Future Residential Construction
An Exploration of Cross-Laminated Timber
Stephan Inabnit
Rising energy costs, inflation, and the ever-growing pressures of climate change have quickly forced people to reassess the construction methodology of residential construction. In addition, architectural reactions to the housing crisis vary widely, thus leaving many questions concerning economic and political stances towards residential construction methodology. This mixed reaction has caused a variety of responses, some of which have already been put into place, while others will not be implemented for the next decade. Many home builders have been forced to explore new building materials during the Covid 19 pandemic to overcome supply chain issues. These explorations range from simplified i-joist to higher-rated R-value materials to help create more efficient homes. This sparked discussions about why the housing industry has taken so long to adopt better construction methods. However, as economic inflation rises in a post-Covid world, these materials no longer help maintain somewhat affordable housing.
Causing other builders, engineers, and architects to exploit newer construction methodologies. Many are already heavily used in other parts of the world yet have remained an anomaly in the United States housing market. In addition, they would require years of developing the necessary infrastructure to implement on a large scale. These newer methodologies range from various mass timber options to 3D printed homes and even modular homes. This thesis will focus on the exploration of a mass timber product called cross-laminated timber (CLT) construction and the possibility of it replacing stud frame construction in the next ten to twenty years. Using CLT as the primary building material to develop multiple prototype homes comparable in size to standard stud frame homes. Once developed, these CLT homes will be evaluated and compared to their stud frame counterparts to determine if this method could replace stud frame construction. Specific comparisons include total cost, construction time, carbon footprint, material management, and building envelope.
CLT Panel Production Design Process Detail Wall Section & Joinery
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CONTENTS
Prototypes
CLT Panel Production
4.2 Panel Design
In order to create an efficient design and construction process the development of the CLT panel is vital for this project. The panels would need to require the least amount of cnc cutting required while also maintaining a simplistic construction process to ensure no skilled labor is required. These panels are 10 foot by 60ft as the initial size, then are cut down at in whole number dimensions to ensure simple dimensions as well as create the least amount of waist possible. This method can be repeated over and over thus standardizing the panel process and creating the first layer of modularity. The second layer of standardization and modularity takes place in the assembly of the wall system itself. The exterior walls are cladded with moisture barriers as well as wood fiber insulation, a cladding system, and the exterior cladding material. This process is done to in order from inner most layer (CLT) to outer most layer (exterior cladding) allowing for a simple yet efficient assembly line process. These simple details may not seem very important, however, in the grand scheme of the overall design and construction of a CLT building this detailed process can shave large amounts of time in the design phase as well as the panel assembly phase as there will be an established set of procedures in place. Considering a larger amount of the buildings budget goes into the design phase for this type of building method, by lowering the complexity of the design and standardizing how the CLT panels will all be cut and assembled it can lower the overall cost of the building making it more cost effective.
1. STANDARD CLT
2. CNC OPENINGS
3. APPLY WEATHER PROOF MEMBRANE
4. MOUNT WOOD FIBER INSULATION
5. APPLY WEATHER PROOF MEMBRANE
6. ADD CLADDING SYSTEM
7. APPLY EXTERIOR CLADDING
8. INSERT DOORS & WINDOWS
Design Process
4.2 Design Process
The design process for the prototypes starts with defining standardized materials that will be used in each prototype. These materials range from the CLT panels, the type of joints used, Window types and dimensions, insulation, door dimensions, roof pitch, and exterior claddings. This standardization was inspired by the precedents and their unique characteristics and applying them into an array of materials that allow for a creative design process while maintaining a high level of construction and cost efficiency. This is to ensure that these prototype CLT homes aren’t just comparable with their stud frame counterparts but exceed their predecessors while still remaining competitive in price even with the limited infrastructure. The next step is establishing the building footprint by setting a square footage goal for the prototype.
