CSA Z Technical Requirements for Manufactured Homes Implications of the More Significant Proposed Changes

Transcription

1 CSA Z Technical Requirements for Manufactured Homes Implications of the More Significant Proposed Changes Prepared for the CSA Technical Committee 21 March 2014

2 Contents 0. Introduction 1 1. Roof Deflections Z and NBC Requirements Implications of Referencing the NBC 2 2. Lintels Z and NBC Requirements Implications of Referencing the NBC 3 3. Resistance to Lateral Loads Z240 MH and NBC Requirements Implications of Referencing the NBC 4 4. Energy Efficiency 10 4A. Building Envelope Climate Zones 10 4B. Building Envelope - Insulation 10 4B.1 Z240 MH and NBC Requirements 10 4B.2 Implications 12 4C. Building Envelope Windows and Doors 13 4C.1 Z240 MH and NBC Requirements 13 4C.2 Implications 14 4D. Building Envelope Tradeoffs 15 4D.1 NBC Requirements 15 4D.2 Implications 15 4E. Building Envelope Airtightness 15 4E.1 Z240 MH and NBC Requirements 15 4E.2 Implications 16 4F. HVAC Ducting and Piping 16 4F.1 Z240 MH and NBC Requirements 16 4F.2 Implications 17 4G. HVAC Controls and Equipment 17 4G.1 Z240 MH and NBC Requirements 17 4G.2 Implications 18 4H. Service Water Heating Piping and Equipment 18 4H.1 Z240 MH and NBC Requirements 18 4G.2 Implications 19 4J. Performance Path 20 References 20 i Implications of the More Significant Proposed Changes Page i

3 0. Introduction Proposed General Reference to the NBC Many of the current requirements in Z240 MH Series are copies of requirements in the National Building Code (NBC) or they reference NBC requirements. It is proposed that the next edition of the standard reference the NBC as a general requirement and provide explicit requirements and exceptions only where these are needed to address issues that are specific to manufactured homes. Implications General Where Z240 MH does not copy or reference NBC requirements, the resultant technical changes may range from minimal to quite significant sometimes making the requirement less stringent and sometimes more stringent. This document provides information on the proposed changes that could result in notably more stringent requirements. Table 1 summarizes the impact of the proposed NBC reference depending on jurisdiction, climate and seismic load. Table 1 Summary of Impact of General Reference to the NBC Province, Territory Z240 MH Recognized Implications Snow loads (1) Lateral Loads (1) Energy (lintels) Wind Seismic Efficiency BC Yes Yes Yes Yes Yes AB (4) SK unofficially (2) Yes Yes (5) MB Yes, unofficially (3) Yes Yes ON Yes Yes Yes QC depends on Yes -- Yes Yes municipality NB unofficially (2) Yes Yes NS Yes Yes (6) PE depends on -- Yes municipality NL depends on Yes Yes -- Yes municipality YK Yes Yes -- Yes Yes NT depends on Yes Yes -- Yes municipality NU depends on municipality Yes Yes Notes on Table: (1) Does not affect all locations (2) Z240 MH homes are accepted even though the standard is not recognized in the applicable regulation. (3) Z240 MH homes appear to be accepted beyond the regulated limit to mobile homes. (4) Alberta has indicated its intent to adopt the NBC Part 9 energy efficiency requirements. (5) Saskatchewan has plans to adopt the NBC Part 9 energy efficiency requirements. (6) Nova Scotia s energy efficiency requirements apply to all Part 9 buildings Implications of More Significant Proposed Changes Page 1 of 20

