Sustainable Design What’s the Bottom Line? Presented by:
Tom Pientka, President & Owner Ken Pientka, Chief Operating Officer PLANNING Design Build, Inc. Madison, Wisconsin
Today’s Presentation Objectives •
Compare and evaluate the first cost differences between two nearly identical office buildings. The first being a well designed energy efficient office building and the second office building designed to achieve Gold certification under USGBC’s LEED™ Program – we will call this the Concept Building.
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Understand the cost differences on several of the main building systems.
PLANNING’S Motives •
Recognition that sustainable design is the coming trend.
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PLANNING had limited knowledge in sustainable design topics & LEED™
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Our research indicated that there was limited hard data about actual cost premiums for sustainable buildings.
PLANNING Design Build, Inc. Company Overview •
A design-led, design-build general contractor consisting of Architects, Engineers, Interior Designers, Estimators, Field Superintendents, Project Management and Quality Control.
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Our company structure uniquely qualifies us to design holistically . . . a key element for successful sustainable design.
Tomotherapy vs. Concept Building TomoTherapy Headquarters
Concept Building
TomoTherapy TomoTherapy is a medical technology company that has developed a revolutionary method to deliver radiation treatment for cancer. The TomoTherapy Hi·Art System delivers radiotherapy which conforms to the size, shape, and location of the patient's tumor, minimizing damage to healthy tissue surrounding the tumor.
Site Plan
Building Comparison Overview
Size (sq. ft) Schedule
TomoTherapy Headquarters
Concept Building
66,206
54,687
Construction Completed June, 2002
Competitively Bid January, 2003
LEED Scoring
11 points / 26 points
45 points (Gold)
HVAC System
Overhead VAV 52% energy savings vs. 90.1
Raised Floor 54% energy cost savings vs. 90.1
Storm Water Management
Modest use of low islands, overland swale and roof garden
Maximized use of free green area on site to control runoff and 75% green roof
Building Comparison Overview (cont.) TomoTherapy Headquarters
Concept Building
Glazing
High performance glass optimally selected for each orientation
High performance glass optimally selected for each orientation
Lighting
1.5 w/sf – Indirect T5 HO lighting with dimming ballasts and std. Efficiency fixtures (88% efficiency)
.75 w/sf Indirect, t5 HO lighting with dimming ballasts and high efficiency fixtures (93.8%)
Materials and Resources
Modest use of recycled and renewable materials
Maximized use of locally sourced rapidly renewable materials and high recycled content
Water Use
Met the 1992 Energy Policy Act guidelines
Reduce base building water use by 20% vs. 1992 Energy Policy Act guidelines
Concept Building Process •
Overall Goal – To create a ‘twin’ sustainable building using holistic design principles.
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Formed an interdisciplinary team of designers, construction staff, specialty consultants, contractors and suppliers.
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Developed committees that mirrored LEED™ categories
Project Costs •
TomoTherapy – Designed and built during the period of 10/01 through 6/02. Project costs based on total actual costs and include DB contractor fees and profit.
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Concept Building – Fully developed drawings. Project was competitively bid by subcontractors in January 2003.
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Project costs for TomoTherapy were adjusted to normalize costs with Concept Building and to remove variables such as changes in building codes and site conditions
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Concept Building includes commissioning costs.
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No cost adjustments for inflation.
TM
LEED
Scorecard TomoTherapy
Sustainable Site
4
TomoTherapy Certified 4
Concept Building
Water Efficiency
0
3
4
Energy & Atmosphere
5
9
12
Materials & Resources
2
3
5
IEQ
0
6
13
Innovation & Design Process
0
1
0
Total
11
26
45
11
Overall Cost Comparison
Total Cost (Shell & Buildout)
Cost/SF (Total) (Shell)
TomoTherapy
TomoTherapy Certified
Concept Building
$ 5,018,000
$ 5,100,000
$5,649,000
$91.75 $ 73.91
$93.20
$103.30 $ 83.81
Sustainable Sites Objective: Minimize storm water impacts – Retain all storm water on site for a 20 year storm event. TomoTherapy Technique Storm Sewer Piping
Concept Building
Cost
Technique $ 51,000
Cost
StormCeptor Underground Cistern Depressed Parking Islands
$ 52,000
Asphalt Paving
$ 2,600
Pervious Paving substituted for Asphalt in loading dock (2200 sf)
$ 13,900
Turf Grass
$ 5,000
Rain Gardens
$ 37,000
Ballasted Rubber Membrane Roof
$ 53,000
Green Roof
TOTAL
$ 111,600
TOTAL
$ 129,000 ($9.36/sf of roof area) $ 231,900
Sustainable Sites Green Roof Tomotherapy Rubber Roof System
Concept Building $ 53,000
Torch applied modified bitumen roof system
$ 82,500
Roof & soil vegetation (6’ depth)
$ 39,000
Additional Roof Steel TOTALS
$ 7,500 $ 53,000
$ 129,000 ($9.36 / roof sf)
Roof Rain Garden Analysis • • •
Minimal cooling load impact Roof rain garden cost/sf on low end of published data Consider elimination of roof garden as other storm water management measures are in place. Roof garden not cost justified on a Life Cycle Cost basis.
