Structural Engineered Timber Consultation Paper

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1 Structural Engineered Timber Consultation Paper

2 Instructions We are seeking your written feedback on the proposed updates to Green Star Design & As Built and Green Star - Interiors. Your feedback is important to us and will assist us to ensure the rating tools continue to promote best practice outcomes. All feedback must be submitted by January 27th How to give feedback This is one of eight consultation papers. 1. Overview 2. Greenhouse Gas Emissions 3. Building Air Tightness 4. Life Cycle Assessment 5. Structural Engineered Timber 6. Construction Environmental Management 7. Metering & Monitoring 8. Innovation The Overview paper is a summary of critical issues that you should be aware of. The others provide detail on specific issues. You can respond to the Overview consultation paper, any of the detailed consultation papers, or all. You can give as much or as little feedback as you wish. You do not need to complete all the questions if you do not wish to. There are two ways to send feedback to us. 1. Respond to questions within the consultation papers then press submit. An will be sent to GBCA. 2. Send a written submission. You can send us a written submission instead or in addition to written comments in the consultation papers. Please send your feedback to designandasbuilt@gbca.org.au. If you are unsure where to put your comment, don t worry, all comments will be considered. Just save your comments and press submit and it will be sent to GBCA or send it to us via . Further information If you have questions on how to provide feedback, we will be hosting a free webinar on December 6th at 12:30pm. Click here to sign up. If you missed the date, it will be available for viewing from December 7 th free of charge. For further information or assistance with the submission papers or consultation process, please contact Naomi Martin (naomi.martin@gbca.org.au) or Karl Desai (karl.desai@gbca.org.au). Respondent Details 1. Name 2. Company Are you submitting on behalf of your company? Y N 1

3 Contents Instructions... 1 Contents... 2 Request for Feedback... 3 Background... 3 Overview... 4 Technical Requirements... 5 Pathway Criteria B.4.0 Minimum Product Attributes B.4.1 Reduced Embodied Impacts B.4.2 Industry Capacity Building... 6 Documentation Requirements... 7 Appendix A: Draft Credit

4 Request for Feedback The Green Building Council of Australia (GBCA) is proposing to introduce a prescriptive pathway for rewarding the use of structural engineered timber within the Life Cycle Impacts credit in Green Star Design & As Built v1.2. This rating tool will be released in the second quarter of This Consultation Paper seeks industry input on the proposed introduction, the language within the credit and whether any additional guidance or aspects need to be clarified. The Consultation Paper has been developed by the GBCA s Structural Engineered Timber working group. To assist in the consultation for this topic, a draft version of the Life Cycle Impacts Engineered Timber credit has been prepared and attached as Appendix A. It is recommended that this consultation paper be read in conjunction with this draft. Interested parties are requested to provide feedback on this Consultation Paper no later than Friday 28 January Background Buildings with an engineered timber structure offer valuable life cycle impact reductions. This includes less embodied energy impacts when compared to traditional structural materials, increased use of pre-fabrication resulting in construction efficiencies and the use of a renewable source material. Recently, engineering advancements have enabled timber to be used more readily in structural applications throughout Australia. Europe is recognised as leading the global field for its use and production of structural engineered timber. The increasing local relevance has been supported with building code provisions for tall-timber construction. This has been ably assisted with flagship projects receiving broad industry support. 3

5 Overview Buildings constructed from a primarily engineered timber structure are currently only rewarded in Green Star by undertaking a life cycle assessment (under the Performance Pathway). The life cycle assessment rewards projects for the environmental impact reductions, however does not directly reward other flow-on benefits. To support the uptake of building s being constructed from engineered timber, an Engineered Timber Prescriptive Pathway is being proposed, similar to Steel, Concrete and Building Reuse. The below illustration indicates in red where the pathway will be introduced. Life Cycle Impacts Credit Performance Pathway (7 points available) Prescriptive Pathway (5 points available) 19A Life Cycle Assessment 19B.1 Concrete 19B.2 Steel 19B.3 Building Re-use 19B.4 Engineered Timber The GBCA s Structural Engineered Timber working group represents industry specialists on the topic with previous project experience. The group have identified the main considerations for the use of structural engineered timber in Green Star and developed a draft credit in response. The development process involved multiple meetings to determine such items as the best measures required, practicality of implementation, level of supporting documentation required etc. This credit is attached as Appendix A. Questions provided in the Technical Requirements section of the paper link to the proposed requirements in the draft credit. Do you agree with the introduction of a Prescriptive Pathway for recognising the use of structural engineered timber? Please explain why you agree with the introduction, or not. 4

