Masonry Magazine December 1993 Page. 16
Unit pricing in the study reflects the total cost incurred by an owner commissioning an architect to design and solicit bids from general contractors.
Costs are based on 1993 pricing and include: architect/engineering fees, general requirements, general contractor overhead and profit, and subcontractor overhead and profit. Labor is based on prevailing wage rates.
Further assumptions were made in arriving at operating costs: HVAC costs were based on the respective U factors of the different wall types.
Maintenance costs for both types of curtain walls were based on cleaning interior and exterior glass four times a year and replacing broken panels as necessary. Maintenance costs for the four types of brick walls were based on cleaning and pointing the face brick after ten years of wear.
Maintenance costs for architectural precast concrete are based on sandblasting the face after ten years of wear. An additional cost for painting interior walls every three years was assigned to all four types of brick and architectural precast concrete walls.
Insurance was based on the cost of insuring a commercial or residential building against casualty loss for each wall type.
SUMMARY COMPARISON:
COMMERCIAL OR RESIDENTIAL (ABOVE SIX STORIES)
| % OVER WALL TYPE | INITIAL COST | 10 YR OPER COST | TOTAL COST | UTILITYBLOCK |
|---|---|---|---|---|
| A. Utility Brick/Block | $479,468 | $350,760 | $830,228 | 100% |
| B. Engineer Brick/Block | 599,400 | 370,240 | 969,640 | 125% |
| C. Face Brick/Metal Stud | 633,607 | 430,090 | 1,063,697 | 132% |
| D. Face Brick/Block | 741,090 | $389,730 | $1,130,820 | 154% |
| E. Architectural Precast Concrete | $804,600 | $461,760 | $1,266,360 | 167% |
| F. Curtain Wall/1" Glass | $861,008 | $804,020 | $1,665,028 | 179% |
| G. Curtain Wall/High Quality | $1,280,503 | $804,020 | $2,084,523 | 267% |
and operating costs for all four types of brick walls were less, in some instances less than half those for both types of glass curtain wall and architectural precast concrete exteriors. Overall, the utility brick/block backup combination proved least expensive.
Study Findings
The Building Evaluations study concluded overall that construction
GRANITE PROJECT HONORED
The accompanying table comparing construction and operating costs for a commercial or residential building above six-stories in New York typifies the study findings.
On average, and assigning a value of 100 percent to the utility brick/block backup wall exterior, for buildings under six-stories, the initial cost for engineer brick/block backup wall is 25 percent higher; the face brick/block backup wall 54 percent higher; face brick/metal stud 32 percent higher, architectural precast concrete 67 percent; the 1" insulated glass curtain wall 79 percent higher; and the high-quality curtain wall nearly 167 percent higher. Similar cost increases applied to buildings above six stories.
The study also reflects the considerably lower cost of brick facade due to material savings in comparison to the glass and precast facades. The same is true for operating costs. Higher HVAC costs are associated with glass due to its relatively lower energy efficiency compared to brick.
The accompanying tables provide more detailed results of the study. Table A illustrates an example of one of the study's detailed unit price report analyses and costs of face brick/
Continued on Page 36
THE BOSTON FIRM of Shepley, Bullfinch, Richardson and Abbott received an honor award in architecture for the design of the Smithsonian Institution's National Museum of African Art (pictured). The award was granted by the General Services Administration (GSA) for excellence in projects commissioned by the federal government. Cold Spring Granite Company supplied the 12,000 square feet of Sunset Red granite used in the project and Blake Construction of Washington D.C. did the masonry work.
16 MASONRY-NOVEMBER/DECEMBER, 1993