Obc 2012 sb 10 becor 2017 03 29
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A review of the Ontario Association of Architects Practice Tips on Energy Conservation with in depth presentation of OBC SB-10 prescriptive compliance paths and the changes to the Code which came into effect Jan 01, 2017.
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Obc 2012 sb 10 becor 2017 03 29
- 1. BECOR OAA Practice Tips & OBC Part 12, SB – 10 Prescriptive Solutions 2017 03 29 Gerry Conway OAA, FRAIC, ia AIA, LEED AP
- 2. OAA PTS & SB-10 • Architects, Interns & Architectural Technologists, • Engineers & Engineering Technologists, • Owners & Developers, • Builders & Trades, • Researchers and Teachers, • AHJs, • Manufacturer’s & Suppliers, • Lawyers, • The Public? 2017 03 29 Who? Copyright Conway Architect Inc.
- 3. OAA PTS & SB-10 • OAA Practice Tips • PT 36.2 SB-10 Prescriptive Compliance • A few Basics • SB-10 Building Envelope 2012 vs 2017 • ASHRAE 90.1 Building Envelope 2010 vs 2013 2017 03 29 Outline Copyright Conway Architect Inc.
- 4. OAA PTS & SB-10 • NECB 2015 Prescriptive Compliance • NECB Simple Trade-Off • ASHRAE 189.1-2014 • ASHRAE 90.1-13 vs. ASHRAE 189.1-14 vs. NECB-15 2017 03 29 Outline Copyright Conway Architect Inc.
- 5. OAA PTS • PT.3 Code Matrix • PT.4 Code Review • PT.5 General Review • PT.14 Record Dwgs. • PT.19 ASHRAE 90.1 • PT.23 CCDC • PT.35 Seismic • PT.36 Energy 2017 03 29 OAA Practice Tips Copyright Conway Architect Inc.
- 6. OAA Practice Tips B-10 OAA PTS Copyright Conway Architect Inc.
- 7. SB-10 • HDD18 = ∑ 18⁰C - Mean Daily Temperature below 18⁰C in a year. • SB-10 at Concept Design • Fenestration Impact on Energy Use. • Envelope Impact on M&E. • Models require Prescriptive Values. 2017 03 29 Basics Copyright Conway Architect Inc.
- 8. SB-10 • U = Thermal Transmittance W/m²•K ⁰ • C = Thermal Conductance W/m²•K ⁰ - BLs • F = Perimeter Heat Loss Factor for SoG in W/m•K ⁰ • In all energy codes the above are effective values for complete assemblies. 2017 03 29 Basics Copyright Conway Architect Inc.
- 9. SB-10 2017 03 29 U = Thermal Transmittance W/m²•K ⁰ = 1/R Copyright Conway Architect Inc.
- 10. SB-10 • Effective U, C & F values take into account Parallel Path Loses • Parallel Path Losses: heat losses through framing, structural penetrations, etc. • R = Thermal Resistance = m²•K ⁰/W 2017 03 29 Basics Copyright Conway Architect Inc.
- 11. SB-10 2017 03 29 Effective U, C & R Opaque Assemblies EE4 Copyright Conway Architect Inc.
- 12. SB-10 2017 03 29 Effective U, C & R Opaque Assemblies ASHRAE 90.1 Appendix A Copyright Conway Architect Inc.
- 13. SB-10 2017 03 29 Parallel Path Losses Image from PhotoBucket Copyright Conway Architect Inc.
- 14. SB-10 2017 03 29 Effective U Fenestration Copyright Conway Architect Inc.
- 15. SB-10 2017 03 29 Effective U Fenestration Copyright Conway Architect Inc.
- 16. SB-10 • ASHRAE Standard 90.1-2013 + Division 3, Chapter 2, • ASHRAE Standard 90.1-2010 + Division 3, Chapter 2 as it read Dec. 31, 2016 (Until Dec 31, 2017 ), • ASHRAE Standard 189.1-2014 , Section 7 • National Energy Code of Canada for Buildings 2015 + Division 3, Chapter 3. Part 3 Buildings Prescriptive, Trade-Off & Performance Solutions 2017 03 29 Copyright Conway Architect Inc.