4 1. Roof Deflections 1.1 Z and NBC Requirements Limits and Test Criteria Table 2 provides the deflection limits and test criteria for deflection limits and sustained loads for roof beams, rafters, joist and trusses as specified in the current Z and the NBC. Roof-Ceiling Assembly Table 2 Z and NBC Roof-Ceiling Deflection Requirements Deflection limit Test criteria Z NBC Z NBC* Beams, rafters or joists* gypsum board or plaster L/360 L/360 other than gypsum board or plaster span 4.3 m L//240 L/240 span < 4.3 m L/180 L/240 no ceiling span 4.3 m L/240 L/180 span < 4.3 m L/180 L/180 - live load - good engineering practice - dead loads need not be considered - otherwise, design per Part 4 Trusses when tested (sustained) gypsum board or plaster L/360 L/360 not gypsum board or plaster span 4.3 m L//240 L//240 span < 4.3 m L/180 L/180 Notes to Table: * Z does not mention roof joists. 2-2/3 x design roof snow load for 24 h 1-1/3 x design roof snow load after 1 h total ceiling load (dead load + live load) of 0.35 kpa + 2-2/3 x specified live roof load for 24 h ceiling load + 1-1/3 * specified roof snow load for 1 h 1.2 Implications of Referencing the NBC Beams and Rafters no change for beams or rafters where the ceiling is gypsum board Trusses where trusses are tested, ceiling load must be added for sustained loading and deflection to recognize increasing loads from insulation no change where compliance is demonstrated by calculation Note In the code development cycle, the Standing Committee on Housing and Small buildings will be reviewing the differences between the requirements for trusses compared to those for beams, rafters and joists. There is also a proposed change to delete the testing option. Implications of More Significant Proposed Changes Page 2 of 20

5 2. Lintels 2.1 Z and NBC Requirements Table 3 provides: the current Z Table 4 Wood Lintel Spans, and an excerpt from NBC Table A-15 Maximum Spans for Spruce-Pine-Fir Lintels, No. 1 or No. 2 Grade, Non-structural Sheathing showing the spans for lintels supporting roof and ceiling only with a tributary width of 4.9 m maximum. Comparable spans are highlighted. Table 3 Z and NBC Lintel Requirements Z Table 4 Excerpt from NBC Table A-15 Depth of lintel, mm 38 mm 64 mm studs* Studs exceeding 38 mm 64 mm Maximum allowable span, m Lintel size Maximum Span, m Exterior Walls Specified Snow Load, kpa Int r walls x x x x x *Lintels consist of one 38 mm thick piece of lumber and one 19 mm thick piece of lumber on edge. Lintels consist of two pieces of 38 mm thick lumber on edge, separated by filler pieces. Compared to the NBC spans, the Z spans: do not address snow loads exceeding 1.5 kpa nor 1.0 kpa for longer spans NBC span table values have changed over time to recognize changes in lumber properties. 2.2 Implications of Referencing the NBC Lintel dimensions would increase where snow loads exceed 1.5 kpa and where they exceed 1.0 kpa for longer spans. The lintel dimensions would recognize: changes in lumber properties snow loads in 286 to 416 additional locations (depending on building width) that exceed 1.5 kpa. While the NBC does not explicitly recognize 38 mm x 64 mm load bearing studs, these could still be used based on equivalence, or a change request could be submitted to have these added to the Code. Implications of More Significant Proposed Changes Page 3 of 20

6 3. Resistance to Lateral Loads While the NBC lateral load resistance requirements appear to be complicated, many sentences, clauses and table entries do not apply to single storey homes with normal weight roofing. 3.1 Z240 MH and NBC Requirements Application The application of the current Z240 MH and NBC requirements is summarized in Table Implications of Referencing the NBC Overview For most locations identified in NBC Appendix C, traditional construction practice is unaffected by the lateral load requirements. As shown in Table 3, homes installed on Resolution Island, NU and in La Malbaie, Baie Saint Paul and La Pocatiere, QC must be deigned according to Part 4. The following describes the implications for manufactured homes that may be designed and constructed under Part 9 but where additional lateral resistance is required. For many designs, it is likely that the only changes will be: the construction of braced wall panels in one interior partition additional fastening of - rim joists/beams to the sill plate - braced wall panels to framing above and below - roof framing to wall framing (a few locations for wind only) - sheathing and interior finishes that provide required lateral resistance. Where the home is constructed on a steel frame, the fastening of the floor assembly to the frame will need further review and is proposed to be addressed in the context of updates to Z regarding seismic loads. Important Terminology Term Definition Shown in Plan Figures as Braced wall band Braced wall panel an imaginary continuous straight band extending vertically and horizontally through the building or part of the building, within which braced wall panels are constructed a portion of a wood-frame wall where bracing, sheathing, cladding or interior finish is designed and installed to provide the required resistance to lateral loads due to wind or earthquake Implications of More Significant Proposed Changes Page 4 of 20

