Whole System Design

The document advocates for 'whole system design' in home construction and renovation, arguing that considering the interconnections between systems, occupants, and the environment can make green homes cost less than conventional ones. It emphasizes a 'passive before active' approach, prioritizing the building envelope and solar orientation to reduce the need for mechanical heating and cooling. Key strategies include optimizing south-facing glazing, utilizing thermal mass (such as masonry or water), and implementing 'cool roof' or 'green roof' systems. The guide also provides a comparative analysis of wall materials—such as straw bale, adobe, and SIPs—based on thermal performance, toxicity, and cost, while introducing Energy Efficient Mortgages (EEMs) as a financing tool for these improvements.

• Whole system design, also known as 'green design' or 'integrated design,' focuses on the interconnections between systems, occupants, and the environment to solve multiple problems simultaneously, such as energy savings, indoor environmental quality, and affordability.
• Proper building orientation can reduce energy bills by up to 30 percent. In the northern hemisphere, living spaces should be oriented along an east-west axis with the longest walls and largest windows facing south to maximize solar heat gain and lighting.
• To maintain thermal balance, the recommended maximum amount of south-facing glazing is 7 percent of the home's total square footage; exceeding this limit requires additional thermal mass in walls and floors.
• Thermal mass materials, such as masonry, concrete, and adobe, are most effective for passive cooling in climates with high daytime and low nighttime temperatures, such as high-elevation areas of Arizona, New Mexico, and Colorado.
• Cool roof systems, characterized by high reflectance (albedo) and high thermal emittance, can reduce cooling energy needs by 40 percent compared to dark roofs.
• Green roofs provide cooling through plant respiration and reduce the 'heat island effect,' though they have a higher starting cost (approximately $8 per square foot) compared to traditional roofs (approximately $1.25 per square foot).
• Energy Efficient Mortgages (EEMs) allow homeowners to fund efficiency improvements by increasing borrowing capacity based on reduced operating costs or providing interest point reductions, typically requiring a Home Energy Rating Systems (HERS) report.

APA

Yardi, R., Archambault, T., Wang, K., & Eubank, H. (2004). Whole System Design. RMI. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB9WholeSystem.pdf

Chicago

Yardi, Ramola, Tomakin Archambault, Katherine Wang, and Huston Eubank. Whole System Design. RMI, 2004. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB9WholeSystem.pdf.

Wikipedia

{{cite report |last1=Yardi |first1=Ramola |last2=Archambault |first2=Tomakin |last3=Wang |first3=Katherine |last4=Eubank |first4=Huston |title=Whole System Design |publisher=RMI |date=2004 |url=https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB9WholeSystem.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{yardi2004whole, author = {Yardi, Ramola and Archambault, Tomakin and Wang, Katherine and Eubank, Huston}, title = {{Whole System Design}}, institution = {RMI}, year = {2004}, url = {https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB9WholeSystem.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }