Including excerpts from the Energy Efficiency Guide (HPO) and the BC Building Code 2012

Transcription

1 Including excerpts from the Energy Efficiency Guide (HPO) and the BC Building Code 2012

2 The Energy Efficiency Provisions that have been circulating will become part of the BC Building Code effective December 19 of this year. Building permit applications made before this date do not have to comply with the new provisions. This seminar is not meant to be an in-depth evaluation of the changes, but rather a cheat sheet indicating what we expect to see in a typical single family dwelling project using prescriptive requirements identified in the Code. There is a section of the Building Code ( ) that deals specifically with energy performance compliance. The City of Nanaimo will accept performance reports from persons who have been licensed by Natural Resources Canada as and EnerGuide Rating System Energy Advisor. Nanaimo is in Climate Zone 4. The Building Code climatic data states that we are at 3000 degree days Climate Zone 5; however, calculations show that we are at 2874 degree days, lowering us from Climate Zone 5 to Climate Zone 4. The Building Code now requires Effective R values. This takes into account such things as wall plates, studs, rim joists, dryer ducts, furnace make-up and combustion air ducts, etc., when calculating the actual R value of the assembly. Having R-20 batt insulation in the wall system does not mean that it is an R-20 wall. Buildings not required to be conditioned are exempted from energy efficiency requirements. 2

3 Effective R values for single family dwellings (Zone 4 does not have any different requirements if the house has an HRV installed): In exterior walls, R20 insulation is required in 2x6 walls at 16 and 24 o.c. Minor penetrations are allowed through the walls but exclude such items like electrical panels, power meters, and pipes/conduit running parallel to the wall. This means that plumbing vents/stacks cannot be located in the outside walls unless full insulation value can be achieved (i.e. must be furred out). 3

4 Note that prior to this code change, we did not require foundation wall insulation on the stepped portion of foundation walls. 4

5 Ceilings below attics 8.67 RSI Cathedral ceilings and flat roofs 4.67 RSI Walls 2.78 RSI Foundation walls 1.99 RSI Unheated concrete floors below frost line Unheated floors above frost line 1.96 RSI Heated floors (rare) 2.32 RSI R40 R28 R20 is required in stud spaces to achieve this overall R value R10 Uninsulated but still requires foundation insulation R10 R13 Typical wall assembly Note that in order to obtain a Minimum Effective Thermal Resistance required in Nanaimo (2.78 RSI-R15.8) that R20 batts will work in the wall assembly. Various assemblies can be viewed at ww.cwc.ca. 5

6 Note that in order to obtain a Minimum Effective Thermal Resistance required in Nanaimo (2.78 RSI - R15.8) that R20 batts will work in the wall assembly. Various assemblies can be viewed at ww.cwc.ca. 6

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9 The underslab poly is required to be sealed at the top of the slab. Note that in this case, it is sealed to the interior wall poly. Crawlspace skimcoat poly will be required to be sealed to the foundation wall. 9

10 As part of the new code provisions for air tightness, underslab poly is to extend above the slab and is to either: tie into the vapour/air barrier for wood frame walls (as is the case for slab on grade construction), or be caulked to the foundation wall (as is the case for below grade basements and heated crawlspaces). 10

11 Note that once the concrete extends more than 600 mm above the ground, the exterior wall insulation requirements (R20) then apply to that portion of the concrete foundation wall. 11

12 This is an example of Structural Insulated Panel construction (SIPs) 12

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14 All electrical boxes separating conditioned space (interior to exterior and interior to attached garages) will require a gasketed box or have a flange to which sealant can be applied. This includes both wall and ceiling boxes. Gang boxes will require solid backing to ensure a proper seal (twisted studs will result in air leakage). 14

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16 This is an example of how housewrap would work in the rim joist area in order to provide an air barrier 16

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22 R20 insulation is required on these ducts. 22

23 A 2x6 wall could be used to provide adequate insulation behind the piping. Fibreglass insulation is a poor choice in this area. 23

24 Insulation with a minimum wall thickness of 1/2 is required for the first two metres in a heated space. 24

25 RSI 1.8 = R10 25

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27 Exhaust-only ventilation was previously acceptable in buildings with no naturally aspirating fuel-fired appliances (i.e., B-vented hot water tanks). Houses with electric heat typically did not require makeup air as there was no backdraft danger to occupants. 27

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29 280 m 2 (3,000 ft 2 ) Litres / sec Cu ft / min 3 bedrooms bedrooms to 200 bedrooms in a 200,000 ft 2 house

30 The fan will run continuously and the switch will be located in an area remote from the principal exhaust fan. 30

31 Room Litres / sec Cu ft / min Bathroom Kitchen A bathroom fan can be the principal exhaust fan but as it is required to run continuously, it can only have its switch in a remote area. 31

32 For homes with a furnace, this will probably be the most used system. 32

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34 The fresh air mixing fan only has to be the same capacity as the principal exhaust fan 34

35 Can be used in secondary suites and in ranchers up to 1800 square feet in area. 35

36 Passive systems cannot be used in dwelling units of more than one storey in building height and cannot exceed more than 168 square metres in area. Note that this would be a practical option for secondary suites. Note that the minimum area is 100mm x 100mm equalling 10,000 square millimetres, and not 10mm x10mm equalling 100 square millimetres. 36

37 A fresh air inlet is also required in a common living area 37

38 Transfer grilles are now required to be installed between the crawlspace and living area if the crawlspace is heated. The transfer grilles are required to be a minimum of 4 in 2 in free area for each 30 m 2 (323 ft 2 ) of crawlspace area (minimum of 2 grilles) Note: Crawlspace ventilation in this section must not be confused with exterior ventilation of unheated crawlspace. 38

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42 RSI to R value = multiplier R value to RSI =.176 multiplier Attic ceilings R40 Vaulted ceilings R28 Exterior walls R20 Floors over unheated space R28 Foundation walls R10 Heated floors (slabs) R13 Unheated floors (slabs) above frost line R10 Garage doors (when heated) R6.25 Attic hatch R15 42

43 In unfinished basements, we require the vapour barrier to be protected to 4 above the floor (not required when using styrofoam). Poly pans for exhaust fans are to be installed at the time of the fan installation. Slicing the poly pan to install it later is not acceptable. The flanges of the poly pans will require backing all around for a proper air seal. The hole for the ducting is to be tight cut to the pan and sealed with vapour barrier tape. Poly is to be returned to the window openings and sealed to the windows. Contractors are to ensure that the vapour barrier is not damaged during drywall installation. Windows, doors, and skylights now have a U value in addition to meeting the performance requirements of the North American Fenestration Standard (1.8, 1.8, & 2.9 respectively in Climate Zone 4). New energy requirements for various appliances has been adopted into the recent Energy Efficiency changes. This will affect furnaces, hot water tanks, heat pumps, air conditioners, boilers etc. Details are noted on the back of the City of Nanaimo Ventilation Checklist.

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