Table of Contents
Table of Figures ——————————————————————————————– 3
Table of Tables ——————————————————————————————— 4
Abstract —————————————————————————————————— 5
- Introduction ——————————————————————————————— 6
- Literature Review ————————————————————————————– 7
2.1 Benefits ——————————————————————————————— 7
2.1.1 Energy Efficiency ——————————————————————7
2.1.2 Structural Integrity —————————————————————– 8
2.1.3 Sustainability ———————————————————————– 9
2.2 Components of Advanced Framing ————————————————————- 9
2.2.1 Floor Framing ———————————————————————- 9
2.2.2 Wall Framing ———————————————————————- 10
2.2.3 Corners ——————————————————————————11
2.2.4 Headers —————————————————————————– 12
2.2.5 Metal Hardware ——————————————————————–13
2.2.6 Single Top Plate ——————————————————————- 14
3.0 Methodology ——————————————————————————————- 15
3.1 Research Strategy ———————————————————————— 15
3.2 Structure of Selected Research Methods ———————————————-16
3.3 Selection Rationale of Participants —————————————————- 17
3.4 Restrictive Barriers ———————————————————————–19
3.5 Expectations ——————————————————————————-19
4.0 Results —————————————————————————————————20
4.1 Interviews ————————————————————————————–20
4.1.1 Interview No. 1 ———————————————————– 21
4.1.2 Interview No. 2 ————————————————————21
4.1.3 Interview No. 3 ————————————————————21
4.1.4 Interview No. 4 ————————————————————22
4.1.5 Interview No. 5 ————————————————————22
5.0 Analysis ————————————————————————————————- 23
5.1 Interviews ————————————————————————————– 23
6.0 Conclusion and Recommendations —————————————————————— 24
References ————————————————————————————————— 25
Appendix A: Interview with Vithal Outar————————————————————— 26
Appendix B: Interview with Richard Volpe————————————————————- 27
Appendix C: Interview with Luc Ross —————————————————————— 28
Appendix D: Interview with Kyle England ————————————————————- 30
Appendix E: Interview with Lucas Discenza———————————————————— 31
Table of Figures
Figure 1 – Wall Systems That Meet R20 Wall Requirements ————————————— 7
Figure 2 – Wall Frame Comparison ——————————————————————— 11
Figure 3 – Three Stud Corners ————————————————————————— 12
Figure 4 – Two Stud Corners —————————————————————————– 12
Figure 5 – Engineered Wood and Lumber Headers ————————————————— 13
Figure 6 – Opening in Non Load Bearing Walls ——————————————————- 13
Figure 7 – Single Top Plate ——————————————————————————- 14
Table of Tables
Table 1 – Advanced Framing Methods ————————————————————— 18
Table 2 – Survey Questions —————————————————————————- 18
This study aims to establish the benefits of advanced framing techniques that can be applied to platform framing to improve the quality of the structure but at the same time save energy and cut down construction costs by saving the amount of wood used. Advanced framing suggests a variation of framing techniques that are designed to reduce the amount of wood used and waste generated in construction of a wood framed house. These methods include: use of single top plates, single headers, insulated three stud corners or two stud corner with ladder blocking, 2×6 wood studs, continuous wall sheathing, use of steel clip to support headers, and reduction of metal. The purpose of this research is to examine the benefits of these techniques and to also investigate why some of these techniques are not commonly used in the industry.
Primary research consisted of interviews with the Site Super Intendant from Buttcon, Project Manager from Buttcon, Coordinator from Buttcon, architect from William Dewson Architects, and another architect from Sustainable.To Architects.
Findings, based on the interviews conclude that Buttcon contractors believe that it is worth implementing 2×6 stud walls to decrease future energy costs, but they don’t believe that some other advanced framing techniques such as using one header or one top plate should be implemented as it may require changes in the way they perform tasks. When it comes to the design aspect, the architects how ever agree that advanced framing method is a better way to build in order to save money, use less labour, and to save energy.
As mentioned previously, advanced framing is a system of framing techniques based on optimizing building materials to produce wood framed buildings with lower material and labour costs than conventional framed buildings. The Canadian Wood Frame House Construction guide and Canada Mortgage and Housing Corporation CMHC (2010) promotes advanced framing techniques, also known as optimum value engineering, to be an approach or system to reduce the amount of wood used in constructing wood framed buildings by eliminating wood where it is not necessary, reducing the amount of site generated construction waste, and to improve the R-value of the building envelope but also to reduce the construction costs. CMHC (2010) continues to explain that advanced framing positions trusses, rafter/roof joints, and flooring members directly or stacked above the load bearing studs in order for a single top plate to be used. Cripples and jack studs may also be eliminated where doors and windows locations are properly matched with between the studs. Cripples and jack studs may also be removed for non load bearing walls as they serve no structural purpose, and so those spaces can be filled with insulation. More of the advanced framing methods and techniques will be reviewed and examined in this report.
Interviews were conducted with Buttcon contractors as well as architectural firms such as William Dewson and Sustainable.To in order to gather more information on the subject. The findings were interesting since the architects had more information to offer than the contractors which is understandable, since design is their profession, but contractors did not seem to pay too much care into the building efficiency, but more towards construction savings.
2.0 Literature Review
This section of the report will review what is known regarding the benefits of advanced framing method as well as it’s components and how they can be utilized.
Components of Advanced Framing:
- Single Top Plates
- Single Headers
- Insulated Three Stud Corners or Two Stud Corner with Ladder Blocking
- In-Line Framing
- 2×6 Wood Studs Spaced @24 Inches O.C.
- Continuously Sheathed Walls – Plywood or Oriented Strand Board (OSB)
2.1.1 Energy Efficiency
APAwood (2014) argues that advanced framing meets the energy code requirements while effectively reducing the costs. Advanced framing achieves this statement by maximizing the cavity space of insulation and by minimizing the potential cavity space that may be left without any insulation. This is a result of substantial energy performance and costs savings for the developer, as well as long term energy costs savings for the owner.
By using 2×6 wood framing spaced at 24 inches on centre, wider and deeper insulation cavities can be achieved. Increasing the amount of insulations used inside the wall will improve the entire resistance to heat flow, or the R-value. Advanced framing also simplifies the installation of insulation as well as the air sealing process. Conventional framing can leave behind empty non insulated spaces in the framing at wall intersections and corners since those areas can be more difficult to insulated and seal properly. This simpler process is only achieved when advanced framing method is used, due to the fact that fewer framing members are used, and so it is easier for the builder to employ insulation coverage and succeed a tighter building envelope.
2.1.2 Structural Integrity
When advanced framing method is used with continuous wood structural panel sheathing, builders achieve a cost effective framing system that create more energy efficient homes without placing he strength or durability of the structure at risk. Plywood and OSB offer the best balance of energy efficiency, structural performance and affordability. Wood sheathed walls offer simple insulation process with all types insulation for high R-values. Plywood and OSB also offer shear strength to resist the forces of nature.
The “simplified wall bracing method using wood structural panel continuous sheathing” system report by APA (2015) offers an increased sheathing thickness called “performance category” (APA, 2015) with a tighter nailing schedule on the first story of a two story structure. APA (2015) explains that this approach will increase the performance of the bracing panels on the first storey due to the additional restriction that is provided by the structure above, through strength achieved from increased fastening and with the use of thicker wood continuous sheathing panel. This enhancement leads to reduced bracing length required in these areas which will allow for the method to be used on homes with many window and door openings.
Wood is a renewable resource that is produced in efficient methods that require less energy than other materials such as steel and concrete. When advanced framing techniques are used however, greater environment benefits are involved since material usage is optimized and construction waste is reduced. APAwood (2014) believes that using the advanced framing techniques properly may be eligible for points under National Green Building Standards and LEED.
2.0.2 Components of Advanced Framing
APAwood (2014) has a complete list of all of the main advanced framing techniques that can be applied in order to achieve maximum energy efficiency and cost savings. These improved components include:
- Floor Framing
- Wall Framing
- Metal Hardware
- Single top plates
2.2.1 Floor Framing
To achieve the best efficiency when framing the floors. Engineered wood floor joists such as I-joinss or structural composite lumber (SCL) and or glulam at 24” on centre can be used. Instead of using dimension lumber, I-joists/SCL/glulam materials will provide greater spans between foundation elements. The increase of this span will also increase the construction efficiency while reducing the costs due to using less floor joists since 24” O.C. spacing will require less number of joist, based on APA (2014), that would be around 30% lower compared to conventional 16” O.C. floor joist spacing. Another benefit of using SCL, glulam, or I-joist is the space that is available for installation of plumbing, electrical, and mechanical servies within the floor cavity, in which dropped ceilings are no longer required.
2.2.2 Wall Framing
Wall framing is the main focus of the advanced framing methods, since the wall frame provides the most opportunities for using less wood. Conventional framing usually consists of 2×4 or 2×6 wood frame spaced at 16” O.C, double top plates, three stud corners, multiple jack studs, double top plates, and unnecessary use of cripple studs.
Advanced framing offers 2×6 wood framing spaced at 24” O.C. with some or all of the other mentioned techniques, such as the use of single top plate, two stud corners, less use of jack and cripple studs, and reduction of unnecessary blocking and bridging. Appropriate sized load bearing headers are used in openings in load bearing walls as well as non load bearing walls.
