house should be avoided. Intimate knowledge of local climates, including prevailing winds, summer maximums and winter minimums, average rainfalls, snow, drought, and extreme weather variance records should be researched.

House layout
By arranging the layout of the house so living areas are moved to the equator side of the house. Also having more equator facing windows and less western windows, a house can gain winter heat and reduce summer heat.

Lot rotation
House orientation is vital to the concept of passive solar design. The house should be aligned with its east west axis (longest ridge) facing the equator. This can be moved up to 20% without too much decrease in effect.

Shown: Northern Hemisphere Orientation Plan (

Solar house orientation

Select building materials
Plan to utilise the concept of thermal mass to absorb heat, so concrete structures and flooring are required. High R value roof, wall and floor insulation, reflective light coloured roofing in hot areas and absorbent dark materials in cooler climates, large equator facing windows as well as clerestory systems as well.

Select solar technologies
Solar panel arrays, grid connection and or battery storage, solar water heating, reversing ceiling fans, attic ventilation systems, low wattage lighting, low kw appliances, and off peak 'time of use' energy consumption will all add to passive solar living.

Go to Sustainable House Design or return to Kit Home Basics homepage

150 best eco ideas