Page 75 - Designing for Zero Carbon - Case Studies of All-Electric Buildings

Building Envelope
To provide the best sun control design and glare-free daylighting, as well as for simplicity of structure, the building was shaped into an elongated rectangle with the long sides facing south and north. Most of the programmed spaces were either small doctor offices with only occasional occupancy or larger public spaces like waiting areas. The offices are concentrated along the south side, where the sun control could be designed to provide shading without the intervention of the occupant. Likewise, the waiting areas are gathered along the north side, where the diffuse daylight provides abundant glare-free lighting without the need for electric lighting. This plan organization was dubbed “architectural zoning” by the design team.
For the solid walls, the cladding selected was an interlocking insulated metal panel3. Kaiser typically requires cement plaster exterior finish for cost reasons, but this product was specified because of the energy saved by eliminating the thermal bridging that occurs at the metal stud framing. The total R-value of this well-insulated opaque wall is R = 35. The rigid roof insulation installed under the “cool roof” membrane has an R-value equal to R = 15.
2”
R = 14
6”
R = 20
For the minimally-sized glazed areas on the elevations receiving direct sun, electrochromic glass4 is used. This product has a coating that darkens the tint of the glass dynamically depend- ing on the incident light spectrum. When this glazing is used, expensive sun-shading devices are not needed for fine-tuned solar control of the small glazed openings, thus offsetting the higher cost of this product. For the substantial glazed areas of the north elevation, insulated glass with high visible light transmission (VLT) was used for the desired daylighting.
3 Designwall 2000 Architectural Wall Panel. See: https://www.kingspan.com/us/en-us/product- groups/architectural-panel-facade-systems/benchmark-architectural-wall-panels/design- wall-2000
4 Dynamic tinting insulated glass by Crystalite, http://crystaliteinc.com/pages/products/view- glass/. See also “Case Study No. 9, Speculative Office Building at 435 Indio Way”, Zero Net Energy Case Study Buildings Volume 2, April (2016).
Designing for Zero Carbon: Volume 1
(Below) Electrochromic glass is used on south, east and west elevations for sun con- trol. (Photo: Marco Zecchin)
KAISER MEDICAL OFFICE BUILDING CASE STUDY NO. 3
(Opposite Page) The glazed openings differ for the north facade (Top), which empha- sizes daylighting, and the south facade (Bottom) , which emphasizes solar control. See discussion.
(Photos: Marco Zecchin)
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