6 Technical Requirements Pathway Criteria 1. Do you agree with the proposed criteria in the draft credit? Are there any other considerations the GBCA should have in rewarding the use of structural engineered timber? 19B.4.0 Minimum Product Attributes 2. Do you agree with the Minimum Product Attributes requirements? If not, please explain why. 19B.4.1 Reduced Embodied Impacts 3. Is the method for calculating the structural engineered timber used in the building by area clear? Is there any additional guidance required? 4. Do you agree with the 30% and 70% benchmarks? If not, please explain why. 5

7 19B.4.2 Industry Capacity Building 5. Do you agree with the three initiatives being rewarded under Industry Capacity Building? Will it result in any negative outcomes? Any suggestions for improvement? 6. Do you agree with the 50% (by volume) benchmark under Industry Capacity Building? If not, please explain why. Scope of Pathway 7. Do you agree with limiting the scope of this pathway to engineered timber only? OR should the criterion be expanded to include the structural use of non-engineered timber? For example, milled timber in cassette construction. Please explain the rationale for either approach. Guidance 8. Is there any additional guidance required? 6

8 Documentation Requirements 9. Is the documentation required to support compliance clear and easy to produce? Any suggestions for improvement? 10. Any final comments / suggestions? 7

9 Appendix A: Draft Credit 8

10 LIFE CYCLE IMPACTS - ENGINEERED TIMBER Credit 19B.4 Points available: 3 PATHWAY CRITERIA 19B.4.0 Minimum Product Attributes The minimum requirement is met where all structural engineered timber used in the building meets best practice requirements for: Formaldehyde emissions limits; Volatile organic compounds limits; and Responsible sourcing. 19B.4.1 Reduced Embodied Impacts Up to 2 points are available where the building is constructed from the following proportion of structural engineered timber: For 30% of the building s GFA 1 point; and For 70% of the building s GFA 2 points. 19B.4.2 Industry Capacity Building 1 point is awarded where at least 50% (by volume) of the structural engineered timber used is manufactured or fabricated in Australia or New Zealand. If the structural engineered timber used represents less than 30% of the building s GFA, then the Life Cycle Impacts Engineered Timber pathway (19B.4) cannot be targeted. Please see question 1 to provide feedback. COMPLIANCE REQUIREMENTS 19B.4.0 MINIMUM PRODUCT ATTRIBUTES It is a minimum requirement for this criterion that all structural engineered timber used in the building meets the requirements of the following criteria in this rating tool: 13.1 Indoor Pollutants Paints, Adhesives, Sealants and Carpets the requirements for adhesives and sealants only apply; 13.2 Indoor Pollutants Engineered Wood Products ; and 20.2 Responsible Building Materials Timber Products. Compliance shall be demonstrated by either achieving the above criteria or providing all relevant supporting documentation in this criterion submission. Please refer to the Documentation Requirements section. Please see question 2 to provide feedback. 9

11 19B.4.1 REDUCED EMBODIED IMPACTS Up to two (2) points are awarded based on the proportion (by gross floor area) of structural engineered timber used in the building. Any gross floor area (GFA) that is constructed and / or supported from structural engineered timber is deemed compliant. Any GFA where the vertical structure is not primarily structural engineered timber shall not be included as compliant area. This may include concrete cores, lift shafts or hybrid material structure. Floor area calculations shall be taken from above the ground plane, inclusive of any on-grade or ground floor slab. Any floors located below ground should not be included in the area calculations. Additionally, calculations only apply to the new floor area constructed as part of the project s scope of works existing floor area should be excluded. Please see question 3 to provide feedback. Where the minimum requirement is met, the following points will be awarded: For 30% of the building s GFA 1 point; and For 70% of the building s GFA 2 points. Points will be awarded on a sliding scale basis, up to one decimal place. For example, where the structural engineered timber used in the building is 40% of the GFA, 1.3 points will be awarded. Please see question 4 to provide feedback. 19B.4.2 INDUSTRY CAPACITY BUILDING One (1) point is awarded where at least 50% (by volume) of the structural engineered timber used has engaged the local market in the manufacturing or fabrication process. Initiatives rewarded include any of the following: Source timber grown in Australia or New Zealand; Structural engineered timber products manufactured in Australia or New Zealand; or Structural engineered timber products imported from overseas and fabricated in Australia or New Zealand. This may include cutting, finishing, routing of imported products; or the manufacture of sub-assemblies or building components. This criterion aims to develop the relatively new structural engineered timber market locally. Benefits include the widespread adoption of this relatively low environmental impact material and the creation of local jobs and a skilled workforce. Please see questions 5 and 6 to provide feedback. 10

