What is Whole Building Design and Why is it Important?
Whole Building Design is a design process that views the building as a system, rather than a collection of components. The latter perspective limits significantly how sustainable a design can be, as it really only allows for a process of substituting “green” features for conventional ones.
On the other hand, viewing the building as a system allows full integration of decision making. Besides the fact that this approach gets better performance out of a building overall, it is also the best way to avoid unnecessary costs. National research indicates that a sustainable design approach should not add more than 2% to the cost of a building, and may incur none if done thoughtfully. Research also indicates that the sooner sustainability is introduced into a project, the more likely it can be achieved cost-effectively. This cost-control is directly attributable to using a systems approach to the design. Opportunities for combining functions and multiplying the benefits achieved from a single strategy are much more available with this approach.
|This CMU elevator shaft at the LEED Silver-rated Merrill Hall at the University of Washington, serves as a natural ventilation stack.|
How is it Accomplished?
What is the Benefit of Concrete in Whole Building Design?
Concrete is a versatile material that can be used to provide many sustainable building benefits by functioning as thermal mass, acoustical barrier, durable structure. Looking at ways to combine the functions concrete is performing for a building is a way to do more with less. For example, from a wholistic point of view, a structural shaft produced from concrete material (such as CMUs) might be viewed as ventilation shaft, a light well, and a means of controlling temperature. Besides providing integrated performance, this strategy saves money because it reduces the need for equipment.
Whole Building Design requires a commitment on the part of the owner and design team to an interdisciplinary approach. Check-ins along the design path and during construction at regular intervals assures follow-through to this commitment. Design and construction contracts should reflect the project’s commitment to whole building design.
Whole Building Design generally means investing in design activities that increase the opportunity for integrated solutions, with an eye to better performance and life cycle savings. Integrated design activities generally include an eco-charette, life-cycle analysis, and modeling, testing, and evaluation studies.
|Interdisciplinary teams use green design workshops, or eco-charrettes, to look at ways to integrate and optimize their design early in the process.|
Eco-Charettes are planning workshops that ideally occur early on in a project (no later than the schematic phase). They are the first step in an interdisciplinary design process and should include owner representatives, design consultants, and end users. The length of the workshop varies with project size, budget, and other factors; however the agenda should include time for education of the parties, goal setting, strategic brainstorming, and prioritization. There are now some software programs (for example Energy Scheming) that can be used at charettes to provide immediate feedback on energy saving concepts put forth at eco-charettes.
In addition, eco-charettes are a good opportunity to evaluate the project’s ability to meet green building standards. If the project is a LEED project (see more on LEED below), a preliminary LEED Scorecard can be developed. Typically, the results include a number of credits that are eliminated, a number of credits that should be explored, and a number of credits that should definitely be aimed for.
Life Cycle Cost Analysis
Typically, first cost is what designers and owners look at when analyzing whether to proceed with a specific strategy, sustainable or not. However, it is in the long period of operation that the given strategy will prove its worth. According to the Sustainable Building Technical Manual, operations and maintenance costs equal 6% of overall business costs, compared to only 2% for initial building costs (the large remainder is for personnel).
A Life Cycle Cost Analysis (LCCA) provides a much more accurate context for decision making. There are a variety of methods for doing this. The National Institute of Building Sciences describes LCCA in its Whole Building Design Guide.
The building life-cycle cost (BLCC) software from the National Institute of Standards and Technology provides economic analysis of capital investments, energy, and operating costs of buildings, systems, and components. The software includes the means to evaluate costs and benefits of energy conservation and complies with ASTM standards related to building economics and Federal Energy Management Program requirements. In addition the Pacific Northwest National Laboratory has developed Facility Energy Decision System – FEDS 5.0 which analyzes energy efficiency in single or multiple buildings. FEDS can determine the impact of energy efficiency retrofits on emissions of CO, CO2, NOx, SO2, hydrocarbons, and particulates.
By incorporating life-cycle costs into the design mix, more informed decisions can be made.
Modeling, Testing, Evaluation
An integrated design process assumes a number of building solutions will be considered and that some degree of analysis will take place to compare strategies and determine which ones are appropriate to achieve the desired performance. Modeling (simulation or physical) of daylight, energy use, water use, and air flow are methods that can be used to conduct this analysis. Costs vary with the complexity of the process used.
It is important to note that although modeling provides important design guidance, it is limited to providing projections. Testing or monitoring of conditions (pre/post) can be valuable learning tools to inform the current design as well as future projects. Post-occupancy evaluations POE are expected to become more important in the sustainable building world, as they will provide much needed feedback on how buildings actually perform.
LEED and Whole Building Design
The US Green Building Council (USGBC) has through consensus of its membership – primarily design and construction firms, government agencies, product suppliers, and environmental consultants – developed the Leadership in Energy and Environmental Design (LEED) Green Building Rating System. The USGBC hopes through LEED to “promote integrated, whole-building design practices.” As noted above, using the integrated design approach, higher levels of creativity are tapped, better performance can be achieved, and costs can be controlled – all worthy goals. Also, as noted above, concrete because of its versatility, can play an important role in achieving these results.
According to Martha VanGeem and Medgar Marceau, LEED-accredited professionals with Construction Technology Laboratories (CTL) Inc, as many as 21 of the minimum 26 points needed for LEED certification can be earned through the appropriate use of concrete. This assumes a concerted effort to look at the ways concrete can be used to build a greener building. Some of the attributes valued in LEED that concrete products can provide, and which relate to LEED credits include: optimizing energy performance, recycled content, recyclability, local manufacture, and durability.