7 Table 4 Z240 MH Requirements and Application of NBC Requirements Wind), kpa 1-in-50 hourly wind pressure (HWP Seismic seismic spectral response acceleration (Sa(0.2)) Z240 MH all locations 0.70* no requirements NBC Traditional construction Additional lateral resistance required Design to Part 4 all locations not identified below Northwest Territories Holman /Ulukhaqtuuq 0.86 Alberta Cowley 1.01 Pincher Creek 0.96 Newfoundland and Labrador Cape Race 1.05 St Anthony, NF 0.87 Bonavista 0.84 all locations not identified below 0.80 HWP 1.2 kpa 0.70 < Sa(0.2) < 1.2 British Columbia Langford 1.2 Sidney 1.20 Tofino 1.20 Ucluelet 1.20 Victoria (Gonzales Hts) 1.20 Victoria (Mt Tolmie) 1.20 Victoria 1.20 Bamfield 1.10 Crofton 1.10 Duncan 1.10 Ladysmith 1.10 Sooke 1.10 Cloverdale 1.10 Ladner 1.10 Langley 1.10 White Rock 1.1 Nanaimo 1.00 Port Renfrew 1.00 Richmond 1.00 Surrey (88 Ave & 156 St.) 1.00 Youbou 1.00 Abbotsford 0.99 Jordan River 0.99 New Westminster 0.99 Haney 0.97 HWP >1.2 kpa Resolution Island, NU 1.23 Vancouver 0.95 (Granville & 41 Ave) Vancouver 0.94 (City Hall) Mission City 0.93 Burnaby 0.93 (Simon Fraser Univ.) North Vancouver 0.88 West Vancouver 0.88 Sechelt 0.87 Tahsis 0.87 Parksville 0.86 Qualicum Beach 0.82 Gold River 0.80 Chilliwack 0.76 Port Alberni 0.76 Alberni 0.75 Squamish 0.72 Quebec Riviere du Loup 1.00 St-Georges-de-Cacouna 0.80 Montmagny 0.73 Yukon Destruction Bay 0.73 Haines-Junction 0.72 Sa(0.2) 1.2 La-Malbaie, QC 2.30 Baie Saint Paul, QC 2.10 La Pocatiere, QC 2.00 Note to Table: * The proposed change to Z clause (5.2.3) would require design to 0.70 kpa or the HWP at the installation site whichever is greater. NBC to No technical implications beyond the application described above. NBC Braced Wall Bands Requirements Relevant to Manufactured Homes Braced wall bands are limited to max. 1.2 m wide Exterior walls must be located within the braced wall bands Max. spacing between centre-lines of braced wall bands are as shown in Table 5. Implications of More Significant Proposed Changes Page 5 of 20

8 Table 5. Max. Spacing of Braced Wall Bands Seismic Wind 0.70 < Sa(0.2) < Sa(0.2) < HWP 1.2 kpa Maximum distance between centre lines of braced wall bands, m (ft) 10.6 (34.78 ) 7.6 (24.94 ) 7.6 (24.94 ) Implications where there are jogs in an exterior wall the entire wall must be located within the 1.2 m wide braced wall band (Fig. 1a), OR the lines of both walls must be considered to be on braced wall bands and the requirements for braced wall panels apply to both bands (Fig. 1b) where length (or less likely, width) of a module is greater than the limits in Table 5 plus 1.2 m, intermediate cross-walls must be constructed with braced wall panels (Fig. 1c). Fig. 1a Fig. 1b Fig. 1c Figure 1 Braced Wall Bands NBC Braced Wall Panels (Spacing and Dimensions) Requirements Relevant to Manufactured Homes 1. Braced wall panels must be within braced wall bands. 2. Except as described in point 4, maximum spacing and minimum dimensions of braced wall panels must be as shown in Table The maximum distance between braced wall panels may be increased to 7.3 m provided that the length of all the braced wall panels within the braced wall band is not less than 1.2 m. [NBC Additional System Considerations] 4. Exception for Sunrooms The perimeter of a single space need not comply with points 1. to 3. above provided the roof of the space is framed max. 400 mm o.c. and: a) projects not more than m from the face of the framing in the nearest parallel braced wall band, and - half the perpendicular plan dimension, b) is either - integral with the roof of the rest of the building, or - fastened to the wall framing. Implications of More Significant Proposed Changes Page 6 of 20