The figure below illustrates the areas where advanced framing can be utilized (brown), and replace the conventional framing (yellow), and the areas that can be kept (dashed brown/yellow).
The International Residential Code IRC (2012) states that “A third stud and/or partition intersection backing studs shall be permitted to be omitted through the use of wood backup cleats, drywall clips or other approved devices that will serve as adequate backing for the facing materials”. APAwood (2014) explains that advanced framing corners can include three stud corners a.k.a. California corners, or two stud corners with ladder blocking, drywall clips. These advanced corners remove the empty cavity space that is found in conventional framing, which can be easily insulated and increase the energy savings.
Figure 3 Figure 4
Advanced framing headers are more energy efficient, as they offer cavity space for insulation inside the header. Single ply headers provide the greatest amount of cavity for insulation space. Some may question if this is a good solution or even possible; APAwood (2014) explains that these advanced framing headers are sized for the specific loads they carry, and their sizing is covered in the 2012 IRC. In addition, headers in non loading bearing walls are not even required. Cripples studs are installed between the opening top plate and the wall top plate, but can be eliminated if the distance between the header and the top plate is less than 24 inches. APAwood (2014) continues that prefabricated insulated headers and corners can be an easier option for many who want to implement this system, and they are becoming more frequently available.
2.2.5 Metal Hardware
Straps and anchors are required to resist wind loads as well as seismic forces, but these metals case thermal bridging, and so heat transfers through these metals at a higher rate than through other materials in the building. The reduction or elimination of straps and anchors will reduce the thermal bridging. APAwood (2014) states that studs above the top plate should be strapped/anchored to the ones directly below. The connection with wood panel sheathing instead of metal connectors will reduce thermal bridging and lower costs.
2.2.6 Single Top Plate
The use of single top plate can only be achieved if all members of the top floor are perfectly aligned or stacked with the members below. However, there is a maximum alignment offset allowance of 1inch. This requirement majorly applies to roof trusses, rafters, and above floor joists when single top plates are to be used.
The main objective of this primary research investigation was to conduct interviews with most experienced and qualified construction professionals, in order to gather the most valuable information possible regarding the research topic. Even though the experts interviewed were each from different fields and areas of the construction industry, their input to the interview questions provided great information based on their expertise, experience, and level of understanding on the advanced framing method.
3.1 Research Strategy
The topic will provide better understanding regarding the benefits of advanced framing when it is compared to the traditional framing methods. The research focuses on wood and energy savings as the reason to chose advanced framing is to reduce the number of wood used and increase the energy rating of the house to reduce energy costs in the long run.
Interviews with several industry professionals such as engineers, architects, framers, and construction managers can provide practical information, in which it can also be achieved by conducting surveys. Lastly, surveys can be a faster and easier method of reaching variety of audiences in the industry. Despite the possibilities, the method of email and in person interviews was applied; interviews with individual experts from various related fields provided similar and different viewpoints and information on the subject.
3.2 Structure of Selected Research Methods
Several professionals in different areas of the industry such as site superintendent, coordinator, construction manager, and architects were interviewed to obtain information based on different expertise and areas of work to help argue the benefits of advanced framing to platform framing. It must be said that it was interesting to find that even though advanced framing methods seems to work best when all of its methods are applied as one, and could provide great energy savings, some of the interviewees found a few of the advanced framing methods to be unnecessary such as applying a single top plate and removing a header and cripples. Even though the coordinator, site superintendent, and the construction manager all provided great information based on their experience in carpentry and framing, the architects that were interviewed were able to provide more in depth information since they have more knowledge and experience on the design factors of a building.
A list of different advanced framing techniques in comparison with the traditional framing (See Table 1) was provided before the questions for review by the interviewees in order for the interviewees to easily identify and understand what each question is based on and referring to. The interviews consisted of ten questions in which the interviewees were all provided with the same questions (See Table 2). The questions focused on specific advanced framing systems and their benefits to better understand how the systems can be applied to platform framing and if those benefits are worth the change when it comes to cost and mainly energy savings. With these set of questions, it is expected to receive answers that are straight to the point but also at the same time very useful.
3.3 Selection Rationale of Participants
After collecting a list of companies (25+) who have expertise in the design and construction area, interview questions were sent to these companies with a detailed message introducing the project and the purpose of the interview questions. The choice of companies was not limited to large companies, but also smaller companies who also have similar amount of experience and knowledge. Even though request for participate in the interview was sent out by email, several other interview formats such as telephone and skype were offered.
