sustainable design

Sustainable Design in Practice

The fundamental principles of sustainable design principles are frequently expanded to five categories (USGBC 2005, WBDG 2006):
• Site: optimize the potential of the building’s site.
• Water: reduce water use throughout building systems.
• Energy: reduce energy use throughout building systems.
• Materials: use environmentally preferable products.
• Environmental quality: provide optimal indoor conditions to minimize adverse effects on occupants’ health.

Select sustainable design programs incorporate operations and maintenance (O&M) practices into sustainable design considerations (GSA 2004). This is an important addition and demonstrates the significance of O&M to an organization managing facilities amounting to billions of dollars.

The cost for a sustainable building has long been considered a barrier for owners to pursue sustainability in their capital projects. However, the costs and financial benefits of green buildings (Kats et al 2003) reports that sustainable buildings have a cost premium of only 2%. However, this investment can be reasonably anticipated to return ten-fold over the life of the building through anticipated savings from reduced energy consumption, water use and waste. In addition, investing in systems that retain value as the facility ages reduces the risk associated with the initial investment.

Keys to Success

There are five keys to success in sustainable project delivery; early adoption of sustainability, evaluation of sustainability in regard to the business case, alignment of sustainable features to the intent of the building, early involvement of experienced individuals in sustainability, and alignment of team member goals and project goals
(Lapinski et al 2006). To successfully implement sustainable strategies throughout a project, structured communication and a view towards lifecycle analysis have proved to be key components. Using an integrated design process and clearly documenting owner specifications form the foundation for a successful project team.

The Integrated Design Process

Industry-wide challenges such as team formation, fragmentation of design disciplines, undefined roles and responsibilities, and misalignment of incentives are major problems to the project delivery process (Egan 1998, Kayshap et al 2003, Riley et al 2004, Magent 2006). The  integrated design process seeks to ease these challenges through the increased communication and collaboration between team members. However, the project team is limited to the information provided to them, which places great importance on the project request for proposals (RFP) and specifications. This places critical responsibilities on the owner’s representative to ensure that owner requirements, present and future, are communicated to the design team to develop the best
solution.
The integrated design process can be encapsulated by early participation in the project by everybody involved in the project’s design, discussing everything about each system’s design (Reed 2004). The increased communication among team members responsible for each building system provides for greater understanding of the interdependency of building systems. The increased collaboration aids the development of more precise design conditions, reducing the need for safety factors and over-design. Systems designed to the correct size perform more efficiently and more effectively, reducing energy costs and increasing occupant satisfaction.

Emphasis on the Lifecycle of Building Systems

Life cycle analysis guides the design team to focus on the entire use of a product or system, including its initial costs (materials, labor, transportation, etc.), maintenance costs, energy requirements and disposal costs (Arditi et al 1996, Asiedu & Gu 1997). Clearly, life cycle analysis, when implemented effectively, helps reduce the operating costs of the facility. However, assumptions regarding in-use conditions may be inaccurate, leading the design team to select a product or system that is not ideal for the application.

Building Commissioning

Commissioning is a key scope of work to include in the delivery of sustainable buildings. Commissioning seeks to check system design and installation to ensure design intent and design conditions are achieved (EERE 2004). Early in the project, the commissioning agent performs system design reviews, focusing on the ability of the system to meet the intent of the design (Ellis 2004). Later in the project, the commissioning agent focuses on the installation and operation of the system to meet the design intent – this is accomplished through metering and balancing the system. Upon completion, commissioning ensures systems operate to meet design conditions.