- 17. SB-10 • ASHRAE Standard 90.1-2010, + 5% + 13% • National Energy Code of Canada for Buildings 2011 + Division 2, Chapter 3 + 13% • Model National Energy Code for Bldg. 1997 + 25% + 13% (Until January, 1st 2018) • ASHRAE Standard 90.1-2010, + Division 2, Chapter 2 + 13% Part 3 Buildings Performance Solutions 2017 03 29 Copyright Conway Architect Inc.
- 18. SB-10 • Are you exempt? • Determine the areas of Walls (above & below grade), Roofs, Exposed Floors, Windows, Doors and Skylights • Read SB-10 and ASHRAE 90.1, NECB or ASHRAE 189.1 • Is the Building Airtight? Prescriptive Procedure 2017 03 29 Copyright Conway Architect Inc.
- 19. SB-10 • Use HDD18 in SB-1 for Zone • % Structural Penetrations • Record and distribute required U, C, F and R • Select assemblies factoring in U, C, F, R and Parallel Path Loses • M&E Requirements Prescriptive Procedure 2017 03 29 Copyright Conway Architect Inc.
- 20. SB-10 USI W/m²°C (RSI m²°C/W) USI W/m²°C Req. Req. Prov. In Contact with Ground ● Roofs below Grade 0.284 (3.521) ● Walls C Value 0.284 (3.521) ● Slab on Grade F Value - Unheated Perimeter 1200mm 0.676 (2.600) - Heated Continuous Insulation CI 1.045 (0.900) Above Grade ● Roofs - Ins. Entirely above Deck 0.164 (6.098) - Metal Building 0.148 (6.757) - Attic & Other 0.107 (9.346) ● Walls - Mass 0.261 (3.831) - Metal Building 0.256 (3.906) - Steel Framed 0.250 (4.000) - Wood Framed 0.261 (3.831) Prescriptive Procedure Record & Distribute 2017 03 29 Copyright Conway Architect Inc.
- 21. SB-10 • Design Building = Reference Building • ASHRAE 90.1 Appendix C • Software required • Revit Insight 360 • CAN-Quest v 1.5 MNECB 1997 • COMcheck v 4.05 SB-10 Div. 2 • And others Simple Trade-Off Procedure 2017 03 29 Copyright Conway Architect Inc.
- 22. SB-10 ASHRAE 90.1 2013 + SB-10 2017 Div. 3, Chap. 2 Prescriptive Solution 2017 03 29 Copyright Conway Architect Inc.
- 23. Copyright Conway Architect Inc.
- 24. SB-10 ASHRAE 90.1 2013 Mandatory Provisions 2017 03 29 • 5.4.3.1 Loading Dock Weather seals • 5.4.3.4 Vestibules • 5.5.4.5 Fenestration Orientation 90.1-2013 West ≤ 25% East ≤ 25% 90.1- 2010 AS ≥ AW & AS ≥ AE Copyright Conway Architect Inc.
- 25. SB-10 ASHRAE 90.1 2010 vs 2013 2017 03 29 • 5.1.3.1 Storm windows to have low e if existing glazing doesn’t. • 5.1.3.5 & 6 Clarification of Re- roofing exemption. • Appendix C - 2010: Detailed trade off process Modelling Recommended • Appendix C - 2013: Modelling Required Copyright Conway Architect Inc.
- 26. SB-10 SB-10 2017 Div. 3, Chap. 2 Changes Prescriptive Solution 2017 03 29 Copyright Conway Architect Inc.
- 27. SB-10 2017 03 29 Copyright Conway Architect Inc.
- 28. SB-10 SB-10 2017 Changes Referenced Standards 2017 03 29 Copyright Conway Architect Inc.