Even though engineers and architects are more suitable to provide information on the interview questions, other industry professionals such as project managers, coordinators, and site superintendents could also provide good help and information based on personal knowledge, or previous work experiences such as framing and or architectural/engineering backgrounds. For the purpose of collecting as much data as possible, there was no exclusions to other industry professionals.
The first three interviews were conducted with professionals working at Buttcon (coordinator, site superintendent, and construction manager). The purpose of conducting these interviews with these professionals was to obtain information based on their previous works as framers and to obtain their input on the construction side point of view. The other two interviews were done with architecture and design professionals who have extensive experience in residential construction.
Table 1 – Advanced Framing Methods
|Advanced Framing||VS||Conventional Framing|
|Single top plates||VS||Double top plates|
|Single headers||VS||Double headers and cripple studs|
|Insulated three stud corner or two stud corner with ladder blocking||VS||Three stud corners with isolated cavity|
|2×6 wood studs||VS||2×4 wood studs|
|Continuous wood structural panel wall sheathing||VS||Sheathing boards|
|Use steel clip to support headers||VS||Jack studs|
|Reduction of metal||VS||Use of metal hardware such as metal straps and anchors|
Table 2 – Interview Questions
|Question 1||If 2×6 stud walls offer more cavity space for insulation, why is 2×4 walls still more common?|
|Question 2||2×4 walls can hold R-13/R-15 batts while the 2×6 walls can achieve R-20 requirements for Energy Star requirements. Is the higher initial cost of 2×6 walls worth the long term energy cost savings?|
|Question 3||Can single top plates support and transfer the same load as double top plates?|
|Question 4||What must be done to achieve using only a single top plate?|
|Question 5||Instead of a double header, how can you achieve having only a single header with insulation and no cripple studs without affecting the studs bending due to the overhead load?|
|Question 6||Is it more cost effective to have double headers and cripples or single header with insulation?|
|Question 7||Which material do you prefer to use for wall sheathing and why?|
|Question 8||Since the thermal conductivity of metal is much greater than that of wood, how can metal straps and anchors be reduced or eliminated from the thermal envelope to reduce heat loss?|
|Question 9||Which of the mentioned advanced framing techniques do you believe will provide the most labour time savings? And which the least?|
|Question 10||Which of the mentioned advanced framing techniques do you believe will provide the most cost savings? And which the least?|
3.4 Restrictive Barriers
Due to advanced framing offering additional improvements to the platform framing and requiring changes in the framing methods, a person in an engineering field would best be fit to answer these questions. Given the busy schedule of individuals these days and the short time to conduct research, it was difficult to obtain high number of participants, especially without any motivation such as compensation for their time or prizes. Contacting the individuals for email interviews resulted mainly to getting no results. Maybe the reason for that could be the fact that many of these individuals did not have their personal emails available but only their ‘info’ general email address. Even though email interviews may be an easier way of conducting an interview with someone, but due to the busy schedules of construction professionals, they may have either forgotten, or did not find the reason to spend their personal time answering questions to someone they have never met before. Another barrier found was how some professionals could be rude; the first response for an interview that was received was from an architect who rudely responded saying why would anyone spend the time and answer the questions.
When analyzing the advanced framing method to platform framing, it is expected that the advanced framing method to be offering better framing techniques that can save labour time, decrease cost, and save energy. But it is also expected for some contractors to not agree with some of the advanced framing methods and to find them unnecessary. For example, they may find the use of 2×6 studs instead of 2×4 to be unnecessary when the cost of material and loss of space is considered. For those owners who building green and saving long run energy costs are important, advanced framing methods can help achieve those expectations. It is expected for advanced framing methods to increase in popularity among builders in the future as energy saving requirements are increasing rapidly. It is also expected for developers to say that some of the methods are not as good as the traditional way, and that the method is not too practical to enforce. In general, there are a lot of factors that come into play and clearly there are some reasons as to why some developers don’t use all of the advanced framing techniques in their practice.
The results of interviews were gathered and finalized shortly after. As predicted, obtaining a high number of participants was a challenge. For the primary research section of this research, information was gathered by interviewing a design build company as well as architectural companies. Three interviews were conducted with the design build company and two other interviews were done with architectural companies, and as expected, the architectural companies were able to provide more information and provide better details than the design build company. In overall, there was a good amount of details from the interviews to gather and understand to be able to analyze the benefits of advanced framing to platform framing.
As mentioned earlier, there were five interviews that was conducted with this primary research. The first three interviews were conducted with a design build company, Buttcon, and the other two interviews were conducted with architectural firms, William Dewson Architects, and Sustainable.To Architecture + Building. Even though all participants provided great amount of information, Sustainable.To Architecture + Building provided the most amount of detail as the company focuses on green, affordable, and energy efficient solutions at every scale from renovation and single family dwelling to master planning and institutional new builds.
