This paper proposes a methodology for enhancing the LifeCycle Cost Analysis of office buildings by accounting for tangibleimprovements in office workers performance and thereforein the employer’s bottom line due to sustainable buildingfeatures. There is a good correlation between indoor environmentalquality and higher worker productivity, wellbeing, jobsatisfaction, and reduced absenteeism all of which help toattract and retain employees. Sustainable buildings contributeto the bottom line for building occupants. Sustainable buildingfeatures add a prestige associated with buildings certified tohigh sustainability levels, increase the building’s market value,increase its rentability, and draw higher rent. This paper presentsan enhanced Life Cycle Cost Analysis of a typical middlesize office building in three different international locationswith a mature market for sustainable buildings. This analysisuses representative European Union and North Americaranges of energy and labor costs, construction costs, and rents,for both sustainable and standard office buildings; andassumes a minimum required productivity increase of 2%, toshow that, for each case analyzed, it is always cost effective tooccupy a sustainable office space or building, whether rentedor owned. Depending on the market, it can be profitable tobuild a sustainable office building for lease to multiple clientsby charging rental rates only 2% to 10% higher than rentscharged for conventional spaces. This paper concludes that thelife cycle cost analysis must account for office labor costsavings resulting from sustainable building features.