Mass timber continues to be a hot topic of discussion within the development industry in British Columbia. The International Building Code now allows for mass timber to be used for buildings up to 18 storeys. The change allows developers to consider it for residential multi-family projects and prompts one big question: “What will it cost to build my high-rise project with mass timber in our market?”
The team that developed this report represents an independent team of architects, structural engineers, quantity surveyors, and a general contractor. Consultants from fire, building code, and acoustic industries also provided expertise to the study. In late Fall 2020, we formed an industry group in Vancouver to answer this question with an exclusive focus on the local market. We identified a need for a significant shift in the local industry’s building philosophy when using mass timber as a structural material.
Our goal was to assess the viability of mass timber for this product type in British Columbia by comparing the cost, construction methods, and schedules of a typical concrete high-rise in Vancouver to those for the same building using mass timber as the principal structural material. To undertake the study, the group created virtual models of the base building and conceptual models for side-by-side detailed comparisons.
While gaining in popularity, building a high-rise with engineered mass timber remains an unconventional method in British Columbia. To support the industry, we wanted to fill in gaps in data to better understand and help solve the challenges of working with new materials and techniques needed for mass timber construction at scale.
This study presents what we learned about cost, schedule, and code implications as well as methodology efficiencies. It must be noted that the study took place over a period in Q2 and Q3 of 2021 when lumber and steel prices – two of the principal materials – experienced high volatility in supply and record increases in price.
Since every building project and market is unique, the report makes no claims concerning specific cost or time frame. Rather, it identifies what to consider in creating a reliable framework for optimizing costs and schedules while meeting code requirements when building residential high-rise mass timber buildings.
From record-breaking timber towers to innovative examples of adaptive reuse, mass timber construction is on the rise. Stay current with Think Wood and WoodWorks’ newly updated, must-have Volume 2 of the popular Mass Timber Design Manual.
Volume 2 features updated free and interactive resources to guide architects, developers, engineers, and anyone working on a mass timber project.
This manual is helpful for experts and novices alike. Whether you’re new to mass timber or an early adopter you’ll benefit from its comprehensive summary of the most up to date resources on topics from mass timber products and applications to tall wood construction and sustainability.
The manual’s content includes WoodWorks technical papers, Think Wood continuing education articles, case studies, expert Q&As, technical guides and other helpful tools. Click through to view each individual resource or download the master resource folder for all files in one handy location. For your convenience, this book will be updated regularly as mass timber product development and the market are quickly evolving.
Since the publication of the first edition of this guide, substantial regulatory changes have been implemented in the 2020 edition of the National Building Code of Canada: the addition of encapsulated mass timber construction up to 12 storeys, and the early adoption of the related provisions by several provinces are the most notable ones. The 2022 edition of this guide brings together, under one cover, the experience gained from recently built tall wood projects, highlights from the most recent building codes and standards, and research findings to help achieve the best environmental, structural, fire, and durability performance of mass timber products and systems, including their health benefits. The approaches to maximizing the benefits of prefabrication and building information modelling, which collectively result in fast, clean, and quiet project delivery, are discussed. Methods for addressing limitations controlled by fire requirements (through an Alternative Solution) or seismic requirements (through a hybrid solution using an Acceptable Solution in steel or concrete) are included. How best to build with mass timber to meet the higher performance requirements of the Energy Step Codes is also discussed. What makes building in wood a positive contribution toward tackling climate change is discussed so that design teams, in collaboration with building owners, can take the steps necessary to meet either regulatory or market requirements.
Buildings and the construction sector together account for about 39% of the global energy-related CO2 emissions. Recent building designs are introducing promising new mass timber products that have the capacity to partially replace concrete and steel in traditional buildings. The inherently lower environmental impacts of engineered wood products for construction are seen as one of the key strategies to mitigate climate change through their increased use in the construction sector. This chapter synthesizes the estimated carbon benefits of using engineered wood products and mass timber in the construction sector based on insights obtained from recent Life Cycle Assessment studies in the topic area of reduced carbon emissions and carbon sequestration/storage.
This paper is intended for developers and owners seeking to purchase insurance for mass timber buildings, for design/construction teams looking to make their designs and installation processes more insurable, and for insurance industry professionals looking to alleviate their concerns about safety and performance.
For developers, owners and design/construction teams, it provides an overview of the insurance industry, including its history, what affects premiums, how risks are analyzed, and how project teams can navigate coverage for mass timber buildings. Insurance in general can seem like a mystery—what determines premium fluctuations, impacts of a strong vs. weak economy, and the varying roles of brokers, agents and underwriters. This paper will explain all of those aspects, focusing on the unique considerations of mass timber projects and steps that can be taken to make these buildings more insurable.
