All-wood Podiums in Mid-rise Construction

Karyn Beebe, PE, LEED AP

The Wood Products Council is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request. This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.

Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

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© The Wood Products Council 2012

Learning Objectives

At the end of this program, participants will have:

1.  Participants will analyze the code study including the opportunities and challenges for

wood use in this project and be able use that knowledge to specify this type of system

in the future.

2.  Attendees will learn the motivational drivers associated with the use of wood for this

project and why they may consider it on future projects vs. typically specified systems

3.  Participants will discover the structural challenges associated with a wood podium as

designed in this project and gain a better understanding of the collaboration necessary

with the structural engineer.

4.  Participants will understand how the building was designed for durability and longevity

using non-traditional systems and methods.

OUTLINE:

    

OUTLINE:

    

Podium Construction Defined

 Traditional Podium Construction

 Wood Podium Construction

Podium Construction Defined

History Wood Podiums OUTLINE:

    

 

 

 

 

 

 

  

 

 

 

 

  

 

 

 

 

  

 

 

 

 

  

 

  

 

 

Structural Specifications   Light-framed shear walls all levels   Wood Podium: Engineered Wood System

  Wood Structural Panels with gypcrete topping   I-joists   Glulaminated Beams (Glulams)

Structural Components

Structural Components

Light-framed shear walls   Superstructure

  Shear wall design methods   Architectural Gingerbread

Light-framed shear walls   Wood Podium

  Focus on Continuity   Detailing

Structural Components

Engineered Wood System   Wood Structural Panels

  Oriented Strand Board (OSB)   Plywood for balconies

  I-joists and Sawn Lumber

Structural Components Glulam Beams

  2 Stress Classes Bending Stress, Modulus of

Elasticity 24F-1.8E (2400 psi, 1.8x106 psi) 30F-2.1E LVL (3000 psi, 2.1x106

psi)

  Variety Sizes 5-1/8 inches to 12-1/4 inches wide 10-3/4 inches to 45 inches deep

Structural Components

LVL Laminations

Structural Components

High Strength Composite (HSC) Beams

  Hybrid Glulam with LVL Outer Laminations

  Full length with no finger joints required

  LVL has greater tensile strength compared to lumber

  30F-2.1E stress level achieved

  Direct substitute for many SCL products

LVL Laminations

Structural Components

Structural Steel   Steel Columns & Connections

  Price Steel Beams > Glulams

OUTLINE:

    

Heights and Areas

What factors into determining allowable heights and areas?

 

 

 

 

 

 

Heights and Areas

  

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Considering a Conventional Code Podium Will the parking work?

509.7 Open parking below Group R Height and area above the open parking garage per section 503; height measured from grade plane including both the garage and the building above the garage. Garage area / height per 406.3

Enclosed Garages: 406.4 Height and area as per table 503 as modified by sections 504, 506, and 507

Type V is OK for S2 Occupancy per table 503

For enclosed garage: Ventilation must be provided per Mechanical Code

Parking Garage is OK in Type VA construction IF it is enclosed

Enclosed Parking Garage

Ventillation Systems required for Enclosed Garages   Mech Code: 403.8 Exhaust Ventilation for Enclosed Parking Garages.

Exhaust airflow for enclosed parking garages shall be provided in accordance with the requirements in Table 4-4 and this Section. Exhaust makeup air shall be permitted to be any combination of outdoor air or transfer air.

  403.8.2 Alternative Exhaust Ventilation for Enclosed Parking Garages. Mechanical ventilation systems used for enclosed parking garages shall be permitted to operate intermittently where the system is arranged to operate automatically upon detection of vehicle operation or the presence of occupants by approved automatic detection devices.