STANDARD CLT PANEL
MULTIPLE PANELS EXTRUDE
PROGRAMMATIC SHIFTING
APPLY CLT WALL PANELS
EXTRUDE OPENINGS
EXTERIOR CLADDING
APPLY ROOF SYSTEM
Detail Wall Section & Joinery
Screws CLT Floor
Plywood, SCL, LVL
Panel to Panel
Self-Tapping Screws Wall to Wall
CLT Wall CLT Wall
CLT Wall CLT Wall CLT Floor
Self-Tapping Screws Wall to Floor
Self-Tapping Screws
Roof to Wall
CLT Wall
CLT Roof
CLT Wall
SCL
Metal Plate
Lag Screws
Anchor Bolt
Cement Footing
Wall to Foundation
Prototype 1
First Floor
1 A 1 A 2 A 2 A 1600 Sqft
Structural Diagram
Section 1-A
Section 2-A
Environmental Impact
70
TOTAL TREES
TOTAL ACRE = 24.91 TREES = 0.36 ACRE
= =
3 PLY = 3.5” THICK
60’ 10’
2.43 TREES
WHITE PINE DOUGLAS FIR / ACRE
CLT Panel Layout
Prototype 2
1 B 1 B 2 B 2 B
Floor
Diagram
1600 Sqft
First
Structural
Second Floor
Section 1-B
Section 2-B
TOTAL TREES
TOTAL ACRE = 23.3 TREES = 0.29 ACRE 70 WHITE PINE DOUGLAS FIR / ACRE
= = 3 PLY = 3.5” THICK 60’ 10’ 2.43 TREES
= = 5 PLY = 5.67” THICK 60’ 10’ 4.05
TREES
Environmental Impact
CLT Panel Layout
Prototype 3
First Floor
1 C 2 C 1 C 2 C 2400 Sqft
Structural Diagram
2-C
Section 1-C Section
Environmental Impact
TOTAL TREES
TOTAL ACRE = 24.3 TREES = 0.30 ACRE
70 WHITE PINE DOUGLAS FIR / ACRE
= =
10’
3 PLY = 3.5” THICK 60’
2.43 TREES
CLT Panel Layout
Prototype 4
Floor
Diagram
Floor 1 D 2 D 1 D 2 D 2400 Sqft
First
Structural
Second
Section 1-D
Section 2-D
TOTAL ACRE = 43.3 TREES = 0.54 ACRE 70 WHITE PINE DOUGLAS FIR / ACRE
= = 3 PLY = 3.5” THICK 60’ 10’ 2.43 TREES
TOTAL TREES
= = 5 PLY = 5.67” THICK 60’ 10’ 4.05
TREES
CLT Panel Layout Environmental Impact
Prototype 5
First Floor Structural Diagram First Floor First Floor 1 2 1 2 E E E E 3600 Sqft
Section 1-E Section 2-E
TOTAL TREES
TOTAL ACRE = 45.8 TREES = 0.57 ACRE
70 WHITE PINE DOUGLAS FIR / ACRE
= = 3 PLY = 3.5” THICK 60’ 10’ 2.43 TREES = = 5 PLY = 5.67” THICK 60’ 10’ 4.05 TREES
CLT Panel Layout Environmental Impact
Prototype 6
3600 Sqft 1 2 1 2 F F F F
First Floor
Structural Diagram
Section 1-F
Section 2-F
Environmental Impact
TOTAL TREES
TOTAL ACRE = 65.6 TREES = 0.82 ACRE
70 WHITE PINE DOUGLAS FIR / ACRE
= =
=
10’
3 PLY
3.5” THICK 60’
2.43 TREES
CLT Panel Layout
Prototype 7
3600 Sqft First Floor Structural Diagram Second Floor 1 2 1 2 G G G G
2-G
Section 1-G Section
TOTAL TREES
TOTAL ACRE = 70.47 TREES = 1.10 ACRE
70 WHITE PINE DOUGLAS FIR / ACRE
= = 3 PLY = 3.5” THICK 60’ 10’ 2.43 TREES = = 5 PLY = 5.67” THICK 60’ 10’ 4.05 TREES
Impact
CLT Panel Layout Environmental
