PROVINCIA DEL GUAYAS

The development and use of support tools aimed at the building water cycle are limited (Table 2.2). Although still scarce, research on DSSs focusing on sustainable water management at larger scales has produced more detailed and integrated frameworks. For example, Chamberlain et al. (2014) presents a DSS prototype capable of evaluating the environmental, economic, and social effects for sustainable wastewater strategies at the community level. The inclusion of impacts beyond measurable water use is an important component often lacking when the scope is narrowed to building structures and further limited to the water subsystem.

The trend for building-specific water support tools consists of calculators that track estimated water consumption, and thereby view the building water subsystem as a series of divided inflows. These water use calculators are prevalent online, with many published by organizations linked to water awareness and conservation. Homeowners are the main audience for simple calculators; current design patterns or human habits are exposed by

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informing water users of their water consumption habits. The most basic calculators use estimated volumes and flows for water demand applications and allow users to fill in the number of times each application occurs within a given time frame. For example, a user may be asked how often laundry is done or how often a bath is taken during a week. The input parameters provided by the user are fed into equations that produce the amount of water used by the individual either by water sector, all household activities, or both. The time frame may also be changed to reflect daily, weekly, monthly or annual usage. These tools focus on water consumption by demand and are generally not concerned with alternative water sources.

Support tools that incorporate water reuse and recycling or relationships to energy and costs are generally separated from software addressing the entire building. In the case of rainwater, some calculators consider annual precipitation that meets a portion of the irrigation demand, while other programs provide the option for rainwater collection, storage, and use for landscaping or interior building water demands. However, it is easier to find calculators specifically programmed around the design of a rainwater storage and collection system. Some allow users to input specific parameters regarding their building footprint and potential collection area, resulting in the maximum possible volume of rainwater that could be collected. Other tools incorporate storage and cost components to provide better information to users. Calculators developed around a specific water component, such as cooling or irrigation, tend to include a higher level of detail used to model water use for that demand. The Leadership in Energy and Environmental Design (LEED) series of rating systems produced by the USGBC includes calculations outlined to determine water reductions for landscaping and interior building fixtures (USGBC, 2013a-c; USGBC, 2012). As a green building rating system, alternative water supplies are incorporated as strategies to offset potable water demands. However, the current system still relies on a budget approach where water volumes for demands are tallied and compared to available water sources; alternative sources are subtracted from the total demand to determine the total potable water needed by water sector and the percent reduction.

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Table 2.2: Building water support tools.

Name Scale, software Alternative sources Description Water Footprint Calculator (National Geographic, 2013) Single residential, web-based Natural rainwater for landscaping

Daily water use calculated based on household water consumption, personal diet considerations, energy consumption, and consumer spending

WECalc (Pacific Institute, 2010) Single residential, web- based Greywater for landscaping

Extensive questionnaire that calculates total water demand, hot water demand, energy demand, and carbon footprint by end use; also includes costs associated with energy use. Suggestions that reduce energy and water are presented with benefits, costs, and payback periods.

HouseWater Expert (CSIRO, 2004) Single residential, web-based Rainwater storage, greywater diversion, on- site treated wastewater

Water consumption, wastewater generation, and runoff amounts are calculated for Australian regions based on a graphical platform that allows users to choose water demands and sources found both inside and outside of the building structure. The tool includes options for alternative water sources. Wastewater applications are limited to landscaping and toilet flushing.

Assessment tool (Fidar et al., 2010) Single residential, basic tool Greywater reuse, rainwater harvesting

Water consumption, energy use, and greenhouse gas emissions are calculated and compared for 8000 scenarios for an average residence in England. Interior micro-components (water demands) are varied.

WaterSmart Scenario Builder (POLIS, 2010) Community, spreadsheet Input for undisclosed non-potable source (rainwater, greywater, wastewater recycling)

Impacts associated with future water use scenarios for a community are estimated. The community is broken down into residential, commercial and institutions, industrial, agricultural, and non-revenue sectors. Users view impacts of chosen water efficiency scenarios in terms of water, energy, and greenhouse gas emissions reductions.

IBWM Model for Green Building (Joustra, 2010) Generic building, STELLA model (iSee systems) Rainwater, stormwater, recycled wastewaters, reclaimed water

The model provides users with the ability to analyze the effects that water management options have on a building’s water cycle. Various building types are evaluated by changing demand portfolios. Alternative water supplies are incorporated. All demands and sources are networked.

The thoroughness and amount of information both received from and presented to the user dictates the amount of options the user perceives. Calculators that present water usage by sector allow the user to view areas of highest consumption and decide whether design or habitual changes can alter the usage patterns. The user is increasingly exposed to parameters affecting the water cycle when DSS tools require more information from the user. Exposure to

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alternative water sources and demands that can be met by those sources can open the design possibilities available to the user. The fragmented nature of tools that address alternative water supply systems and links to energy and cost hinders the potential for decision-making based on integration. A systems approach allowing for the complete interaction among water sources and demands while identifying the affects to other subsystem will result in DSS tools that are robust and flexible.