  Part natural and part mechanical ventilation permitted by code   Final result: 10,000 cfm system cost 10K

Table 4-4 Parking garages 0.75 cfm / sq ft

Code Area Analysis

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Area AnalysisOccupancy Areas

Level One OccupancyAREAS

Gross SqFt

AREA subtotals

SqFt OLF Net O

r Gro

ss Area adjusted for

Net Occupancy Calculation

Occupant Load A M B S2 R

area subtotal check

Retail/Restaurant/Office Restaurant Seating A2 2209 15 N 2102 140.1 2209 Restaurant kitchen A2 479 200 G 2.4 479 Restaurant service A2 n.o. 496 496 Retail A M 4690 30 G 156.3 4690 Micro Retail B M 461 30 G 15.4 461 Service/Toilets M. 502 30 G 16.7 502 Subtotal 8837 8837

Residential Admin Area Lobby B 971 100 G 9.7 971 Office B 191 100 G 1.9 191 Multipurpose Room A-2 1631 15 N 1536 102.4 1631 Class room A-2 686 20 N 641 32.1 686 Refreshment Center B n.o. 205 200 G 1.0 205 Stair/Elev B n.o. 589 100 G 5.9 589 Service/Hallways/Toilets B n.o. 1042 300 G 3.5 1042 Reception B 204 100 G 2.0 204 Subtotal 5519 5519

Building Foot Print Retail/Resturant/Offfice & Residential Admin Area 14356

Parking Covered S2 22200 200 G 111.0 22200 22200 Open Air S2 2433 Subtotal 24633

Planters & Setbacks 1464

Lot Coverage (openair parking+landscape) 90%

Site Area 40453Total Occupant Load level one all spaces concurrent 600.5Acc: accessory use, not a concurrent occupancyN/O: Not occupied independent of related spaces

 

 

 

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Code Check Resources

Design Challenges & Solutions Durability:

  Protected building envelope   Different approaches

 Oceano  Galt

Exposed Conditions

Design Challenges & Solutions

  Preservative treatment   Naturally durable wood species   Alaskan

Yellow Cedar   Port Orford

Cedar

Durability:

Top Chord & Webs are DF Bottom Chord AYC

Two accepted fire rating methods recognized in the U.S.  IBC Empirical Method  NDS Mechanics Based Model

FRT

Design Challenges & Solutions Calculating Fire Resistance of Glulam Beams and

Columns, Technical Note Y245

Design Challenges & Solutions

Horyu-ji temple, Ikaruga, Nara Prefecture, Japan, (c. 711) Urnes stave church , Sogn og Fjordane County, Norway (c. 1150) Government Buildings Historic Reserve in Wellington, NZ (c. 1876)

Design Challenges & Solutions Communication:

  Project team   Subconsultants   Single Engineering Firm

  BIM  Glulam Manufacturers   Emphasis on Stacking

Design Challenges & Solutions Field Modifications:

  BIM   Hole cutting  Field Notching and Drilling of Glulam (APA Form S560)

OUTLINE:

    

Benefits Enhanced constructability:

  Fewer trades on job   Less mobilization time   Fewer construction delays

Benefits Enhanced constructability:

  Improved framing efficiency   Large pool experienced and competitive labor   Easier field modifications

Benefits Structural:

  Decreased mass for lateral design   Continuity of lateral system   Fewer design team members

Benefits Improved sustainability:

 Wood as a building material   LEED-HMR Silver (Oceano)   LCA

Galt Place is a great example of Smart Growth

  Mixed Use   Infill and Urban   Encourages

transportation choice - car, bus, walk, bicycle

  High in Resource Efficiency   low energy and land use   supports existing

infrastructure   Quality Design that

creates a sense of place

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Jb1.wmv

 

 

 

Galt Tracy Sacramento Elk Grove Stockton

Galt Place

Tracy Place Globe Mills

Waterman Square

Hotel Stockton

Loan per Unit $31,250 $88,000 $108,200 $89,000 $61,900

Number of Units 81 50 147 84 156

Total Loan

$2,500,000 $

4,400,000

$15,905,400

$7,476,000 $9,656,400

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Source Amount

Partnership Equity $ 13.4

Mortgage 1st TD $ 3.4 City RDA Loan 2nd TD $ 2.5

Deferred Profit $ 0.8 $ 20.1

Resources  APA Case Study, Form No. N110  www.apawood.org  www.woodworks.org

Questions?

This concludes The American Institute of Architects Continuing Education Systems Course

Karyn Beebe, PE, LEED AP APA karyn.beebe@apawood.org