For insurance brokers, underwriters and others in the industry, this paper provides an introduction to mass timber, including its growing use, code recognition and common project typologies. It also covers available information on fire performance and post-fire remediation, moisture impacts on building longevity, and items to watch for when reviewing specific projects.
These Joint Professional Practice Guidelines – Encapsulated Mass Timber Construction Up to 12 Storeys were jointly prepared by the Architectural Institute of British Columbia (AIBC) and Engineers and Geoscientists British Columbia.
The AIBC and Engineers and Geoscientists BC regulate and govern the professions of architecture, engineering, and geoscience under the Architects Act and the Professional Governance Act. The AIBC and Engineers and Geoscientists BC each have a regulatory mandate to protect the public interest, which is met in part by setting and maintaining appropriate academic, experience, and professional practice standards.
Engineering Professionals are required per Section 7.3.1 of the Bylaws - Professional Governance Act to have regard for applicable standards, policies, plans, and practices established by the government or by Engineers and Geoscientists BC, including professional practice guidelines. For Engineering Professionals, these professional practice guidelines clarify the expectations for professional practice, conduct, and competence when providing engineering services for EMTC buildings. For Architects, these guidelines provide important information and identify issues to be considered when providing architectural services for EMTC buildings. These guidelines deal with the performance of specific activities in a manner such that Architects and Engineering Professionals can meet their professional obligations under the Architects Act and the Professional Governance Act.
These guidelines were developed in response to new classifications of building size and construction relative to occupancy introduced in the 2018 British Columbia Building Code (BCBC), under Division B, Article 3.2.2.48EMTC. Group C, up to 12 storeys, Sprinklered, and Article 3.2.2.57EMTC. Group D, up to 12 storeys, Sprinklered. These new classifications were introduced in Revision 2 of the 2018 BCBC on December 12, 2019 and in Amendment 12715 of the 2019 Vancouver Building By-law (VBBL) on July 1, 2020. Additionally, provisions related to Encapsulated Mass Timber Construction (EMTC) were introduced in Revision 1 of the 2018 British Columbia Fire Code (BCFC) on December 12, 2019.
These guidelines were first published in 2021 to provide guidance on architectural and engineering considerations relating to these significant changes to the 2018 BCBC, the 2019 VBBL, and the 2018 BCFC. For Engineering Professionals, these guidelines are intended to clarify the expectations of professional practice, conduct, and competence when Engineering Professionals are engaged on an EMTC building. For Architects, these guidelines inform and support relevant competency standards of practice to be met when Architects are engaged on an EMTC building.
As with all building and construction types, the EMTC-specific code provisions prescribe minimum requirements that must be met. The majority of EMTC of 7 to 12 storeys are considered High Buildings, and as such are subject to the BCBC, Subsection 3.2.6. Additional Requirements for High Buildings.
The development of this primer commenced shortly after the 2018 launch of the Mass Timber Institute (MTI) centered at the University of Toronto. Funding for this publication was generously provided by the Ontario Ministry of Natural Resources and Forestry. Although numerous jurisdictions have established design guides for tall mass timber buildings, architects and engineers often do not have access to the specialized building science knowledge required to deliver well performing mass timber buildings. MTI worked collaboratively with industry, design professionals, academia, researchers and code experts to develop the scope and content of this mass timber building science primer. Although provincially funded, the broader Canadian context underlying this publication was viewed as the most appropriate means of advancing Ontario’s nascent mass timber building industry. This publication also extends beyond Canada and is based on universally applicable principles of building science and how these principles may be used anywhere in all aspects of mass timber building technology. Specifically, these guidelines were developed to guide stakeholders in selecting and implementing appropriate building science practices and protocols to ensure the acceptable life cycle performance of mass timber buildings. It is essential that each representative stakeholder, developer/owner, architect/engineer, supplier, constructor, wood erector, building official, insurer, and facility manager, understand these principles and how to apply them during the design, procurement, construction and in-service phases before embarking on a mass timber building project.
When mass timber building technology has enjoyed the same degree of penetration as steel and concrete, this primer will be long outdated and its constituent concepts will have been baked into the training and education of design professionals and all those who fabricate, construct, maintain and manage mass timber buildings.
One of the most important reasons this publication was developed was to identify gaps in building science knowledge related to mass timber buildings and hopefully to address these gaps with appropriate research, development and demonstration programs. The mass timber building industry in Canada is still a collection of seedlings that continue to grow and as such they deserve the stewardship of the best available building science knowledge to sustain them until such time as they become a forest that can fend for itself.
This manual is helpful for experts and novices alike. Whether you’re new to mass timber or an early adopter you’ll benefit from its comprehensive summary of the most up to date resources on topics from mass timber products and applications to tall wood construction and sustainability.