4.1.1 Interview No. 1 – Vithal Outar (Buttcon Site Superintendent)
Mr. Outar believes that as a contractor, or someone who is in the business of the physical construction of a building, should always meet the minimum code requirements, at the same time try to save money by lowering construction costs. It comes down to the owner whether they care about if the energy efficiency of their building or not, if they do, then the contractors will construct as specified. The use of single top plate and single header seemed to be unnecessary to Mr. Outar and he suggested that perhaps shouldn’t be used.
4.1.2 Interview No. 2 – Richard Volpe (Buttcon Senior Project Manager)
Similar to first interview with Mr. Outar, Mr. Volpe also believes in constructing with minimum code requirements as it is the least costly option. How ever regarding the long term energy savings of advanced framing techniques, he explained that it is firstly important to consider the energy source, as different energy sources have different costs (ie. Hydro, coal, gas). He strongly agreed that long term energy savings are worth the higher initial cost, and it would be wise for the owner to know exactly what they want, in order to avoid upgrade costs, and to build right the first time. Mr. Volpe also believes that using a single header is not possible and didn’t think this advanced framing method is a good alternative to using double headers.
4.1.3 Interview No. 3 – Luc Ross (Buttcon Coordinator)
Similar to Mr. Outar and Mr. Volpe, Mr. Ross also believes in the fact that contractors will build with the lowest code requirements to avoid higher than required construction costs. He explained that in order to use a single top plate, the frame of the building must be perfectly aligned with the load below, and this may be harder to achieve because of labour error, and due to HVAC, plumbing, and other factors that may get in the way of perfect alignment.
4.1.4 Interview No. 4 – Kyle England (William Dewson architect)
Mr. England explained that 2×6 must be used, and IF 2×4 is used anywhere at the moment, its probably among spec home developers or contractors who are trying to save money. Advanced framing techniques are worth the initial investment of labour and higher costs, as it will provide long term energy savings. Zip System for exterior sheathing with a coating applied to the exterior surface acts as weather and air barrier which is even an improvement to the advanced method. Using a continuous insulation outside for all structural members and sheathing plus 2” of Roxul Comfortboad 80 outside of the wall sheathing can reduce the heat loss even more in which metal anchors and straps are not required to be reduced or eliminated.
4.1.5 Interview No. 5 – Nicholas Discenza (Sustainable.To architect)
Similar to interview 4 with Mr. England, Mr. Discenza agreed and supported the advanced framing methods and explained that they should be implemented as much as possible, and those who are trying to keep the conventional methods are the contractors who want to save money. 2×6 walls actually have lower initial material costs as they may be generally spaced less frequently than 2×4 studs at 16” O.C. Best way to insulate is to apply a continuous layer of insulation on the exterior of the structure. Single top plate can only be applied if the components of above floors are vertically aligned with the floor below, with very limited offset allowance. Single headers are a good solution, but if the openings are wide, then they may not be the best option. ‘METHOD.TO’ wall assembly uses ½” OSB, taped at the seams with Siga Sicrall 60 Tape which allows the sheathing to function as the vapour retarder in the assembly.
Even though it was difficult to obtain interviews, overall there was a good number of interviews to conclude and analyze research. By analyzing the results, similarities with ‘expectations’ were found. From the developer/builder/contractor point of view, some advanced framing methods could be useful, but usually it would be unnecessary to change from the methods currently used to the new advanced methods. From the architectural point of view, advanced framing can provide material cost savings, labour time savings, and has high energy cost savings in the future. The architectural point of view looks at the benefits of advanced framing and how it can benefit long term cost savings where as the contractors point of view tries to save money building.
The interview process was divided into two types of construction areas. The first type were the industry professionals working with Buttcon, the contractors on the jobsite and their input on advanced framing based on their knowledge and previous hands on experiences. The second type were the interviews with the architectures working for William Dewson Architects and Sustainable.To Architecture + Building who have a better understanding of advanced framing methods since they are always looking for new ways to build better.
Based on the interviews with Buttcon contractors it is worth implementing 2×6 stud walls to decrease future energy costs, but they don’t believe that some other advanced framing techniques such as using one header or one top plate should be implemented as it may require changes in the way they perform tasks.