- 29. SB-10 Div. 3, Chap. 2 2012 & 2017 Change from Div. 2, Chap. 2 2012 2017 03 29 NON RESIDENTIAL TABLE SB 5.5-6 SI Zone 6 2012 2017 Roofs U R U R • Insulation Above Deck 0% 0% 10% 17% • Metal Building 2% 0% 14% 30% • Attic and Other 1% 0% 12% 23% Walls, Above Grade • Mass 62% 96% 47% 22% • Metal Building 21% 13% 17% 22% • Steel Framed 26% 17% 24% 20% • Wood Framed and Other 5% 5% 0% 0% Wall, Below Grade C R C R • Below Grade Wall 83% 96% 83% 94% Copyright Conway Architect Inc.
- 30. SB-10 Div. 3, Chap. 2 2012 & 2017 Change from Div. 2, Chap. 2 2012 2017 03 29 NON RESIDENTIAL 2012 2017 Floors U R U R • Mass -1% -1% 23% 27% • Steel Joist -1% 0% 10% 10% • Wood Framed and Other 2% 0% 9% 9% Slab-On-Grade Floors F R F R • Unheated 1% 0% 13% 100% • Heated ? 0% 0% -29% 80% ± Opaque Doors U R U R • Swinging 0% 0% -11% 0% • Non-Swinging -11% 0% Copyright Conway Architect Inc.
- 31. SB-10 Div. 3, Chap. 2 2012 & 2017 Change from Div. 2, Chap. 2 2012 2017 03 29 NON RESIDENTIAL Fenestration 2012 2017 Vertical Fenestration % Wall 0% 0% U SHGC U SHGC VT / SHGC • Non-metal framing: all 0% 0% -13% 0% 1.10 • Metal framing: fixed 0% -7% • Metal framing: Ent. Door 0% 55% • Metal framing: all others 0% -35% Skylights % Roof 0% 67% • Skylight with Curb, Glass, 0% 0% 48% 15% 1.10• Skylight with Curb, Plastic 0% 0% 53% 23% • Skylight without Curb, All 0% 0% 0% 15% Copyright Conway Architect Inc.
- 32. SB-10 NECB 2015 + Div. 3, Chap. 3 Prescriptive Solutions 2017 03 29 Copyright Conway Architect Inc.
- 33. SB-10 Div. 3, Chap. 3 + NECB 2015 Vs. Div. 3, Chap. 2 + ASHRAE 90.1 2013 2017 03 29 • 4000 - 7000 HDD FDWR 40% - 20% Ottawa: 4500 HDD, FDWR: 37% • HDD18 & HDD15 • Residential = Non-Residential = Semi-heated • No limits on glazing per orientation. Copyright Conway Architect Inc.
- 34. SB-10 Div. 3, Chap. 3 + NECB 2015 Vs. Div. 3, Chap. 2 + ASHRAE 90.1 2013 2017 03 29 • A Wall is a Wall, a Roof a Roof • Below grade: Wall U = Roof U • Insulation to extend to 2.4m below grade • All fenestration types treated the same in any given Zone. Copyright Conway Architect Inc.
- 35. SB-10 Div. 3, Chap. 3 NECB 2015 Simple Trade-Off Path 2017 03 29 •∑ 𝒏 𝑼𝒊𝒑 𝑨𝒊𝒑 ≤ ∑ 𝒏 𝑼𝒊𝒓 𝑨𝒊𝒓 • Some caveats: • The FDWR and SRR of the reference building must = that of the proposed building. • You can’t trade walls with roofs Copyright Conway Architect Inc.
- 36. SB-10 Div. 3, Chap. 3 NECB 2015 Simple Trade-Off Path 2017 03 29 ∑ 𝒏 𝑼𝒊𝒑 𝑨𝒊𝒑 ≤ ∑ 𝒏 𝑼𝒊𝒓 𝑨𝒊𝒑𝒓 𝑼 𝒇𝒑 𝑨 𝒇𝒑 + 𝑼 𝒐𝒑 𝑨 𝒐𝒑 ≤ 𝑼𝒇𝒓𝑨𝒇𝒓 + 𝑼𝒐𝒓𝑨𝒐𝒓 Above Grade Reference Building Proposed Building U Area Area x U U Area Area x U W/m²°C m² Req. W/m²°C m² Prov. ● Walls 0.247 252 62 0.095 231 22 ● Fenestration 1.900 144 274 1.900 165 314 ● Doors 1.900 4 8 1.900 4 8 ∑ Area x U 343 ꓿ 343 Max Area x U 343 - 321 ꓿ 22 Max Uw 22 ÷ 231 ꓿ 0.095 Copyright Conway Architect Inc.