Materials & Resources Framing System TomoTherapy
Concept Building
Comment
Building Frame
Structural Steel
Structural Steel
Larger bay sizes in Concept Bldg. w/joist floor system – fewer columns
Floor System
Precast Plank w/concrete topping
Steel joists w/metal decking and concrete topping
Plank has limited economical spans in comparison to joists. - Joist system has less dead load - Concrete used in concept building deck contains recycled fly ash
Roof System
Steel Joists
Steel Joists
Additional dead load from green roof had minimal cost impact. More economical bay size resulted in lower total costs.
Total Framing Cost/sf Foundations & Footings Concrete
$ 7.92
$ 6.44
$ 81,000 Less
$ 76,000 $ 1.39/sf
$ 56,680 $1.04/sf
$ 20,000 Less
Materials & Resources Recycled & Recyclable Materials •
Bar joist framing & concrete deck – Cost savings vs. precast and increase in recycled materials
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Changed specifications to require use of fly ash & blast furnace slag – no cost increase
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100% recycled gypsum wall board – no cost increase
Materials & Resources Recycled & Recyclable Materials (Continued) •
Used recycled acoustical tile (70% recycled paper) – no cost increase, most tile is recycled.
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Recycled ceramic tile – big cost premium (approximately 2X) – did not use
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Cotton insulation not available to substitute for fiberglass
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Used carpet with 31% recycled content - No cost increase
Materials & Resources Rapidly Renewable Material •
Used bamboo to replace cherry flooring. Bamboo saves 60% vs. Cherry.
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Used Cork Flooring ($11.55/sf) in lieu of VCT ($1.50/sf). ($9,000 premium)
Energy & Atmosphere Low Emitting Materials •
Adhesives & Sealants – specified LEED™ criteria
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Paintings & Coatings – selected products with zero VOCs (no cost increase)
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Carpeting – met Carpet & Rug Institute guidelines while maintaining recycled & recyclable goals. Used carpet tiles throughout – raised floor.
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Composite Woods – specified formaldehyde-free MDF for cabinets & case work.
Energy & Atmosphere Lighting •
Optimized design by integrating glazing selections, 10’ ceiling heights, window placement, office layout and fixture selection
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Used indirect lighting system with T5 high output lamps, high efficiency fixtures (93.8%), daylight sensors and dimming ballasts
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Fixtures mounted 3’ below ceiling 20’ on center
Energy & Atmosphere Lighting (Continued) •
Lighting load of .5W/sf in open areas and .75w/sf overall – Tomotherapy – 1.5w/sf – Reduced cooling load by 12 tons
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Site lighting – 1242 w/acre (.03w/sf) $ 25,000 premium vs. TomoTherapy to achieve 20% load reduction. (not cost effective)
Energy & Atmosphere HVAC •
Raised floor distribution system
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Sealed combustion boiler (88%)
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Self-contained packaged units – Scroll compressor .9 kw/ton – VFD on air handler
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VFDs on cooling tower fans, hot water pumps & energy recovery unit.
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Tate Access Flooring System
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DDC Control System
Energy & Atmosphere HVAC TomoTherapy I Overhead VAV w/Heat Recovery
Concept Building Raised Floor System
HVAC System
$ 538,000
$ 623,000
DDC Controls
$ 54,000
$ 88,000
Electrical System
$ 362,000
$ 386,000
Difference = $143,000 ($2.60/sf)
Energy & Atmosphere HVAC System Analysis •
Peak cooling load of 100 tons (550 sf/ton) – Green Roof had minimal impact on peak load – Reduced cooling loads from building overhangs • 1.8% for 2’ overhang • 5.2% for 4’ overhang.
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Purchasing a packaged unit ducted into floor saved a total of $48,000 vs. custom AHU, but cost 1 point due to use of HCFC. 60 sf/floor of rentable space would also be lost. (Annual value of $2,700/yr)
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Raised floor HVAC pricing includes humidifier. ($25,000)
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Electrical system cost premium driven by site lighting costs. Minimal impact from raised floor.
Energy & Atmosphere HVAC - Raised Floor System Costs Analysis •
HVAC System + $ 119,000
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Access Flooring System + $ 390,000 – Carpet tiles sized to fit raised floor adds additional cost +/- $1/sf
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Total cost premium of $ 533K + carpet tiles must be offset by: – Increases in employee productivity – Reduced churn costs estimated at $ 1500/employee/year – Minimal energy savings
Design Adjustments Cost Adjustment
$ Change
LEED™ Scoring
Replace Raised Floor System w/Overhead VAV (Includes replacing access floor system)
- $ 512,000
- 1 point
Eliminate building height reduction savings by eliminating raised floor
+ $ 33,000
0
Replace green roof with silver reflective roof
- $ 67,000
0
Add back savings from change in building frame
+ $ 101,000
0
True up for change in private office count
+ $ 41,000
0
TOTAL
$ - 404,000
- 1 point
Cost Summary After Design Adjustments •
Original Cost Difference
$ 631,000
($ 5.649 M vs. $ 5.01 M)
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Cost Adjustments
-$ 404,000
(from previous slide)
Cost Increase to achieve LEED™ Gold rating
$ 227,000 ($ 4.15 / sf)
Conclusions •
A LEED™ Gold building can be constructed for about +/- $4.15/sf additional vs. the TomoTherapy building.
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Raised floor technology was new to our contractors (HVAC & Electrical) and may have affected pricing.
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Integrated / Holistic Design combined with access to accurate pricing is essential to optimize design yielding the best combination of performance, sustainability and cost.
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Time required for design burden to document and perform LEED™calculations is substantial and may be a barrier to applying for certification.
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Sustainable buildings are affordable. It is the right thing to do. Our role as professionals is to make it happen!
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