When it comes to the design aspect, the architects how ever agree that advanced framing method is a better way to build in order to save money, use less labour, and to save energy. The last interview, with Nicholas Discenza from Sustainable.To Architect can be said to be the top interviewee that provided many important information. Even though other interviewees provided great amount of information, Nicholas from Sustainable.To really did provide details on how each framing system can be implemented and how their company uses innovative systems to build better. The interview with Nicholas also confirmed information that was obtained from secondary research on the benefits of advanced framing to be true. The most important finding from analyzing the interviews can be said to be the more one knows about advanced framing, the more they understand the full benefits that it can bring to platform framing.
In overall, advanced framing seems to be the better alternative to build better but also seems to have complications. Many industry professionals try to build based on code minimum requirements and are not fully aware of advanced framing methods. It may not make economical sense for example to switch from 2×4 to 2×6 studs, or reduce/eliminate the use of metal. The building methods of advanced framing still seems to be unclear for most developers, so its something new that must be learned.
6.0 Conclusion and Recommendations
The architects had a better understanding of the benefits of advanced framing than the contractors. The contractors seem to only focus on the cost of construction, and not the long term savings, perhaps this is understandable since the architects focus more on the design and contractors more on the physical construction. Even though all interviewees were able to provide valuable information on the research topic, it seemed that contractors how ever did not have as much knowledge on the advanced framing techniques, and this could be due to the fact that many contracting companies are focused on making money by continue building the way they have always known and the way that is easier for them, and not on alternative/better solutions. It is being recommended that more companies should initiate educating their employees as well as their clients on the advanced framing methods, since it can increase their reputation among competitors and clients when they have the knowledge and power to build better.
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Increase R-Values with Insulated Headers. (n.d.). Retrieved from https://www.apawood.org/designerscircle-energy-efficient-walls
Appendix A: Interview with Vithal Outar
The first interview was conducted with Vithal Outar, Buttcon Site Superintendent. The interview took place in the site office at St Michael’s Cathedral on Monday November 28th, 2016 at 4pm. The first question simply asked why is 2×4 studs still more common if advanced framing is focusing on 2×6 size studs, and Outar replied that the cost of 2×4 is less and also meets the structural requirements for what is it used for.
The second question asked if the initial cost of 2×6 wall worth the long term energy costs savings, and Outar agreed that it is definitely worth the future costs savings if it is important to the owner.
The third and forth questions ask regarding single top plates, if they can support and transfer the same load as double top plates and if so, how. Outar explained that in many cases it is not possible to have only one top plate, but if it is to be the case, different type of engineering must be conducted so the load can be evenly distributed without any damaging.
The fifth question asked for instead of a double header, how can a single header with insulation and no cripple studs be achieved without affecting the studs bending due to the overhead load. Outar believes that this method is unnecessary and shouldn’t be applied.
The sixth question asked if it is more cost effective to have double headers and cripples or single headers with insulation and Outar believes that single headers with insulation is more cost effective than double headers with cripples.
When asked about the preferred material used for wall sheathing, Outar responded that he likes using plywood over OSB as it is more structurally sound.
The eighth question asked regarding straps and anchors, since the thermal conductivity of metal is much greater than that of wood, how can metal straps and anchors be reduced or eliminated from the thermal envelope to reduce heat loss. Outar believes that the use of metal and anchors can be reduced but not eliminated. He explained that in order for the use of metal to be reduced, engineered wood must be used.
The last two questions asked regarding the mentioned advanced framing methods, which of the methods he believes are to bring the most labour and cost savings, and which the least. Outar replied that the use of 2×6 studs will have less labour and cost if 24” O.C is taken into account and 2×4 studs will require more labour and cost if 16” O.C is taken into account.
Appendix B: Interview with Richard Volpe
The second interview was conducted with Richard Volpe, Buttcon Senior Project Manager. The interview took place in the site office at St Michael’s Cathedral on Monday November 28th, 2016 after interviewing the Site Superintendent Vithal Outar. The first question simply asked why is 2×4 studs still more common if advanced framing is focusing on 2×6 size studs, and Richard replied that due to lower cost of 2×4 stud, and since 2×4 is the code’s minimum standards, it is more common. He continued that contractors usually like to use minimum code standards to decrease their costs.
The second question asked if the initial cost of 2×6 wall worth the long term energy costs savings, and Richard explained that it depends on what is the cost of the energy source such as gas, coal, hydro). He explained that since hydro is usually the main energy source, it is definitely worth building to the highest standards possible. He continued that building good the first time will save money in the long run. He also explained that if upgrade costs are considered, its cheaper to build right the first time.
The third and forth questions ask regarding single top plates, if they can support and transfer the same load as double top plates and if so, how. Richard explained that it can be done but it depends on the choice of rafter system, and direct load must be taken very serious as it is a very important factor.