9 max. 7.6 m 27-0 max. 7.6 m Table 6 Spacing and Dimensions of Braced Wall Panels Seismic Wind 0.70 < Sa(0.2) < Sa(0.2) < HWP 1.2 kpa Maximum distance between edges of braced wall panels, m (ft) 6.4 (21) 6.4 (21) 6.4 (21) Maximum distance from end of a braced wall to the edge of the closest braced wall panel, 2.4 (7.87) 2.4 (7.87) 2.4 (7.87) m (ft) Minimum length of individual braced wall panels panel located at the end of a braced wall band where the braced wall panel connects to an intersecting braced wall panel, mm (in) panel not located at the end of a braced wall band or braced wall panel located at the end of a braced wall band where the braced wall panel does not connect to an intersecting braced wall panel, mm (in) Minimum total length of all braced wall panels in a braced wall band 600 (23.62) 750 (27.76) 25% of braced wall band Implications See Figure 2 as an example. max. 7.6 m max. 7.6 m min 600 mm max. 1.2 m max. 6.4 m max. 6.4 m min 600 mm max. 2.4 m min. 750 mm max. 1.2 m Figure 2 Spacing Dimensions for Braced Wall Panels Implications of More Significant Proposed Changes Page 7 of 20

10 NBC Materials in Braced Wall Panels Requirements Relevant to Manufactured Homes In general, normal structural sheathing and interior gypsum board with minimum thicknesses shown in Table 7 must be installed and with options if wood-based interior finishes are used For modules more than 15 m (49.2 ) long, the braced wall panels in one intermediate braced wall must be constructed with OSB or plywood on both sides. Table 7 Braced Wall Panel Materials and Thicknesses Panel Type Cladding, Sheathing or Interior Finish Minimum Thickness, mm With supports 400 mm o.c. With supports 600 mm o.c. Gypsum board interior finish Sheathing complying with CAN/CSA-O325 W16 W24 OSB O-1 and O2 grades and waferboard R-1 grade Plywood Diagonal lumber Other NBC Requirements and Implications Other requirements that apply and their implications are summarized in Table 8. Table 8 Other Requirements to Address Wind Load and Implications Code Ref Subject, Application Implications Wood-Frame Construction Nailing of Framing Sentence (1) and wind and seismic Table closer centres mm o.c. vs. 2 per joist or blocking for rim joist, trimmer joist or blocking supporting braced wall panels to sill plate or top wall plate vs. 400 mm o.c. exterior walls bottom plate of braced wall panels to floor joists, rim joists or blocking vs. 600 mm o.c. to framing below interior walls to framing above and below Sentences (3)(4) wind only tying roof framing to wall framing min. 50 mm x 0.91 mm (2 x 21 gage) galvanized strips Fastening for Sheathing Sentence (2) and wind and seismic increased fastener lengths Table B wind only roof sheathing 50 mm o.c. within 1 m of roof edges Anchorage Sentence (3) -- no implications for 1-storey buildings Support of Walls (that provide required lateral resistance) Sentence (6) wind and seismic continuous support required Required Roof Sheathing no implications Sentence (1) wind and seismic continuous lumber or panel-type sheathing required Lumber roof sheathing no implications Sentence (2) wind and seismic lumber sheathing must be diagonal Table continued next page Implications of More Significant Proposed Changes Page 8 of 20

11 Table 8 (Continued) Code Ref Subject, Application Implications Gypsum Board Finish Spacing of Nails Closer centres where gypsum board provides required lateral Sentence (4) wind and seismic resistance - max. 200 mm o.c Spacing of Screws Closer centres where gypsum board provides required lateral Sentence (4) wind and seismic resistance max. 300 mm o.c Plywood Finish Nails and Staples increased fastener lengths Sentence (2) wind and seismic fastening in accordance with requirements for sheathing Sentence (2) Particleboard, OSB or Waferboard Finish * Nails increased fastener lengths Sentence (2) wind and seismic fastening in accordance with requirements for sheathing Sentence (2) Note to Table 7: * Particle board is not permitted to be used to provide required lateral resistance An alternative recognized by Part 9 is design according to the Canadian Wood Council s Engineering Guide for Wood Frame Construction. Implications of More Significant Proposed Changes Page 9 of 20

