Ontario s Building Code

Transcription

1 Ministry of Municipal Affairs and Housing Ontario s Building Code ONTARIO ONLY PROPOSED CHANGE TO THE 2006 BUILDING CODE CHANGE NUMBER E-B CODE REFERENCE Div. B DESCRIPTION OF PROPOSED AMENDMENT Revise the prescriptive energy efficiency design alternatives for non-residential buildings governed by Part 9 to reflect the performance requirements that are already scheduled to take effect after December 31, EXISTING 2006 BUILDING CODE PROVISION(S) Buildings of Non-residential Occupancy Application (1) Except where exempted by Supplementary Standard SB-10, this Subsection applies to the energy efficiency of buildings or part of buildings described in Sentence (4) Thermal Resistance of the Building Envelope (1) Except as permitted in Sentences (2) and (3), the minimum thermal resistance of all walls, ceilings and floors that separate heated space from unheated space, the exterior air or the exterior soil shall conform to Table A. Table A. Minimum Thermal Resistance of Building Assemblies Based on Degree-Day Zones (1) Forming Part of Sentence (1) Building Zone 1 Less than 5000 Degree-Days Minimum RSI Value of (2) Zone or More Degree-Days Opaque wall assembly Wall assembly adjacent to unconditioned space Below grade wall (3) Roof assembly Floor assembly over unconditioned space Column Notes to Table A.: (1) Number of degree-days for individual locations are contained in Supplementary Standard SB-1. (2) The thermal resistance determined for the building assembly shall take into account the thermal bridging in the assembly, as determined by Supplementary Standard SB-10. (3) "RSI value" shown is for insulation only. Copyright Queen's Printer for Ontario 2011 Page 1 of 7

2 (2) Where the top of a foundation wall is less than mm above the adjoining ground level, those portions of the foundation wall that are above ground may be insulated to the level required for the below grade portion of the foundation wall. (3) The minimum thermal resistance of a slab-on-ground shall conform to Table B. Table B. Minimum Thermal Resistance for Slab-On-Ground Forming Part of Sentence (3) Type of Slab-On-Ground Position of Length of, mm Minimum RSI Value Required (1) Unheated Horizontal Vertical Horizontal Heated Vertical Column Notes to Table B.: (1) "RSI value" shown is for insulation only. (4) The maximum overall coefficient of heat transfer for windows that separate heated space from unheated space shall conform to Table C. Table C. Maximum Overall Coefficient of Heat Transfer for Windows Forming Part of Sentence (4) Window-to-Wall Ratio Maximum Overall Coefficient of Heat Transfer Required, W/ m²c C less than to more than Column 1 2 (5) Except for swinging glass doors, the minimum thermal resistance of doors that separate heated space from unheated space shall be not less than RSI 0.7. Copyright Queen's Printer for Ontario 2011 Page 2 of 7

3 PROPOSED CODE CHANGE Delete Articles and and substitute the following: Application (1) Except where exempted by Supplementary Standard SB-10, this Subsection applies to the energy efficiency of buildings or part of buildings described in Sentence (4). (2) Where the ratio of the gross area of fenestration to the gross area of peripheral wall measured from grade to the top of the most upper ceiling exceeds 40%, or the ratio of the gross skylight areas to gross ceiling area exceeds 5%, the building envelope shall comply with Sentence (2) Building Envelope Requirements (1) Except as permitted in Sentence (2), the exterior building envelope shall comply with the requirements of Table (2) Except for doors, the opaque surfaces shall comply with (a) minimum RSI value of the added insulation in framing cavities and continuous insulation required in Table , or (b) maximum overall thermal transmittance U-value for the entire assembly required in Table , where U-value is provided. (3) Where the top of a foundation wall is less than mm above the adjoining ground level, those portions of the foundation wall that are above ground may be insulated to the level required for the below grade portion of the foundation wall. (4) Except for swinging glass doors, the minimum thermal resistance of doors that separate heated space from unheated space shall be not less than RSI 0.7. Copyright Queen's Printer for Ontario 2011 Page 3 of 7