The fifth question asked for instead of a double header, how can a single header with insulation and no cripple studs be achieved without affecting the studs bending due to the overhead load. Richard also believes that this system is not possible and is unnecessary if so, since headers have to have hanger to connect to studs.
The sixth question asked if it is more cost effective to have double headers and cripples or single headers with insulation and similar to Outar’s answer, Richard believes that single headers with insulation is more cost effective than double headers with cripples.
When asked about the preferred material used for wall sheathing, Richard said that it depends on the exterior envelope, but his preferred exterior sheathing is plywood as it is stronger.
The eighth question asked regarding straps and anchors, since the thermal conductivity of metal is much greater than that of wood, how can metal straps and anchors be reduced or eliminated from the thermal envelope to reduce heat loss. Richard said that maybe they can be reduced, but definitely not eliminated and that applying this system is not a wise choice due to the fact that metal straps and anchors are needed.
The last two questions asked regarding the mentioned advanced framing methods, which of the methods he believes are to bring the most labour and cost savings, and which the least. Just like Outar’s response, Richard replied that the use of 2×6 studs will have less labour and cost if 24” O.C is taken into account and 2×4 studs will require more labour and cost if 16” O.C is taken into account.
Appendix C: Interview with Luc Ross
The third interview was conducted with Luc Ross, Buttcon Coordinator. The interview took place in the site office at St Michael’s Cathedral on Monday November 28th, 2016 after the interview with Richard Volpe, Senio Project Manager. The first question simply asked why is 2×4 studs still more common if advanced framing is focusing on 2×6 size studs, and Luc replied that it is simply because it is more cost effective. Mr. Ross explained that single headers can only be used in non load bearing walls with the use of clips. The second question asked if the initial cost of 2×6 wall worth the long term energy costs savings, and Luc said yes, it is worth the long term energy costs. The third and forth questions ask regarding single top plates, if they can support and transfer the same load as double top plates and if so, how. Luc explained that the frame of the building must line studs equally and be a perfect stacked framed building. He mentioned that even though buildings are built stacked, they may not be perfectly in line due to HVAC, plumbing and other factors.
The fifth question asked for instead of a double header, how can a single header with insulation and no cripple studs be achieved without affecting the studs bending due to the overhead load. Luc explained that the only way this method can be achieved is if the location of openings are in non loading wall locations, and the use of clips can help if this advanced system is used.
The sixth question asked if it is more cost effective to have double headers and cripples or single headers with insulation and Luc believes that it depends on the type of insulation used, as insulation materials can get very expensive. But if average cost insulation is used, single header with insulation would be a more cost effective option than the double header with cripple studs.
When asked about the preferred material used for wall sheathing, Luc would rather use plywood than OSB due the strength of plywood.
The eighth question asked regarding straps and anchors, since the thermal conductivity of metal is much greater than that of wood, how can metal straps and anchors be reduced or eliminated from the thermal envelope to reduce heat loss. Luc explained that metal strapping can be replaced with wood strapping, but metal anchors can be reduced based on the situation.
The last two questions asked regarding the mentioned advanced framing methods, which of the methods he believes are to bring the most labour and cost savings, and which the least. Luc explained that using smaller size sheathing is more cost effective and the use of metal compare to wood is less cost effective.
Appendix D: Interview with Kyle England
The fourth interview was conducted with Kyle England, William Dewson Architects. The interview was done through email. Received Kyle’s response on November 29th at 2:40pm. The first question simply asked why is 2×4 studs still more common if advanced framing is focusing on 2×6 size studs, and Kyle replied that all of their project uses 2×6 for exterior walls and 2×4 for interior walls. She added that if 2×4 is more common, its likely only more common amongst spec home builders or developers trying to save money.
The second question asked was to see if the initial cost of 2×6 wall worth the long term energy costs savings, and Kyle explained that their company strive for the best possible envelope performance for the budget of the project. He added that 2×6 walls are easily worth the investment, as not only do they provide more depth for insulation but more stability/durability.
Kyle’s suggested to check out the website resources like RHD Building Science and Building Science Consulting for questions three to six.
When asked about the preferred material used for wall sheathing, Kyle said that they never use OSB, for years they have been using plywood for exterior sheathing and just recently they are exploring wall sheathing called ‘Zip System’ sheathing which has a coating applied to the exterior surface to act as a weather barrier and air barrier plane. The eighth question asked regarding straps and anchors, since the thermal conductivity of metal is much greater than that of wood, how can metal straps and anchors be reduced or eliminated from the thermal envelope to reduce heat loss. Kyle believes that by using a continuous insulation outside of all structural members and sheathing, and using 2” of Roxul Comfortboard 80 outside of the wall sheathing can reduce the heat loss even more, and metal anchors and straps wouldn’t need to be necessarily eliminated or reduced too much.
