Green Renovation

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Q&A with Lee Davenport R.A., LEED AP BD+C. Lee specializes in Federal projects and has practiced architecture since 1984.

Q: With all the focus these days on green building and energy conservation do you set energy goals when beginning a project?

A: Yes! Many of my projects are LEED (Leadership in Energy & Environmental Design) and USGBC (US Green Building Council) Silver certified and I start by setting targets for a project’s energy and water savings before beginning design. For non LEED certified buildings, I will incorporate an energy analysis into the design early to ensure building envelope and lighting are going to meet or exceed energy code requirements anyway.

Q: What are your thoughts on the WSEC and the role it plays in your work / planning?

A: Washington State Energy Code is a very robust and thorough program that applies to all of our projects. Assuring our designs are meeting or exceeding the codes involves a complex process. I always take into account the budget and client’s needs when planning a project. One example would be the evaluation of indoor environmental quality by specifying materials that won’t off-gas. Off-gassing occurs when chemicals or VOCs (volatile organic compounds) evaporate into the air causing headaches, nausea or dizziness. Materials like paints and varnishes, cabinets and carpets can contain formaldehyde and cause off-gassing. We make sure the materials we specify are low to no-VOC. Additionally, we specify materials that have recycled content.

All of our projects with sustainable features are analyzed for life cycle costing. For instance, we can look at a green roof and evaluate the upfront cost of the feature versus how long it will take to get a payback from the energy savings of the feature. Not every client is able to afford the upfront costs required to earn a LEED Certification, but most projects can end up saving our clients 30 to 40% on energy usage. We also use a performance based approach during design development early on, so we can change variables if a client wants more glass than is specified in the code. We can creatively adjust by adding special glazing to the glass or increase the amount of insulation on the roof.

Q: Is early energy code analysis helpful when design begins?

A: Early energy code analysis is absolutely necessary in the beginning of design. We integrate sustainability in the beginning to avoid revising the design later and whereby costing the client more money. I always want to avoid the “Band-Aid” effect of changing plans if code officials reject the plans due to non-compliance. Complete energy efficiency and early integration provides the ability to meet both the code and the client’s requirements. Early energy planning also prevents the need to sacrifice special features or surprises when the budget won’t allow for last minute “fixes.”

Q: Do you utilize BIM (Building Information Modeling) to incorporate energy saving strategizes?

A: Yes. All of our drafting is done in Revit which allows us to export BIM information quickly and efficiently. Revit allows for easier comparison and changes to see what would happen if we took out half of the windows in the drawing or how doubling the insulation in the roof might affect the energy consumption in the building.

Q: How do you emphasize the importance of energy code compliance to clients and owners?

A: Many clients are already informed on the value and importance of saving energy through programs such as LEED. For the occasional unaware client, I like to start by sitting down with them and explaining the benefits of reducing energy usage like the financial benefits over time. For example, we are very good at incorporating materials and exploring daylighting options which will reduce lighting costs.

Q: What specific projects have you worked on recently and how did you assure building energy codes were addressed?

A: I recently worked on a major renovation for the Main Post Chapel at Joint Base Lewis-McChord (Note: The chapel was a BergerABAM project on which Helix was the architect) which involved extensive interior renovations, including a new mechanical system for cooling, which the building did not have previously. Early on in the project, we reviewed the energy and sustainable design standards that the project would need to meet. We discussed the criteria and sustainable design options with the Owner as part of a design “charrette,” which is an interactive meeting in which design options are discussed with all parties concerned in the project to solicit input and enable decision making.

Another example of a recent project is the design of major renovation work to four aircraft maintenance hangars at Joint Base Lewis-McChord. The projects involved an almost total replacement of the exterior “skin” of the buildings, including all siding, roofing, insulation and windows. The oldest building is historic, and had large areas of single pane windows and little insulation in the roof or walls. At the beginning of the project, we reviewed the energy and sustainable design criteria and requirements that would be applied to these buildings. Our findings, including the proposed solutions and preliminary cost estimates, were shared with the Owner early on and the design team was able to determine that the Energy Use Intensity (EUI) of the renovated building would be approximately 56.5 kBtu/sq. ft, below the calculated target of 58 kBtu/sq. ft. required. Estimated energy use is calculated to be 36% less than a standard building.

Q: What is the biggest challenge and/or reward of these projects in respect to building energy codes?

The Main Post Chapel project posed some interesting challenges. It is a historic building located in the center of Fort Lewis adjacent to the parade grounds. In order to preserve the exterior appearance of the Chapel as much as possible, the design team decided to use a ground source heat pump to cool the building. This highly efficient system incorporates underground geothermal pipes below the lawn area of the chapel to dissipate heat from the building and avoid any mechanical equipment above the ground, which would present aesthetic and noise problems. The exterior windows were another example: In order to preserve the existing exterior windows, some of which were very large, the design added high quality “storm” windows to the interior side of the existing to reduce heat loss. These interior windows incorporated operable sash so that users could open the windows if desired for outside ventilation, and were matched to the existing windows so that they would be unnoticeable.

One of the challenges with the Aircraft Maintenance Hangars was to upgrade the exterior building envelope to meet current codes and standards within the overall budget. Options were evaluated that included installing new siding over the top of the existing siding. However, we felt that to achieve an air tight construction and provide continuous thermal insulation, which are the most efficient means of reducing heat loss, the existing walls should be removed down to the framing, and include new sheathing, insulation and siding to ensure the highest level of quality control. Some of the windows in the office and shop spaces were reduced, since they provided too much heat gain during sunny weather, as well as heat loss in cold weather. The remaining windows were replaced and upgraded with windows of significantly higher energy efficiency. Large window areas were also replaced in the high bay areas with insulated translucent panels, significantly reducing heat loss/gain while still allowing a large amount of natural light into the main hangar bays.