The manual’s content includes WoodWorks technical papers, Think Wood continuing education articles, case studies, expert Q&As, technical guides and other helpful tools. Click through to view each individual resource or download the master resource folder for all files in one handy location. For your convenience, this book will be updated annually as mass timber product development and the market are quickly evolving.
The U.S. Mass Timber Construction Manual was developed to give contractors and installers a framework for the planning, procurement, and management of mass timber projects, and to provide a bridge from their experience with other systems. Mass timber is unique in that it draws installation techniques from other construction types, so people with concrete, precast, tilt-up, and structural steel experience can readily adapt to these materials. However, understanding how mass timber differs from other building systems is key to cost effectiveness.
The manual was produced with primary funding from the U.S. Endowment for Forestry and Rural Communities, in collaboration with WoodWorks’ mass timber manufacturing partners in the U.S. and Canada. While intended primarily for GCs and installers, it is a useful reference for all members of a mass timber project team and anyone interested in the construction of mass timber buildings.
The scope of this guide focuses on the design of mass timber floor systems to limit human-induced vibration. The primary performance goal is to help designers achieve a low probability of adverse comment regarding floor vibrations in a manner consistent with the vibration design guides for steel and concrete systems. This includes excitation primarily from human walking as observed by other people in the building. Some treatment of design for sensitive equipment in response to human walking is also discussed. This design guide covers the range of currently available mass timber panels, including cross-laminated timber (CLT) manufactured from either solid sawn or structural composite lumber (SCL) laminations, nail-laminated timber (NLT), dowel laminated timber (DLT) and glue-laminated timber (GLT), as well as their support framework of timber beams.
The target user of this guide is a design professional with working knowledge of mass timber structural design and some background knowledge of structural dynamics as related to floor vibrations. It may be particularly useful to design engineers with limited experience with vibration analysis, experienced multi-material engineers familiar with vibration analysis but unfamiliar with mass timber vibration, and applications engineers assisting manufacturers in the development of solutions and proposals for projects.
Summarizes information on wood as an engineering material. Presents properties of wood and wood-based products of particular concern to the architect and engineer. Includes discussion of designing with wood and wood-based products along with some pertinent uses.
(1). Wood as a renewable and sustainable resource
(2). Characteristics and availability of commercially important woods
(3). Structure and function of wood
(4). Moisture relations and physical properties of wood
(5). Mechanical properties of wood
(6). Commercial lumber, round timbers, and ties
(7). Stress grades and design properties for lumber, round timber, and ties
(8). Fastenings
(9). Structural analysis equations
(10). Wood adhesives: bond formation and performance
(11). Wood-based composite materials: panel products, glued laminated timber, structural composite lumber, and wood–nonwood composites
(12). Mechanical properties of wood-based composite materials
(13). Drying and control of moisture content and dimensional changes
(14). Biodeterioration of wood
(15). Wood preservatives
(16). Finishing wood
(17). Use of wood in buildings and bridges
(18). Fire safety of wood construction
(19). Specialty treatments
(20). Heat sterilization of wood
This index is a compilation of connections used in mass timber construction. Mass timber elements are solid wood pieces with inherent fire resistance due to their mass, as defined in the 2021 International Building Code (IBC). Examples of mass timber include but are not limited to cross laminated timber (CLT), dowel-laminated timber (DLT), nail-laminated timber (NLT), glue-laminated timber (GLT), mass plywood panels (MPP), and structural composite lumber (SCL) products such as laminated veneer lumber (LVL) and laminated strand lumber (LSL). Mass timber can be used as structural floors, roofs, walls, columns and/or beams. The examples in this index illustrate a broad spectrum of connections for use in mass timber construction. Depending on the unique constraints of each project, the connection choice made by the designer may be influenced by aesthetics, load carrying capacity, fire-rating requirements, quality assurance requirements, cost and/or constructability. The purpose of the index is to facilitate the designer’s selection of project appropriate connections.
Cross-Laminated Timber (CLT) is an engineered mass timber product manufactured by laminating dimension lumber in layers with alternating orientation using structural adhesives. It is intended for use under dry service conditions and is commonly used to build floors, roofs, and walls. Because prolonged wetting of wood may cause staining, mould, excessive dimensional change (sometimes enough to fail connectors), and even result in decay and loss of strength, construction moisture is an important consideration when building with CLT. This document aims to provide technical information to help architects, engineers, and builders assess the potential for wetting of CLT during building construction and identify appropriate actions to mitigate the risk.
This comprehensive guide explains the design standards, code provisions, and safety requirements engineers need to know to use cross-laminated timber as a structural building material. The book covers all applicable design considerations, including the relevant structural load requirements and fire safety requirements.