12 4. Energy Efficiency 4A. Building Envelope Climate Zones The NBC building envelope energy efficiency requirements vary depending on climate zone. See Figure 3. Zone 8 Zone 7B Zone 7A Zone 6 Zone 5 Zone 8 Zone 7B Zone 7A Zone 4 Zone 6 Zone 5 Zone 6 Zone 5 Figure 3 Climate Zones and Heating Degree Days 4B. Building Envelope - Insulation 4B.1 Z240 MH and NBC Requirements General Thermal Insulation Requirements For the six climate zones, Table 9 shows the Z240 MH insulation RSI values and (R-values) in bold black NBC RSI values and (equivalent insulation R-values) in blue, with optional reduced values for houses with an HRV in green italic. Implications of More Significant Proposed Changes Page 10 of 20

13 Table 9 NBC and Z240 MH Thermal Resistance Requirements (1) Climate Zone and Maximum Number of Heating Degree Days, C Effective RSIe Floors Walls Attics Insulation, RSI (R) (2) Effective RSIe (3) Insulation, RSI (R) (4) Effective RSIe Insulation, RSI (R) (5) Cathedral Ceilings, Flat Roofs Effective RSIe Insulation, RSI (R) (6) Zone 4 < (31) (19) (40) (31) Zone to 3999 Zone to 4999 Zone 7A 5000 to 5999 Less than 6000 Zone 7B 6000 to 6999 Zone to less than (31) (31) (35) (27) (35) (35) (27) (27) 8000 and more (35) 4.23 (24) 3.88 (22) 4.23 (24) 3.88 (22) 4.23 (24) 3.88 (22) 3.0 (17) 4.83 (24+3.4) 4.23 (24) 4.83 (24+3.4) 4.23 (24) 3.87 (22) 4.83 (24+3.4) 4.23 (24) 3.87 (22) (50) 7.1 (40) (31) (50) (31) (60) 8.8 (50) 5.7 (32) (35) 5.7 (32) (60) (35) (60) 6.7 (38) (60) 7.0 (R40) (35) 6.7 (38) (35) 7.0 (R40) Notes to Table: (1) Z240 MH values in bold black; NBC values without HRV in blue; NBC values with HRV in green where these differ from values without HRV (2) Insulation values for floors assume lumber framing at 400 mm (16 ) o.c. Using wood-i joists would permit the use of RSI 494 (R28) and RSI 547 (R31) in Zones 4-6 and 7A-8 respectively. (3) Air films, hollow-backed vinyl siding, 9.5 mm (3/8 ) OSB exterior sheathing, 12.7 mm (1/2 ) interior gypsum board contribute RSI 0.43 ( ). 25 mm Type 1 expanded polystyrene insulation contributes an additional RSI 0.65 (R 3.4) for a total of RSI 1.08 (4) Insulation values for walls assume 38 mm x 140 mm (2 x 6 ) framing at 400 mm (16 ) o.c. Insulation values illustrate examples of compliant assemblies most likely to be used for manufactured homes. (5) Insulation values for attics assume framing at 600 mm (24 ) o.c. (6) Insulation values for cathedral ceilings and flat roofs assume framing at at 400 mm (16 ) o.c. Using wood-i joists would permit the use of RSI 494 (R28) and RSI 547 (R31) in Zones 4-6 and 7A-8 respectively. Additional Thermal Insulation Requirements Structural Penetrations NBC requirements address major structural penetrations through the insulation. These will typically not apply to manufactured homes. Permitted Reductions for Services Installed within the Building Envelope The effective thermal resistance of walls must be maintained where mechanical, plumbing or electrical components (pipes, ducts, conduits, cabinets, chases, panels, recessed heaters, etc.) are placed within the wall assembly. Except for ducts, where these are placed within a floor assembly, the floor insulation may be reduced to provide not less than RSI e (R e 15.8). Where a duct is installed below the floor framing, further reductions are permitted provided additional insulation is provided on the sides of the duct. Implications of More Significant Proposed Changes Page 11 of 20

