Quantifying project uncertainties
August 2010 —AECOM has developed modeling tools and methodologies to help clients clarify the environmental and financial complexities inherent in their projects. The Sustainable Systems Integration Model™ (SSIM™) was developed by AECOM's Design + Planning practice to generate multiple development alternatives, each one rated across a holistic range of sustainability indicators, to help clients determine the most cost-effective sustainability measures. A standalone energy module, SSIMe™, was then developed by AECOM's Building Engineering practice. The PArametric Cost Engineering System (PACES) was developed by AECOM's Economics practice as a cost engineering tool to help plan and budget facility and infrastructure construction and renovation costs. Both SSIM and PACES are specialty tools unique to AECOM that help pull complex projects into focus.
Sustainability simplified
AECOM originally developed SSIM to help private developers meet state-mandated sustainability objectives. In response to federal executive orders and sustainability goals, the methodology has been adapted to model federal infrastructure and determine the optimal set of alternatives to holistically meet energy and water requirements coupled with targeted reductions in vehicle miles traveled, fuel consumption and greenhouse gas emissions. "Meeting and exceeding federal mandates in the most cost-effective manner, reducing long-term operating costs, reducing the total cost of ownership and developing sustainable bases are among the challenges addressed by SSIM," explains Brad Wellington, leader of federal work in AECOM's Design + Planning practice.
AECOM is applying the SSIM methodology to projects of varying scale — from a single building to master plans for large communities. AECOM used SSIM to evaluate various strategies and options to reduce water use at the Smithsonian National Museum of Natural History as part of a water reclamation study. AECOM created a feasibility report evaluating strategies for improving efficiency of fixtures, reclaiming water, supplying water from sub-surface wells, reducing surface runoff water, implementing the separation of the stormwater and sanitary sewer system, identifying potential LEED credits and determining costs and cost-benefits for each of the strategies.
"This study is a pilot project and is anticipated to be extended in the future to all Smithsonian facilities at the National Mall, as well as several additional facilities in the national capital area," said Avinash Srivastava, a technical director for sustainability at AECOM's Design + Planning practice.
AECOM is also using the SSIM methodology and supporting tools for the Guam Sustainability Program at the new Marine Corps base on the island of Guam. "We used SSIM as a decision-making tool to allow Navy and Marine Corps installation leadership to determine the method for how new mandates in energy and water savings, green house gas emission targets and environmental systems objectives would be met as the new base is constructed and put into operation," explains Deanna Weber, associate principal of Design + Planning at AECOM. Briefings were held with the Secretary of Defense, Assistant Secretary of the Navy and at the Headquarters of the Marine Corps levels in Washington, D.C., U.S.A., and the project was warmly received.
This successful demonstration of the SSIM process and tool has led to a follow-on tasking from NAVFAC Pacific for the SSIM team to stay on board and assist with the implementation of the sustainability recommendations as the new base is constructed. Based on the success of the Guam project, the Navy has also commissioned another demonstration project for an existing Navy base to show how the SSIM methodology and decision tool can be applied to re-tooling existing facilities and systems to meet federal mandates and to save scarce resources.
Enabling energy efficiency
In response to recent federal mandates calling for significant reductions of energy use in both existing and new buildings, AECOM's High Performance Buildings Group has developed an standalone energy module of SSIM called SSIMe. The SSIMe tool allows its user to evaluate the benefit of various energy conservation measures (ECMs) that could be incorporated within a building to improve its energy efficiency. A range of ECMs can be evaluated by the SSIMe process, including HVAC systems, lighting systems and renewable energy solutions.
AECOM building physicist Andrew Bickerdyke, who was key to the development of the SSIMe tool, noted that "SSIMe's live gaming approach allows us to align our building energy efficiency strategies more closely to the client's needs, whether to inform a master plan or develop the foundation of a full design effort. This type of tailored approach allows us to fit seamlessly within, and provide added value, to any existing or new AECOM federal contract that is impacted by the federal mandate requirements."
In addition to addressing energy as a component of the larger SSIM planning process, AECOM has used SSIMe on the San Ysidro Land Port of Entry to comply with the GSA's P-100 design guide's life cycle assessment requirements while maintaining a fast track schedule. AECOM used SSIMe to validate the energy and cost performance of a potential Energy Savings Performance Contract (ESPC) at Fort Irwin in California, U.S.A. A SSIMe Stage 1 analysis was utilized at NASA's Ames campus in Moffett Field, California, U.S.A., to provide energy and carbon information for the 30-year master plan, and to identify potential areas of expansion to the planned energy upgrade program.
AECOM Principal of Building Engineering Alastair MacGregor, who leads the High Performance Buildings Group noted that "as a result of utilizing the SSIMe process, AECOM teams are able to undertake real-time gaming of energy conservation measures directly with clients, thus allowing for consensus to be achieved through a much more streamlined and client-engaged process. As a result, AECOM can provide conceptual energy information in a more cost-effective and timely fashion."
Controlling cost
PACES is an integrated PC-based system that prepares parametric cost estimates for new facility construction, renovation and site work. PACES uses pre-engineered model parameters and construction criteria to accurately predict construction costs with limited design information.
"This parametric approach differs from traditional cost estimating methods by allowing users to input a minimum amount of information to create a cost estimate with model default quantities based on similar projects and experienced architectural and engineering assumptions," explains Kirk Rabius, leader of capital and facilities planning for AECOM's Economics practice. Predefined and documented engineering relationships link the primary parameters to detailed design assumptions and associated engineering quantities.
AECOM used PACES to help the U.S. Air Force prepare an Air Education and Training Command (AETC) dormitory asset development plan. AECOM conducted room-by-room condition assessments for over 30 housing buildings at ten locations throughout the United States in less than two months. AECOM also developed cost estimates using PACES for nearly US$100 million in short-term and long-term asset renewal and replacement projects to address identified deficiencies over a 15-year period. The goal of this project was to lay the foundation for a command-wide and unified 2020 investment plan as a component of the overall USAF dormitory management program.
The dormitory asset plan project followed another AETC project that involved over 20 million square feet at 12 installations. Facility types included youth recreation centers, restaurants, cafes, snack bars, post offices, family housing units, dormitories, thrift shops, medical facilities, child care facilities, golf clubhouses and many other types of public, hospitality, medical, education and administration facilities. The effort combined field survey, electronic data collection, assessment, analysis, and interaction with stakeholders at each of the installations to create an optimal long-term plan focused on meeting future mission requirements, with cost estimates and rate-of-return analysis for each of the identified projects.
Jake Herson