4 Table Building Envelope Requirements Based on Degree-Day Zones (1) (Imperial Units) Forming Part of Sentences (1) and (2) Opaque Elements Zone 1 Less Than 5000 Degree-Days Min. R-Value Zone or More Degree-Days Min. R-Value Roofs Without Attic Space- Above Deck U R-30.0 ci U R-35.0 ci With Attic Space and Other U R-50.0 U R-60.0 Walls, Above Grade Above Grade Walls U R R-10.0 ci U R R-10.0 ci Wall, Below Grade Below Grade Wall C (2) R-10.0 ci C (2) R-10.0 ci Floors Exposed Floors U R-38.0 U R-38.0 Slab-On-Grade Floors (perimeter+below slab) Unheated Heated Fenestration R-15 for 24 in. R-15.0 for 36 in. + R-5 ci below R-15 for 24 in. + R-5 ci below R-20.0 for 36 in. + R-5 ci below Vertical Fenestration, 0%-40% of Wall Windows U U Skylight with Curb, % of Roof 0%-5.0% U U Skylight without curb, % of Roof 0%-5.0% U U Notes to Table : The following definitions apply: ci = continuous insulation (1) The overall thermal transmittance value of the entire assembly, includes air films. (2) C-Value is overall thermal conductance of the assembly but it does not include soil or air films. Copyright Queen's Printer for Ontario 2011 Page 4 of 7

5 Opaque Elements Table Building Envelope Requirements Based on Degree-Day Zones (1) (SI Units) Forming Part of Sentences (1) and (2) Zone 1 Less Than 5000 Degree-Days Min. RSI-Value Zone or More Degree-Days Min. RSI-Value Roofs Without Attic Space- Above Deck U ci U ci With Attic Space and Other U U Walls, Above Grade Above Grade Walls U ci U ci Wall, Below Grade Below Grade Wall C (2) 1.76 ci C (2) 1.76 ci Floors Exposed Floors U U Slab-On-Grade Floors (perimeter+below slab) Unheated Heated Fenestration 2.64 for 600 mm 2.64 for 900 mm ci below 2.64 for 600 mm ci below 3.52 for 900 mm ci below Vertical Fenestration, 0%-40% of Wall Windows U U Skylight with Curb, % of Roof 0%-5.0% U U Skylight without curb, % of Roof 0%-5.0% U U Notes to Table : The following definitions apply: ci = continuous insulation (1) The overall thermal transmittance value of the entire assembly, includes air films. (2) C-Value is overall thermal conductance of the assembly but it does not include soil or air films. Copyright Queen's Printer for Ontario 2011 Page 5 of 7

6 RATIONALE FOR CHANGE Problem / General Background Effective December 31, 2011, large buildings and small non-residential buildings will be required to meet an energy conservation target 25 percent higher than the 1997 MNECB. The potential changes would continue to apply this benchmark through December 31, 2016 and in doing so, acknowledge the challenges faced by industry in achieving the MNECB+25% benchmark. Part 12 of the Building Code currently contains simplified energy efficiency requirements for Part 9 non-residential buildings. Likewise, the simplified requirements in Part 12 need to be enhanced to achieve MNECB+25%. The change being considered here involves updating Part 12 so that it is consistent with the requirements. However, designers will have the option of complying with the requirements applicable to large buildings as outlined in change number E-B The compliance alternative included in this proposal is based on the 2010 edition of the ASHRAE 90.1 standard, with certain enhancements intended to achieve the MNECB+25% benchmark that is already scheduled to come into effect for large buildings after December 31, The enhancements would be set out in a revised Supplementary Standard SB-10. Alternatively, ASHRAE could also be used if the performance is improved by an additional 5 percent. This specific change would involve envelope requirements. Justification / Explanation The Green Energy and Green Economy Act, 2009 signalled a commitment to using the Building Code to support energy priorities. That legislation amended the Building Code Act, 1992 to clarify that conservation was a purpose of the Code, provided for regular reviews of the energy conservation provisions of the Code, and authorized the establishment of the Building Code Energy Advisory Council. This potential change discussed above would support Ontario s priorities related to: Reducing electricity consumption in support of Ontario s Long Term Energy Plan; Supporting the Province s climate change strategy by reducing the amount of greenhouse gases produced by the operation of buildings, and reduce greenhouse gas emissions through energy efficiency requirements; and Supporting the growth of a green economy by creating a market for energy efficient and renewable energy technologies. Cost / Benefit Implications Although the higher benchmark described above was already scheduled to come into force on December 31, 2011, higher capital costs are anticipated in meeting these requirements. Further flexibility, however, is provided for the design, which could reduce costs. Moreover, resulting operating costs could decrease. Enforcement Implications Building officials would benefit from training. Copyright Queen's Printer for Ontario 2011 Page 6 of 7

7 Who is Affected Building officials, designers, builders, manufacturers and building owners. Objective-Based Analysis Provision Objective Functional Statement Copyright Queen's Printer for Ontario 2011 Page 7 of 7