14 Rim Joists Rim joists must be insulated to the same level as the walls above. Attic Insulation at the Eaves The NBC specifies a minimum RSI 3.52 (R-20) over exterior walls compared to the Z minimum of RSI 2.1 (R12), and limits the zone of reduced insulation to 1200 mm measured from the exterior of the wall. 4B.2 Implications General Table 10 summarizes the implications of the NBC insulation requirements Climate Zone Zone 4 Zone 5 Zone 6 Zone 7A Zone 7B Zone 8 Table 10 Summary of Implications of NBC Thermal Resistance Requirements Floors Walls Attics Where installed in joist space, requires min. 10 floor joists Where installed in joist space, requires min. 12 floor joists Insulation >R-20 in 2 x 6 stud spaces or advanced framing (2) Requires exterior insulation, HRV, or insulation >R-20 in 2 x 6 stud spaces plus advanced framing (2) Significant increases. See below re. Attic Insulation at Eaves 4D. Building Envelope Trade-Offs Cathedral Ceilings, Flat Roofs (1) No implications Increase by R-3 No implications Notes to Table: (1) The NBC Standing Committee on Housing and Small Buildings will be reviewing the NBC limits for cathedral ceilings and flat roofs in the code development cycle. (2) Some work has been done to show that R-20 batts and advanced framing can provide RSI 3.5 with reduction in framing cost. Further work is needed to demonstrate the benefits of advanced framing where higher RSI values are required. Attic Insulation at the Eaves The minimum RSI 3.52 (R-20) over the exterior walls can be achieved with a 2 x 6 upper chord and a compressed R22 batt. The 1200 mm horizontal limit for reduced insulation precludes 3/12 roof slopes except in the mildest climate zone unless the trusses have raised heels. Implications of More Significant Proposed Changes Page 12 of 20

15 4C. Building Envelope Windows and Doors 4C.1 Z240 MH and NBC Requirements General Z240 MH specifies no thermal performance criteria for windows or skylights. Z240 MH specifies min. RSI 0.7 for doors. This is equivalent to maximum overall thermal transmittance (U) of This limit, however, applies only where the 2.5% January design temperature is lower than -15 C while the NBC criteria are based on heating degree days. The January design temperature is an appropriate metric for systems design but not for energy efficiency. There are locations listed in NBC Appendix C that are in climate Zones 4 to 7A where the January 2.5% design temperature is -15 C or warmer. Table 11 identifies the NBC performance criteria for windows doors and skylights. Table 11 NBC Requirements for Windows, Doors and Skylight Climate Zone Windows and Doors Skylights Max. U Min. Energy Rating Max. U Zone Zone Zone Zone 7A Zone 7B Zone Exceptions One exterior door is permitted to have a maximum U 2.6. Note re. British Columbia The British Columbia Energy Efficiency Act specifies criteria for windows, skylights, sliding glass doors and hinged doors. These apply to all buildings. The criteria that would apply to manufactured homes are provided in Table 12. Exceptions are permitted for windows, skylights and sliding glass doors provided the average performance of all units meets the minimum performance level. Table 12 BC Energy Efficiency Act Criteria Component Windows and Sliding Glass Doors frame other than wood or metal wood frame metal frame Max. U-value Skylights 3.10 Hinged Doors 2.00 Implications of More Significant Proposed Changes Page 13 of 20

16 4C.2 Implications Windows NBC The criteria for site-built windows provide some indication of the types of windows that may comply with the performance criteria. These are provided in Table 13. Climate Zone 4 and 5 6 and 7A 7B and 8 Option Table 13 NBC Criteria for Site-Built Windows nonmetallic Frame Glazing Low-e coating Spacer thermally panes panes argonfilled mm size, broken double triple none with with metallic nonmetallic 1 X X -- X X -- X -- X X 3 -- X -- X X X X X X X -- X X X X X X X British Columbia For homes installed in BC, compliance with the Energy Efficiency Act is less onerous than compliance with the NBC. (The BC Building Code requirements are the same as the NBC.) Doors NBC Except where the Z240 MH requirement does not apply, the NBC criteria are less stringent than Z240 MH in climate Zones 4 to 7A. Considering the exception in the NBC, if a home has only one hinged door, all the NBC requirements are less stringent. British Columbia The BC EE Act is less stringent than the NBC. (The BC Building Code requirements are the same as the NBC.) Implications of More Significant Proposed Changes Page 14 of 20