- 37. SB-10 Div. 3, Chap. 3 NECB 2015 Simple Trade-Off Path 2017 03 29 Above Grade Reference Building Proposed Building U Area Area x U U Area Area x U W/m²°C m² Req. W/m²°C m² Prov. ● Walls 0.247 252 62 0.240 231 55 ● Fenestration 1.900 144 274 1.700 165 281 ● Doors 1.900 4 8 1.900 4 8 ∑ Area x U 343 ꓿ 343 Max Area x U 343 - 288 ꓿ 55 Max Uw 55 ÷ 231 ꓿ 0.240 Copyright Conway Architect Inc.
- 38. SB-10 ASHRAE 189.1- 2014 Prescriptive Solution 90.1 2013 – 10% 2017 03 29 Copyright Conway Architect Inc.
- 39. SB-1037 NECB-15 + Div. 3, Chap. 3 vs. ASHRAE 90.1-13 + Div. 3, Chap. 2 vs. ASHRAE 189.1-14 2017 03 29 NON RESIDENTIAL 90.1-13 NECB -15 189.1-14 U U U Roofs • Insulation Above Deck 0.164 0.156 0.161 • Metal Buildinga 0.158 0.156 • Attic and Other 0.107 0.105 Walls, Above Grade • Mass 0.273 0.247 0.402 • Metal Building 0.256 0.251 • Steel Framed 0.250 0.246 • Wood Framed and Other 0.261 0.256 Below Grade • Below Grade Wall 0.284 0.284 0.462 • Below Grade Roof ? 0.284 ? Copyright Conway Architect Inc.
- 40. SB-1037 NECB-15 + Div. 3, Chap. 3 vs. ASHRAE 90.1-13 + Div. 3, Chap. 2 vs. ASHRAE 189.1-14 2017 03 29 NON RESIDENTIAL 90.1-13 NECB -15 189.1-14 Floors U U U • Mass 0.261 0.183 0.256 • Steel Joist 0.164 0.161 • Wood Frame & Other 0.138 0.136 Opaque Doors • Swinging 2.56 1.900 2.51 • Non-Swinging 2.56 2.51 Copyright Conway Architect Inc.
- 41. SB-1037 NECB-15 + Div. 3, Chap. 3 vs. ASHRAE 90.1-13 + Div. 3, Chap. 2 vs. ASHRAE 189.1-14 2017 03 29 NON RESIDENTIAL Chapter 2 Chapter 3 189.1 Fenestration U U U Vertical Fenestration FDWR 40% 37% (YOW) 40% • Nonmetal framing: all 1.64 1.90 1.61 • Metal framing: fixed 2.15 2.11 • Metal framing: operable 2.56 2.51 • Metal framing: Ent. Door 3.94 3.87 Skylights SRR 3% 5% 3% • Skylights 2.56 1.90 2.51 Copyright Conway Architect Inc.
- 42. SB-10 The beginning of the End • OAA PTs: www.oaa.on.ca/professional+resources/pr actice+tips+&+regulatory+notices/practice+ tips/36 • SB-10: www.mah.gov.on.ca/Asset15944.aspx?met hod=1 • ASHRAE 90.1 & 189.1: www.ashrae.org/standards-research-- technology/standards--guidelines • EE4: www.nrcan.gc.ca/energy/software- tools/7453 2017 03 29 Copyright Conway Architect Inc.
- 43. SB-10 Almost the End • IBR: ibr.ansi.org/Standards/Default.aspx#sdo • OBC Vol 1: www.ontario.ca/laws/regulation/120332 • Forms: www.buildrightontario.com/mmah/ • CAN-quest: www.nrcan.gc.ca/energy/efficiency/buildi ngs/eenb/16600 2017 03 29 Copyright Conway Architect Inc.
- 44. SB-10 the End? I certainly hope not. Questions? 2017 03 29 Image by Astronaut Ron Garan aboard ISS Copyright Conway Architect Inc.
