TABLE OF CONTENTS - The Professional Green Building Council

Theme B: Creating a livable, healthy and environmentally viable cities4.4 Water Conservation – Use of Reclaimed WaterCondensate from air-conditioning system will be reclaimed for irrigation purposefor water conservation. The amount of reclaimed A/C condensate wouldadequately cater for irrigation at Levels 1, 3 and 4, podium roof, as well as the softlandscape on L4 open plaza. Assuming the amount of water required for irrigationto be 2 L/ m² / day, the estimated annual cost saving for fresh water consumption isapproximate US$2,400.5. ECOLOGICAL FOOTPRINT5.1 Definition of ecological footprintThe ecological footprint is the predominant methodology used to highlight theimpacts of consumption within the context of ecological limits. The methodologyhas been increasing in popularity since its initial publication by Wackernagel andRees in the 1990’s [2]. The footprint is a means of measuring a population’s levelof consumption by calculating the notional and direct land area needed to supportthem with the resources they consume and absorb the wastes they generate. Theecological footprint is measured in global hectares (gha) which means that the landcan be located anywhere in the world and is representative of a standardized unit ofaverage global productivity. In this manner the ecological footprint reallocates theenvironmental impact to the end user no matter where in the world the impacttakes place. Ecological footprint calculation can take either a bottom up [3] or topdown [4] approach, or use a combination of both.Independent of the methodology used to conduct an ecological footprint study, oneof the most important messages that it conveys is that we only have one planetwith a finite land area therefore clearly demonstrating that we are constrained byecological limits.Different from traditional environmental indicators, such as the Kyoto climatechange targets, for which impacts are measured within a defined boundary such asa country, the ecological footprint takes into account all impacts on a population nomatter where in the world the impacts are taking place. The ecological footprint is210