Using the Advanced Energy Design Guide to Support Integrated Project Delivery of Highly Energy Efficient Small to Medium Office Buildings
Many design practitioners believe that a collaborative design and construction team processes will lead to better decision-making, but improved relations alone do not necessarily mean increased energy efficiency. Along with the pursuit of deeper energy savings, Integrated Project Delivery (“IPD”) is one of the most intriguing current innovations in the building design industry. For designers interested in opportunities to explore both of these trends at the same time, a recent publication may hold the key.
Chapter 2 of the recently published Advanced Energy Design Guide for Small to Medium Office Buildings: Achieving 50% Energy Savings Toward a Net Zero Energy Building (“AEDG”), is a resource that begins to explain how to use IPD to achieve energy savings, by asking the right questions at the right time. The AEDG was developed by representatives of ASHRAE, AIA, IESNA, USGBC, and USDOE and is available free for download at http://www.ashrae.org/publications/page/aedg50pct. Previous guides in the AEDG series have been very technically focused, with extensive charts enumerating prescriptive values to govern design. To augment this approach, the Office 50% AEDG explores the interconnectivity of critical decisions across a number of disciplines.
Chapter 2 was written for a broad audience of stakeholders involved in the design process and begins by clarifying how greater efficiency and quality of design and construction is obtained through trust, early involvement of all, common goals, open communication and cooperation. An idealized design management guidance template is included to document Key Design Activities for Energy Efficiency. Detailed descriptions are provided, by project phase, of what issues should be considered by the team.
For example, during the crucial Project Kickoff phase, the AEDG recommends that an Owner’s Project Requirements document (OPR) be written to compile project goals. Alignment on both the goals and their relative importance is useful so that team members do not pursue divergent paths. Some suggested points for discussion are:
- Construction and Operating costs
- Frequency of use
- Target energy labels/ratings
- Payback period/ ROI thresholds
- Ownership/leasing arrangements
- Prioritization of requirements
- Funding requirements
During the Concept phase, the AEDG recommends completion of a series of holistic studies related to climate, site investigation, and building configuration, to creatively address:
- Site conditions
- Availability of natural resources
- Local material availability
- Access to transportation
- Environmental risks or opportunities
- Daylighting and natural ventilation potential
- Perimeter occupant comfort
The AEDG also recommends that teams, during Schematic Design, develop a preliminary energy model for a representative zone, on each face of the building, exploring the interplay of façade component performance; the amount and placement of glazing; and impacts upon annual operating costs, comfort, and first costs. At this time, most teams would also complete a preliminary project cost estimate; so it is a critical time to look beyond capital cost, to review opportunities to reduce operating expenses. A selection of Energy Conservation Measures (ECMs) should be analyzed, to support this effort. Typical comparative evaluation criteria include:
- Additional first costs
- Anticipated energy/maintenance savings
- Payback period/Return on Investment
- Energy and carbon emissions savings
- Additional savings, additional USGBC LEED points, utility incentives
- Range of light levels/temperatures throughout year
Armed with this information, teams will be prepared to enter Design Development, ready to evaluate design options using Life Cycle Cost Analysis (LCCA), a 20-to-25 year view of the building and its projected operating expense. The goal of this analysis is to determine where early investments will continue to reap savings for a decade or more after payback is achieved. It is often useful to complete LCCA early enough to offset the first-cost saving pressures of value engineering. As a final, project-specific collection of ECMs is determined, the design team can update its Basis of Design document (BOD) for the Commissioning Agent’s review, to ensure that the goals of the Owner’s Project Requirements (OPR) have been maintained.
During the Construction Documents phase, the AEDG recommends that a pre-construction review of constructability, on-site waste reduction, and material sourcing be conducted with the builders. Small changes to specifications or typical details, during this phase, are often negligible in cost but might easily result in a project with improved durability, reduced off-gassing, selection of the most appropriate building methods, and increased local industry engagement. At this point, the AEDG also strongly recommends a thorough review of control strategies, to ensure design intent clarity. A design with the best intentions can still fail miserably, regarding energy savings, if controls are implemented poorly. Lastly, during the Construction Documents phase, the AEDG recommends that the design team produce a user-friendly tenant education guide that contains a few key items such as:
- Introductory content explaining why energy efficiency is important.
- A “cartoon” type graphical representation of energy-efficiency features
- An estimate of energy savings compared to a familiar metric such as “equivalent to a certain number of single family homes”
- A “what you can do to help” section
As Construction begins, it is crucial that newly engaged team members be introduced to both the IPD ethos and the energy efficiency principles of the project, so that they can complete their project scope in compliance with these requirements. During this phase, the AEDG recommends that the commissioning agent and design team review submittals and only accept substitutions if equivalent energy performance is proven. The owner’s facilities team is often trained during this commissioning period, to better understand the critical maintenance activities that will lead to optimized energy savings throughout the life of the building.
Once aware of the synergies between IPD and energy efficient design, project team members interested in greater technical detail, can turn to Chapter 3 of the AEDG, which expands upon a variety of integrated design strategies, including discussion of building and site design features, more detailed information about the most effective energy conservation measures, and an in-depth discussion of multidisciplinary coordination issues.
Midway through the AEDG, Chapter 4 provides prescriptive performance values by component, and a summary of climate-based design considerations for the main United States climate zones. The tables in Chapter 4 are cross-referenced with Chapter 5’s “How-To” tips, where specific, detailed, design recommendations are provided at a component or system design level.
In summary, the new 50% Advanced Energy Design Guide compiles, in one 200 page document, a series of collaboration and technical recommendations that will help design team members, of all backgrounds, find the necessary details to support their common efforts to systematically achieve deep energy savings.