Editor's Notes
- A little house keeping. BECOR sessions count for Structured OAA Con-Ed points so please make sure that Silvio has your information and we’ll send out certificates for uploading to OAA. I suggested that anyone who tuffs it out to the end of my presentation should get a bonus ½ hour but the OAA frowned on it. We are always looking to reach out to the broad construction community. It would help us to know how you heard of this session. Who is here as a result of our incessant emailing? How about through word of mouth? Did anyone hear about this through ORSA? Did anyone catch it on the OAA Con-Ed webpage? Lastly please set you phone airplane mode. If you are on call for the next few hours please set your phone to stun. So who spent Saturday night in the dark? You do know that this presentation is about energy conservation. My name is Gerry Conway. I’d like to get some idea of who’s here. Can I get a show of hands.
- Did I forget anyone? Robert is also an Engineer, at times a manufacturer, supplier, intrepid Artic Explorer. More lives than a cat. Proof there is good in us all. What is the level of familiarity with SB-10? Very, fluent? There are people here who could give this lecture Somewhat, conversant Totally Lost Hopefully we will have something for everyone.
- OAA Practice Tips are guides written by the OAA Practice Committee. They are intended to help Architects with topics that arise in the day to day practice. It’s been my privilege to service with the committees for the past 6 years. Practice Tips represent the collective wisdom of Ontario Architects with a wealth of experience, knowledge, skill and outstanding commitment. They are directed towards Architects but have great value to the broader construction community. To that end the OAA makes the PTs available to everyone.
- No need to login, Look under Professional Resources
- While doing the PT I was sorely tempted to order the variables into a memorable acronym but prudence got the better of me. You have no doubt realized this is an acronym rich presentation so please ask me if I wiz by one and you would like a translation. Oh and God forbid I make a mistake. I’ve long since come to terms with my limitations and fallibility so please don’t be shy.
- U = the contribution of all components including boundary layers. C is the same except it doesn’t include boundary layers and is usually used for below grade assemblies. In red are the changes necessary to bring this assembly into compliance with SB-10. .
- PPLs occur when you have any higher conductive component in the same plane as the insulation and includes studs, shelf angles and structural supports. Can anyone give me another example. Brick ties are also excellent conductors but the Code gives you a pass on their effect. RSI = m²•K ⁰/W? Now you know why engineers use U values. So how do we determine Effectives U and C values?
- This is the EE4 output or the previous assembly W5.01. Note the 50% reduction from total R value through the insulation to effective R value due to parallel path losses. EE4 is getting pretty old, but is very good, easy to use and is still available from although not supported by NRCan. It requires either a 32bit OS or Emulator like Virtual Box. Many manufacturers and interest groups like Owens Corning, Roxul or CWC provide Effective U value calculators but they typically have a bias. CWC ‘s calculator doesn’t offer steel studs as an option.
- Alternately you can look up the effective R in ASHRAE 90.1 Appendix A. These are IP R values. Note that on a 150 Steel Stud the efficacy of the insulation is reduced to approximately 1/3 of it’s nominal value.
- Ghosting. Would anyone like to offer an opinion on the cause? Likely caused by the steel stud temperature dropping below the DPT.
- In all Codes, glazing U values are effective U values. Some manufacturers, in this case Kawneer, provide charts to help you determine the effective U value based on CoG U and % of vision area. SB-10 requires an effective system U value for fixed metal framed fenestration of 2.15. If the design had 95% vision area, the required CoG U value would be 1.7 (0.30)or lower.
- Glass manufacturers like PPG offer a wealth of info on their products. Unfortunately it is often in imperial units only. To convert Usi 1.7 from the previous example to Uip you divide by my all time favorite conversion factor, 5.678, to get Uip 0.3. In this case all of the Solarban Low e, Argon filled IGU have Uip of 0.24, is below 0.3 and therefore exceeds the thermal transmission requirements. With SHGC below 0.4 and VT/SHGC ratio above 1.1 these units satisfy these requirements as well. You as the designer have many color, effect and reflectance choices within a double glazed 25mm unit.