12 DEFINITIONS Structural engineered timber Made primarily of wood based components remanufactured into a structural member and complying with the requirements of AS : Timber Structures. These products include Cross Laminated Timber (CLT), Laminated Veneer Lumber (LVL), Glulam and timber I-beams. The following applications of engineered wood products are excluded from the scope of this credit: Non-structural applications such as particleboard, plywood, Medium Density Fibreboard (MDF) and decorative overlaid wood panels; Non-engineered wood products such as milled timber; and Formwork. Please see question 7 to provide feedback. Additional Information Additional information can be found in the following documents: AS : Timber Structures GUIDANCE INTERACTION WITH OTHER GREEN STAR CREDITS Buildings with a primary engineered timber structure reduce the use of traditional structural materials, namely concrete and steel. This results in a physically lighter building with overall reductions in embodied environmental impacts. Accordingly, this pathway may be combined with 19B.1 Life Cycle Impacts Concrete, 19B.2 Life Cycle Impacts Steel or 19B.3 Life Cycle Impacts Building Reuse to obtain points. Where a reference case is required, a building using a concrete or steel structure may be used to demonstrate improvements. Please refer to the specific criterion s Guidance section for defining the reference case. Please also ensure that the cost of the concrete (19B.1) or steel (19B.2) represents at least 1% of the project s contract value in order to target the relevant criterion. Please see question 8 to provide feedback. 11

13 DOCUMENTATION REQUIREMENTS Please refer to the How Documentation is Described in the Submission Guidelines section within the Introduction for further guidance on Documentation Requirements for project submissions. DESIGN REVIEW SUBMISSION (OPTIONAL) Projects teams must submit documentation marked with an asterisk* for Design Review. Additional supporting documentation should also be provided to demonstrate commitment to, or confirmation of, credit compliance. AS BUILT SUBMISSION All project teams shall submit the following documentation: Submission Template* Supporting Documentation Project teams must submit documentation supporting credit compliance. The following is a list of recommended documents that may be used to demonstrate compliance. Alternate documentation to that listed below can be used by project teams to demonstrate compliance if the documents listed below are not available. The key requirement is that evidence is provided to support each claim made within the Submission Template. List of recommended documents: 19B.4.0 Minimum Product Attributes Where the minimum requirement for the structural engineered timber has not been met by achieving the corresponding criteria, provide Documentation Requirements as per the following: o o o 13.1 Indoor Pollutants Paints, Adhesives, Sealants and Carpets the requirements for adhesives and sealants only apply; 13.2 Indoor Pollutants Engineered Wood Products ; and 20.2 Responsible Building Materials Timber Products. Where the minimum requirement for the structural engineered timber has been met by achieving the corresponding criteria, no further documentation is required in this criterion submission. 19B.4.1 Structural Reduced Embodied Impacts Floor plans and section drawings marked-up identifying which areas of the building are constructed and / or supported from structural engineered timber. Area schedule identifying the compliant proportion of the building s GFA. Structural Engineer s report including summary calculations of the compliant proportion of the building s GFA. 19B.4.2 Industry Capacity Building Chain of custody certificates demonstrating the source of the timber used has been grown or manufactured in Australia or New Zealand. Invoices or purchase receipts demonstrating that the structural engineered timber used has been manufactured or fabricated in Australia or New Zealand. The monetary values of the products may be blacked out given calculations are to be based on volume. 12

14 Bill of quantities demonstrating that at least 50% (by volume) of the structural engineered timber used meets any of the three available initiatives. Cross-references should be made to the chain of custody certificates, invoices or purchase receipts being provided. Please see question 9 to provide feedback. 13