Greening Our Built World: Costs, Benefits, and Strategies
About this book
"Greening Our Built World: Costs, Benefits, and Strategies," published by Island Press in 2010, is a comprehensive evidence-based study by Greg Kats of the financial and non-financial costs and benefits of green building. Drawing on detailed analyses of more than 170 certified green buildings across the United States and ten other countries, the book challenged the widespread assumption that green building is expensive—demonstrating that the actual cost premium is modest and that the financial, health, and productivity benefits far outweigh it. The book has been widely cited as one of the most rigorous quantitative assessments of the business case for sustainable building ever conducted.
The fundamental question that the book addresses is: does green building actually make financial sense? At the time of publication, the green building industry was growing rapidly, but a persistent assumption among developers, investors, and building owners was that green building required substantial additional investment that was difficult or impossible to recover through operational savings. Kats and his co-authors—Jon Braman and Michael James—set out to test this assumption rigorously against empirical data from a large sample of actual certified buildings.
Their central finding was striking: the average cost premium for building green was approximately 2% above the cost of conventional construction—far less than widely assumed, and the absolute cost premium across the sample ranged from zero (some green buildings cost no more to build than conventional equivalents) to $71 per square foot, with a median of just $3.40 per square foot. This finding alone was significant, demonstrating that the cost barrier to green building had been substantially overstated in public and industry discourse. The analysis of benefits was even more compelling.
Energy use in certified green buildings was on average 33% lower than in conventional buildings—a reduction that, at prevailing energy prices, generated substantial operating cost savings over the lifetime of the building. Water use was typically 30-50% lower. Reduced maintenance costs, lower liability exposure, and higher property values contributed additional financial benefits.
However, the book's most important contribution was its rigorous treatment of the health and productivity benefits of green buildings—benefits that had been recognised qualitatively but rarely quantified. Drawing on occupant surveys, absenteeism data, and studies of the relationship between indoor environmental quality and worker productivity, Kats and his team estimated that the health and productivity benefits of green buildings—measured in reduced sick days, improved cognitive performance, lower staff turnover, and higher employee satisfaction—were typically worth between $40 and $75 per square foot over a typical building's life, compared to a construction cost premium of $3-5 per square foot. In other words, the non-energy benefits of green building were an order of magnitude larger than the additional cost.
The book examines green building across multiple sectors—commercial offices, schools, retail buildings, healthcare facilities, and residential construction—and demonstrates that the financial case for green building varies significantly across these sectors but is positive in all of them. The school buildings chapter is particularly notable: it presents evidence that green schools improve student attendance, academic performance, and teacher retention, generating educational benefits worth many times the additional construction cost. The book also presents the results of what was at the time the first-ever survey of green buildings constructed by faith-based organisations, demonstrating that the motivations for green building extend beyond financial calculation to include ethical and stewardship values.
Sources: Island Press; Amazon; Smart Surfaces Coalition; Semantic Scholar.