- MNECB 1997 – 40% over 1997 performance levels in 20 years. Will we be carbon neutral by 2030? Canada is the # 4 on a per capita basis and the 9th largest GHG producer on earth. Maybe we need to up our game.
- Get some stickys! You have: A different numbering system, 3 current Divisions, 2 obsolete ones, Multiple chapters in each, Tables for 3 zones, Imperial and Metric versions of each and if that wasn’t bad enough, up until December 31st - 2 x the whole lot! If don’t get confused the first few times you use SB-10, there’s a future for you in Code review.
- For HDD18 use OBC SB-1. Ontario includes Zones 5, 6 & 7 from the banana belt SW of Belleville (Zone 5) to Big Trout Lake 7450 HDD18. Ottawa is a positively balmy 4500 HHD18. Determine the area of structural penetrations such as balconies, suspended and roof top equipment supports. These thermal bridges are limited to 2% of the exterior building envelope area, walls, roofs, exposed floors, doors and fenestration. Brick ties, flashings and intermediate structural connections are permitted thermal bridges. If penetrations exceed 2%, modelling is required.
- Record & distribute your design assumptions to all members of project team. Use your own form or MMAH Forms (being revised and likely appear on the Build Right Ontario site first). Review your design with M&E Consultants. Determine the best options for the project: Prescriptive or. Performance Solutions
- If the design building has 20% Fenestration then the reference building must have 20% Fenestration. Disclaimer: I wouldn’t want anyone to think that I am fluent with this software. If you can learn Revit this will be a piece of cake. Is anyone using the energy analysis tools in Revit? Be careful with the software. HDD may be based on ASHRAE Appendix C and not OBC SB-1, Check which energy code the software is using. ComCheck includes the 2012 version of SB-10. It has many other codes built in as well. Although the reference codes may be out of date, you can create a new reference building based on current SB-10 and compared your building to it.
- You cannot design the energy envelope under SB-10 Division 3 Chapter 2 without ASHRAE 90.1 nor can you design under Chapter 4 without NECB. You can buy 90.1 from ASHRAE on line for C$270. I couldn't fine the metric versions but I assume it’s out there somewhere. All versions of 90.1 are available for viewing for free on the ASHRAE Website. A word of warning! Over the years I’ve heard colleagues complain of how hard it is to read the Code. Well its got nothing on an ASHRAE standard. You’ll think the OBC read like a Tom Clancy novel after a few nights curled up with this. The good news is the envelope part, Section 5, after you throw out all the bits that SB-10 tell you to, is only 8 1/2 pages long. I encourage you to also become familiar with Sections 1-4 and Appendix A Browse the definitions as many are used in SB-10 and are not in the OBC. Appendix A, 40 pages, offers valuable explanatory info on the envelope part and some handy tables for determining effective U values. read only version for free at: https://www.ashrae.org/standards-research--technology/standards--guidelines/other-ashrae-standards-referenced-in-code
- Vestibules: Minimum 2.3m deep, and the lesser of 5m2 or 2% of Floor Area. Orientation: In 90.1-2013 fenestration on each of the West & East ≤ 25%. In 90.1-2010 AS ≥ AW & AS ≥ AE There are exceptions for the building or hill across the street, Higher SHGC trade-off.
- Storm windows ? Re-Roofing: In 2010 it could be interpreted as if you are replacing the membrane you had to replace and upgrade the insulation. 90.1- 2013 clarifies that you don’t.
- I don’t expect anyone to read it. I’ve put it in for illustrative purposes only. Changes? Well I guess the first thing is - its shorter. Skylights now have the same U value regardless of materials and there is one less note. Min VT/SHGC added to improve daylighting while not increasing SHGC And the critical change: they went from 3 to 4 significant digits. Really? Trust me, the prescriptive compliance process in SB-10, however pretentious, does not warrant 1/1000 of a W accuracy. This laser is likely 10mW. If I point it at the screen, that dot is 1/1000th of a W/m2. I concede that if I had a hundred of these pointed at you it would be a totally different storey.