Written by a collection of experts in the field, Cross-Laminated Timber Design: Structural Properties, Standards, and Safety introduces the material properties of CLT and goes on to cover the recommended lateral and vertical design standards. Design examples and case studies are featured throughout. You will get design recommendations for connections, building envelopes, acoustics for CLT projects, and much more. Sustainability and environmental issues are discussed in full detail.
- Covers the latest methods and design techniques being used for CLT
- Explains the code provisions in the NDS, ASCE 7, and IBC that apply to CLT
- Include contributions from some of the leading experts in the field
As part of its research work on wood buildings, FPInnovations has recently launched a Design Guide for Timber-Concrete Composite Floors in Canada. This technique, far from being new, could prove to be a cost-competitive solution for floors with longer-span since the mechanical properties of the two materials act in complementarity. Timber-concrete systems consist of two distinct layers, a timber layer and a concrete layer (on top), joined together by shear connectors. The properties of both materials are then better exploited since tension forces from bending are mainly resisted by the timber, while compression forces from bending are resisted by the concrete. This guide, which contains numerous illustrations and formulas to help users better plan their projects, addresses many aspects of the design of timber-concrete composite floors, for example shear connection systems, ultimate limit state design, vibration and fire resistance of floors, and much more.
Le bois lamellé-croisé (CLT) est un produit massif de bois d’ingénierie qui est fabriqué à partir de multiples pièces de bois de dimension assemblées en couches orthogonales avec des adhésifs structuraux. Ce produit est conçu pour des conditions de service sèches et est couramment utilisé pour construire des planchers, des toits et des murs. Comme l’humidification prolongée du bois peut causer des taches, de la moisissure, des variations dimensionnelles excessives (parfois suffisantes pour provoquer la défaillance des attaches), et même la pourriture et la perte de résistance, l’humidité est un facteur important dans la
construction avec le CLT. Le présent document a pour but de fournir de l’information technique pouvant aider les architectes, les ingénieurs et les constructeurs à évaluer les risques d’humidification du CLT pendant la construction de bâtiments et à prendre les mesures appropriées pour atténuer ces risques.
The vulnerability of any building, regardless of the material used, in a fire situation is higher during the construction phase when compared to the susceptibility of the building after it has been completed and occupied. This is because the risks and hazards found on a construction site differ both in nature and potential impact from those in a completed building; and these risks are occurring at a time when the fire prevention elements that are designed to be part of the completed building are not yet in place. For these reasons, construction site fire safety includes some unique challenges. Developing an understanding of these hazards and their potential risks is the first step towards fire prevention and mitigation during the course of construction (CoC).
Tall wood buildings have been at the foreground of innovative building practice in urban contexts for a number of years. From London to Stockholm, from Vancouver to Melbourne timber buildings of up to 20 storeys have been built, are under construction or being considered. This dynamic trend was enabled by developments in the material itself, prefabrication and more flexibility in fire regulations. The low CO2 footprint of wood - often regionally sourced - is another strong argument in its favour. This publication explains the typical construction types such as panel systems, frame and hybrid systems. An international selection of 13 case studies is documented in detail with many specially prepared construction drawings, demonstrating the range of the technology.
Comprehensive guide to engineered wood construction systems for both residential and commercial/industrial buildings. Includes information on plywood and oriented strand board (wood structural panels), glulam, I-joists, structural composite lumber, typical specifications and design recommendations for floor, wall and roof systems, diaphragms, shear walls, fire-rated systems and methods of finishing.
The CLT Handbook provides vital “How to” information on CLT for the design and construction community, and is a great source of information for regulatory authorities, fire services and others. The CLT Handbook is also a good textbook for university level timber engineering courses. In summary, the Canadian CLT Handbook will remain the most comprehensive reference for sharing the latest technical information on North American CLT.
The Canadian edition of the CLT Handbook, first published in 2011 under the Transformative Technologies Program of the Natural Resources Canada, played an imperative role in accelerating the use and acceptance of CLT in North America. Its introduction subsequently led to the publication of the US Edition. The Canadian Edition supported the early use of CLT products from Canadian manufacturers in many small to large projects across Canada and the US, and paved the way for CLT and other wood products to be used in new applications like tall and large buildings, and bridges.
Since then, additional research has taken place globally and substantial regulatory changes have occurred enabling more wood to be used in construction. Those developments highlighted a need for the CLT Handbook to be updated. The 2019 Edition of the CLT Handbook, for example, augments the recently developed CLT provisions in CSA Standard in Engineering Design in Wood and it includes a design example of an 8-storey CLT building. It helps expand the knowledge base of the designers about CLT enabling them to develop alternative solutions for taller and larger buildings that are beyond the boundaries of the acceptable solutions in building codes.