17 4D. Building Envelope Tradeoffs Application All homes 4D.1 NBC Requirements With some limitations such as maximum reduction in RSI, the NBC allows trade-offs as shown in Table 14. Table 14 Permitted Building Envelope Trade-Offs Reduced Performance Balanced by Increased Permitted Performance one or more opaque areas of the building envelope one or more opaque areas of the building envelope All homes one or more windows one or more windows Homes where: total window and door area (excluding skylights) 15% of the gross wall area subfloor to ceiling 2.34 m (7-8 ) subfloor to bottom truss chord or ceiling joist 2.39 m (7-10 ) one or more floor areas or ceiling areas under sloped roofs provided by difference between 17% window, skylight and door area and actual window, skylight and door area Trading Floor and Attic Insulation for Window and Door Areas The NBC trade-off permitting reduced floor and/or attic insulation where windows and door area is limited recognizes the dimensional challenges faced by manufactured homes in some regions of the country. 4D.2 Implications Reduced Attic Insulation where Window Area is Limited Calculations indicate that attic insulation can be reduced to less than R50 in all instances where there is limited window area and that the required insulation can be installed in 14 -wide homes with 4/12 roof slope. To maintain this low level of attic insulation in the two coldest climate zones, either additional exterior wall insulation or an HRV must be installed. 4E. Building Envelope Airtightness 4E.1 Z240 MH and NBC Requirements General Z currently references the NBC building envelope requirements for air barriers. The proposed general reference to the NBC would include the Section Energy Efficiency requirements as well. These provide the options of complying with: a set of prescriptive construction requirements a maximum leakage rate of 0.02 L/(s*m 2 ) when tested according to CAN/ULC S742, Air Barrier Assemblies Specification at 75 Pa Implications of More Significant Proposed Changes Page 15 of 20

18 OR a maximum leakage rate of 0.02 L/(s*m 2 ) when tested according to ASTM E 2357, Determining Air Leakage of Air Barrier Assemblies where the building will not be subjected to 1/50 sustained wind loads exceeding 0.65 kpa. (This standard could be used for all but 27 locations listed in NBC Appendix C.) Specific The NBC energy efficiency requirements for air barriers specify: air barrier material compliance with CAN/ULC S741, Air Barrier Materials Specification sealant material compliance with one of a number of standards specific constructions for various penetrations, joints and junctions. 4E.2 Implications Compliance with Test Standard factory-construction practices should be such that manufactured homes should comply with the performance limit of 0.02 L/(s*m 2 ) when tested at 75 Pa. Compliance with prescriptive Requirements The prescriptive construction requirements essentially describe accepted good practice. Standard factory-construction practices should be such that manufactured homes should comply. 4F. HVAC Ducting and Piping 4F.1 Z240 MH and NBC Requirements Duct Sealing and Insulation The application of the NBC duct sealing requirement is not as broad as in Z240 MH. The NBC, however, does not permit the use of fabric backed tape with rubber adhesives to provide the required airtightness. Z240 MH requires exposed ducts to be insulated to a minimum of RSI 1.23 (R-7). The NBC requires, in general, that ducts be insulated to the same level as walls. An exception allows a minimum RSI 2.11 (R-12) under ducts installed under an insulated floor provided additional insulation is installed on the sides so that there is no increase in the total heat loss. An Appendix table provides a number of deemedto-comply solutions for various climate zones and duct dimensions. Pipe Insulation The NBC requires that piping installed outside the building envelope, except high temperature refrigerant piping, be insulated to the same level as walls. Z240 MH has no requirement. Implications of More Significant Proposed Changes Page 16 of 20