- In SB-10 there is a chart for three climates zones, 5, 6 & 7, in both the imperial & metric. Conditioning categories, non-residential, residential & semi-heated, are in the first row. The column headings for the effective U & nominal R values for each conditioning categories are below. The first column lists the Construction Classes, Roofs, Walls, etc with the classes further broken down into subclasses, insulation above the deck, metal building, etc. The rows provide the values for the effective U & nominal R values of each of the subclasses.
- Standards have been updated CSA A440 2014, ASHRAE 189.1 2014, NECB 2015 etc.
- Until December 31 2017 you have a choice to use Division 3 Chapter 2 as it read in 2012 and the new tables issued in December 2016. Here is a comparison between the requirements expressed as a % change from the 2012 Division 2, Chapter 2. Legend: Green means there is a change with black & red numbers being positive & negative respectively.
- With fenestration the big changes are the addition of VT/SGHC ratio I believe in recognition of the value contribution of daylighting to energy conservation and the reduced performance requirements.
- If you chose to go the NECB route then get ready to fork over $250 or go out to the National Science Library. If anyone can find a free version online of this document please let me know.
- The significant differences between NECB and 90.1 solutions are: Allowable fenestration decreases from 40% to 20% depending on the number of HDD18. 90.1 permits 40% across the board. HDD15 is used for Walls, Roofs, SoG below grade separating semi-heated space. HDD18 & HDD15 values can be found under Notes at end of NECB Appendix C? Ottawa vs HDD18: 4500 vs HDD15: 3650 NECB uses the same values for all conditioning categories. Don’t get too excited about this. There’s not much difference in 90.1. Remember I mentioned the ridiculousness of 1/1000 W accuracy! No limits on where the glazing can go.
- NECB doesn’t do subclasses of construction. There are clear and potentially beneficial special provisions for semi-heated spaces. U/G roofs in semi-heated parking garages.
- Simple trade off method is just that ; simple. I’ve put this up to dispel the myth that Architects are Engineers who don’t do math. For those of us who may be a bit rusty, what this says is: the sum of the products of U x A for n assemblies of the proposed building must be less than or equal to that of the reference building. The reference building being in compliance with NECB prescriptive solutions.
- Imagine a 10m x 10m x 10m building in Ottawa where the designer wanted 45% high performance glazing on the South and 40% on each of the other 3 facades. You can not trade between vertical and horizontal classes of construction. The roof is the same in both the proposed and reference buildings so we need not factor that in. NECB limits the FDWR to 37%. The vertical surface area is 400m2. Allowable fenestration in the reference building is 148m2. The proposed building has = 165m2 or 41% (100m2 x .45) + (100m2 x .4 x 3) The designers pick PPG’s Solarban 70 XL, low e, argon filled IGUs, Pacifica Green with a CoG Winter U value of 1.37. The framing will be Kawneer 1600ss with 95% vision area. If I were to go back to the Kawneer chart, and I’m not, that all translates to a system U of 1.9 which through the grace of God meets Code. If it didn’t I would need to use a higher performance glass or framing system. Through the magic of Excel the number crunching looks a bit like this. As the table shows I would need to increase the wall performance the performance of W5.01 shown earlier by 2 ½ times. In other words increase the insulation from 76mm to 228mm. Probably not the way to go. What about improved glazing?
- If we changed the glazing to AGC Energy Select 73 or triple glazing with a CoG U =1.14 and the same framing & % vision area we end up with a glazing system U of 1.7. Now the wall system U is 0.24, below the design U of 0.247. We are good to go.
- Building Envelope is covered in Section 7 but there is a lot, a lot more to Green Buildings than just U, C, F & R values. However if you chose to go this route, take the values in 90.1-2013 and improve them by 10%.
- So how do they stack up? Here are the values from the 3 standards; 90.1, NECB and 189.1. In bold are the classes of construction values with the highest performance.
- Some useful websites. I’ve printed them up for anyone who is interested. If you must leave early there are some on the table at the door.
- IBR. The Americans are more progressive than we are. If a standard is referenced in law, it should be readily & freely available. If you go there you will find links to free ANSI, IEE, NFPA and more standards. I believ that such forward thinking gives them a competitive advantage.