Interest in taller wood buildings utilizing cross laminated timber (CLT), nail laminated timber (NLT), and structural glued laminated timber (glulam) is growing rapidly in Canada and the United States. On the west coast, recently completed projects including the 97 foot tall, 6-story Wood Innovation and Design Center (WIDC) in Prince George, BC, the 180 foot tall, 18-story UBC Brock Commons Tallwood House in Vancouver, BC, and the upcoming 12-story Framework project in Portland, OR, have captured the attention of the international construction industry. Several other taller wood buildings are on the horizon and feasibility studies are currently being performed for mass timber buildings over 30 stories in height. Tall wood buildings have been a reality in Europe longer than North America, and there is much to learn from the European experience. However, conditions unique to the North American construction industry create many challenges for the design team in demonstrating the safety, durability, and economics of these buildings, all while forming public perception of wood at taller heights. Presented at the 15th Canadian Conference on Building Science and Technology.

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Tall Wood Building Enclosures
A Race to the Top
CCBST VANCOUVER, NOVEMBER 2017
BRIAN HUBBS, P.ENG – PRINCIPAL, SENIOR FAÇADE SPECIALIST

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Design Considerations for Tall Wood
Buildings

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Taller Wood Building Precedents – Europe,
Australia & North America
LCT One, Austria Forte, Melbourne WIDC, Prince George
T3, Minneapolis
Murray Grove, London
TREET, Norway
UBC Tall Wood House, Vancouver

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The Future of Tall Wood? – Concepts & Actual Projects
MGA
CEI Architecture
Terrace House – Shigeru Ban / RDH

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The Building Enclosure
Image Credit: MGA
- Wood Innovation
Design Centre
Structure

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Taller Wood Building Structures
 Fast
 Sensitive to moisture
 Greater movement
(shrinkage & drift)
 Fire code challenges
 Mixed steel, concrete
& wood materials
 Is not the same as stick-
built wood-frame and
also different from
high-rise steel or
concrete structures

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Potential Challenges with Mass Timber Buildings

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Building Enclosure Design Fundamentals
 Primary function of the Building
Enclosure/Façade: Separate the
exterior & interior environments
 Protect mass timber during
construction & in-service
 Serves functional and aesthetic &
purpose
 Controls heat, air, and moisture
transfer along with noise and fire
 Designed to accommodate
building movement, structural
loads, initial & seasonal wood
movement
 Key passive design element for an
sustainable, energy efficient
building

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Tall Versus Shorter Mass Timber Buildings
 Tall Wood Structures
 More repetitive, more exposed, difficult
access, need for more speed – ideal for
prefabricated facades
 Less focus on roof and more on walls for
weather protection
 Low to Mid-rise Wood Structures
 Easier access to walls from ground
 Greater focus on roof for weather
protection than walls
 Prefabrication of façade also possible
though less economies of scale

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Tall Wood Building Enclosures
 Need for Speed
 Erect and seal fast
 Protect wood structure
 Accommodating of
inclement weather
 Ensure Durability
 Robust materials –
high-rise appropriate
 Tolerant of movement
 Thermally efficient
 Non-combustible

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Façade Systems - Load Bearing vs Curtain-wall

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UBC Brock Commons, Tall Wood House
Façade Challenge

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UBC Brock Commons, Tall Wood House
Façade Challenge

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Initial Concerns & Questions from Project Team
 Vancouver = Temperate rainforest
 How to protect mass timber from
rain during construction in any
season
 Giant tarps?
 Temporary roof lifted by crane?
 Waterproof the floors?
 Enclose as fast a possible?
 Enclosure must keep up with pace of
structure
 How long can mass timber floors get
wet for? Best way to protect it?
 How to enclose & seal the walls
quickly and not be slowed by
inclement weather?

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UBC Brock Commons - Façade Design Criteria
Fast installation
– 1 floor/day &
water tight to
protect
structure Thermally
Efficient,
>R-16
effective walls
Inexpensive,
<$50/sqft
installed &
finished
Installed
without access
to exterior –
no sealing or
finishing
Pre-installed
cladding &
windows
Durable &
High-
performance
Resistant to
water & able
to install in
rain

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Precedents for Prefabrication of Tall Wood

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Precedents for Prefabrication of Tall Wood

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Precedents for Prefabrication of Tall Wood

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UBC Brock Commons- What Wasn’t Feasible

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Unitized Curtain Wall Option
Problem: Cost, Schedule, Energy

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Window-Wall Option
Problem: Schedule, Energy

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Small Panel Prefabrication Wall – Precedents
Problem: Schedule

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Orchard Commons

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Tall Wood Prefabrication Option – Large Panel
with Pre-installed Windows

26. Tall Wood Concept Panel

27. Tall Wood Concept Panel

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UBC Brock Commons - The 4 Panel Contenders!
Pre-Cast Concrete Sandwich Panels Steel Stud Framed Panels
Wood Stud framed or CLT Panels Aluminum Window-wall
Not thermally
efficient enough for
project nor met the
design intent, but
kept as contingency
and costed

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Prefabricated Panel Competition Mock-ups

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Performance Mockup
Proposed RDH (Similar Cost)
Proposed
Construction Team

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Laboratory Mockup & Physical Testing

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Centura – Factory Floor Prefabrication

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Site Installation – at Pace with Structure – 1 floors/day

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Field Testing and Commissioning

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Future of Wood High-Rise
Passive House vs Terrace House

46. 46Brian Hubbs, bch@rdh.com