19 Dampers The NBC requires all duct openings to be equipped with a damper except: where dampers are not permitted by other regulations on air intakes in locations with fewer than 3500 heating degree days (climate Zone 4 and some locations in climate Zone 5). 4F.2 Implications Duct Sealing and Insulation Sealing Manufactured homes should comply with the NBC requirement provided fabricbacked tape with rubber adhesive is not used. Insulation Depending on the proximity of ducting to the eaves, manufactured homes should be able to meet the insulation requirement for ducts installed in attics. For single-section homes where transportation height limits are stringent, the insulation of ducts installed under the floor framing is more of a challenge. With additional insulation on the sides of the duct, RSI 2.11 can be used in Zone 4, and in Zones 5 to 7A provided an HRV is installed. Otherwise, additional thickness must be provided or the insulation material must be more effective. The latter should become a practical option with the expected approval of an NBC proposed change to permit foam plastic insulation for ducts (some limitations apply). Dampers Except in climate Zone 4 and some locations in climate Zone 5, depending on current practice there may be an additional cost for dampers. 4G. HVAC Controls and Equipment 4G.1 Z240 MH and NBC Requirements Controls The NBC requirements specify various types of controls that must be installed and required characteristics of those controls. Equipment The NBC specifies required performance levels for HVAC equipment. Equipment efficiencies are the same or somewhat more stringent than the energy efficiency ratings specified by the national Energy Efficiency Act. Table 15 provides a few examples for heating equipment. Implications of More Significant Proposed Changes Page 17 of 20

20 Table 15 Selected Heating Equipment Efficiencies Equipment Min. Performance gas-fired warm air furnace AFUE 92% gas fired unit heater Et 82% oil-fired warm air furnace AFUE 85% 4G.2 Implications Controls Required controls are standard. Equipment Incremental costs as of December 2011 are provided in Table 16 for gas- and oil-fired forced air furnaces. There is no incremental cost for electric heating. Factory Location Table 16 Selected Incremental Heating Equipment Costs (Ref. 3) Gas/Propane Fuel Oil Vancouver $286 $1,144 Edmonton $291 $1,165 Winnipeg $280 $1,123 Toronto $260 $1,040 Montreal $260 $1,040 Halifax -- $ 998 4H. Service Water Heating Piping and Equipment 4H.1 Z240 MH and NBC Requirements Piping - Insulation The NBC requires the first 2 m of piping to and from the storage tank to be insulated with min. 12 mm thick pipe insulation piping installed outside the building envelope to be insulated to the same level as required for the walls. Implications of More Significant Proposed Changes Page 18 of 20

21 Equipment The NBC specifies required performance levels for service water heating equipment. Equipment efficiencies are the same or somewhat more stringent than the energy efficiency ratings specified by the national Energy Efficiency Act. Table 17 provides a few examples. Table 17 Selected Service Water Heating Equipment Efficiencies Equipment Storage-Type electric Min. Performance SL V (top inlet) SL V (bottom inlet) gas fired EF V oil-fired EF V Tankless gas fired EF 0.80 oil-fired EF V 4G.2 Implications Piping Incremental costs as of December 2011 for pipe insulation are provided in Table 17. Table 17 Insulation Costs Factory Location Incremental Cost Vancouver $55 Edmonton $56 Winnipeg $54 Toronto $50 Montreal $50 Halifax $48 Equipment Incremental costs as of December 2011 are provided in Table 18 for selected equipment. Implications of More Significant Proposed Changes Page 19 of 20

22 Table 18 Selected Incremental Service Water Heating Equipment Costs Factory Location Gas/Propane Energy Electricity, Oil Vancouver $483 $175 Edmonton $492 $175 Winnipeg -- $175 Toronto $439 $175 Montreal -- $175 Halifax -- $175 4J. Performance Path The NBC provides the option of demonstrating compliance through a performance compliance path. Energy consumption is calculated for the proposed house and for a reference house of the same dimensions and orientation designed according to the prescriptive requirements for the same installation location. The proposed house complies provided it uses no more energy than the reference house. This option allows for considerable flexibility in the design of the house. References 1. CAN/CSA-Z MH Series Manufactured Homes. Canadian Standards Association, Toronto, National Building Code of Canada 2010, 2012 Revisions. National Research Council of Canada. Ottawa, Cost and Benefit Analysis of Proposed Changes for the Energy Efficiency in Housing and Small Buildings in the National Building Code. Proskiw Engineering. December Proposed Changes for the Energy Efficiency in Housing and Small Buildings in the National Building Code Building Envelope Cost Estimate Analysis. Hanscomb Consultants. Ottawa, September 26, Proposed Changes for the Energy Efficiency in Housing and Small Buildings in the National Building Code HVAC and service Water Heating Systems Cost Estimate Analysis. Hanscomb Consultants. Ottawa, September 26, Implications of More Significant Proposed Changes Page 20 of 20