The last two questions asked regarding the mentioned advanced framing methods, which of the methods he believes are to bring the most labour and cost savings, and which the least. Kyle responded that single top plates offer best labour and cost savings where ladder blocking corner would increase the cost and labour.
Appendix E: Interview with Nicholas Discenza
The fifth interview was conducted with Nicholas Discenza, Sustainable.To Architect. The interview was conducted through email. Nickolas’ response to interview questions was received on November 29 at 10:15pm. The first question simply asked why is 2×4 studs still more common if advanced framing is focusing on 2×6 size studs, and replied that not all builders have adopted advanced framing techniques. He continued that for those who haven’t, they may believe the switch will result in additional costs as the framers’ productivity drops during the move through the learning curve. He explained that in some cases, they simply prefer to execute some details as they always have, and some details citing new techniques. While advanced framing doe offer more space for cavity insulation and less thermal bridging through the studs, not all builders are concerned with the efficiency of their walls, and not all clients have the budget for higher than code envelope performance.
The second question asked if the initial cost of 2×6 wall worth the long term energy costs savings. Nicholas explained that regarding lumber, 2×6 walls actually have lower initial material costs as they may generally be spaced less frequently than 2×4 studs. He explained that the most effective way to insulate is to apply a continuous layer of insulation on the exterior of the structure. He believes that the long term energy savings are well worth the initial investment of insulation and other techniques. He provided an example: “Consider two buildings: building A has code-minimum insulation, and building B has higher-than-code insulation. While the initial cost for B is higher, the investment will be returned in reduced energy bills. As time goes by, more and more energy (money) will be saved, to a point where the initial investment for more insulation has paid for itself in comparison”.
The third and forth questions ask regarding single top plates, if they can support and transfer the same load as double top plates and if so, how. Nicholas explained that traditionally, double top plates joined wall panels together (with single top plates of inconsistent lengths) and spread loads from joists and rafters above which were not aligned with the studs below. He said that when joists/rafters and wall studs above are perfectly in line with the studs below a single top plate can be used as it does not need to compensate for misaligned load paths; inconsistent lengths of the top plates are also ignored. He added that in order for single top plates to perform effectively, the studs, joists, rafters, and any other load bearing paths must be perfectly aligned in order to carry loads straight down, rather than requiring a double top plate to transfer the load.
The fifth question asked for instead of a double header, how can a single header with insulation and no cripple studs be achieved without affecting the studs bending due to the overhead load. Nicholas explained that the bending of a single header will greatly depend upon the loading from above and the span of the header. He added that in many cases it should be minimal; however, wider openings for sliding doors etc. may not be able to use single headers. However, this is only applicable in load bearing walls. He concluded that if the wall is non loadbearing, then bending in all cases in minimal.
The sixth question asked if it is more cost effective to have double headers and cripples or single headers with insulation and Nicholas believes that from a material standpoint, double header and cripples will cost more to construct and from an energy savings standpoint, the reduced thermal bridging of a single header with insulation should result in energy savings in the long term.
When asked about the preferred material used for wall sheathing, Nicholas responded that in their ‘METHOD.TO’ wall assembly, they use ½” OSB, taped at the seams with Siga Sicrall 60 Tape which allows the sheathing to function as the vapour retarder in the assembly. He added that without the need for a vapour barrier on the inside of the suds, the 2×4 stud cavity is left empty for running services with ease.
The eighth question asked regarding straps and anchors, since the thermal conductivity of metal is much greater than that of wood, how can metal straps and anchors be reduced or eliminated from the thermal envelope to reduce heat loss. Nicholas explained that in their ‘METHOD.TO’ wall assembly, their aim is to reduce thermal bridging by as much as possible by keeping the thermal envelope continuous. He explained that in many exterior insulation assemblies, a metal z girt is used to hold the insulation in place; but in their assembly, they have chosen to use metal fasteners that screw directly into the 2×4 framing. He added that although this is still a thermal bride through the assembly, it is currently the most effective way to mount exterior insulation until similar fasteners in some less conductive materials such as fiberglass for example, becomes available.
The last two questions asked regarding the mentioned advanced framing methods, which of the methods he believes are to bring the most labour and cost savings, and which the least. Nicholas explained that building a stud wall at 24” O.C. rather than 16” O.C. has cost savings for both material and labour as fewer studs are to buy and install, and therefore quicker framing. He added that advanced framing corners with ladder struts, drywall clips, are much more time intensive than a typical three stud corner in order to support the wall sheathing, exterior cladding, and interior drywall. He also mentioned that in terms of the least cost savings, there really isn’t a particularly bad method that he can point out.