Although there is some acknowledgement to the benefits of having 'green' or sustainable buildings, where energy, waste and water conservation are priorities, many do not take into consideration the financial and health benefits associated with good IAQ. "Many buildings today are designed and built without a clear understanding of how the indoor environment impacts worker productivity and health, and as a result often create an environment that inhibits productivity rather than enhances it". One study quoted, when referring to increased ventilation rates as, ".additional ventilation costs were $8,020 and sick leave costs associated with lower ventilation rates were $48,000, a savings of $39, 950 per 100 corporate employees could be obtained by investing in a higher ventilation rate. Applying this same example to fulltime workers in the US , the cost of sick leave is $24,444 per 100 workers. If higher ventilation rates are used, a potential savings of $16, 394 per 100 workers could be achieved (reported in 1997 US dollars)". When utilized correctly, IAQ and Energy Conservation can go hand in hand.