new building energy code requirements for bc and...

NEW BUILDING ENERGY CODE REQUIREMENTS FOR BC AND VANCOUVER – DEC 2013

UDI, Vancouver, November 26th 2013 Blair McCarry P.Eng FASHRAE Hon AIBC LEED BD&C

1. The New Building Energy Code(s)

2. ASHRAE vs NECB 11

3. Compliance Paths

4. Summary

New Building Energy Code Requirements

THE NEW BUILDING ENERGY CODE(S)

WHAT DOES THE BUILDING ENERGY CODE COVER? Supplement to BCBC 2012 and VBBL

• Minimum energy efficiency standards for buildings • Address efficient design of building systems:

– Building Envelope – Mechanical – Service Water Heating – Lighting – Electrical Power – Energy Performance Path

• BCBC Current: ASHRAE 90.1-2004

• New Code: as per December 20th 2013, options for compliance

• ASHRAE 90.1-2010, or • NECB 11

• Ventilation Rates: ASHRAE (62.1-2001 excl. addendum N)

NEW BUILDING ENERGY CODE REQUIREMENTS BC Building Code – Part 3 Buildings

NEW BUILDING ENERGY CODE REQUIREMENTS New Vancouver Building By-Law (VBBL)

• VBBL Current: ASHRAE 90.1-2007

• New VBBL 2014: harmonized with BCBC

• Options for compliance (with conditions)

• ASHRAE 90.1-2010 • NECB 11

• Takes into effect December 20th 2013

• Ventilation Rates: ASHRAE (62.1-2001 excl. addendum N)

NATIONAL ENERGY CODE EVOLUTION MNECB to NECB 11

Model National Energy Code for Buildings

(MNECB 1997)

• Low adoption rate, only officially by few jurisdictions

National Energy Code for Buildings (NECB 11)

• Significant improvements over MNECB

• Aim to be: energy source neutral, building and construction type neutral, not codify economics

• BC first Province to adopt, others likely to follow

ASHRAE 90.1-2004 Current BC Energy Code ASHRAE 90.1-2007 Current CoV Energy Code, LEED 2009 base (-10%) ASHRAE 90.1-2010 New BC and CoV Energy Code Option, LEED V4 base (-10%)

ASHRAE 90.1-2004 Current BC Energy Code ASHRAE 90.1-2007 Current CoV Energy Code ASHRAE 90.1-2010 and NECB 11 New BC and CoV Energy Code Option

MNECB 1997

NECB 11

LEED AND ENERGY CODES Possible topic of confusion

• Buildings awarded based on energy cost savings over a Baseline code (%) • LEED 2009 Baseline code: MNECB, or ASHRAE 90.1-2007

• New design code: NECB 11 or ASHRAE 90.1-2010

• LEED V4 (Just Released) Baseline Code: ASHRAE 90.1 2010

LEED AND VENTILATION CODES Possible topic of confusion

• Ventilation: pay attention - LEED 2009 requires ASHRAE 62.1-2007 for prerequisite, new energy codes referencing ASHRAE 62.1-2001

– MURB Issue: LEED requires ventilation supplied directly to rooms • Duct to each bedroom or Fan Coil supplying all rooms • Supply just to corridor or to suite common area not allowed

– Ventilation rates 30-50% lower in ASHRAE 62.1-2007 compared to code

ASHRAE 90.1 VS NECB 11

ENVELOPE

AIR TIGHTNESS Mandatory Provisions

• Both codes mandatory requirements of “continuous air barrier”

• Max air leakage rates for windows and doors

(labeling required) • NECB 11 more stringent on air leakage rate

– Curtainwalls 30% less air leakage in NECB 11 vs ASHRAE – Skylights 80% less air leakage in NECB 11 vs ASHRAE

• VBBL requires for new homes 3.5 ACH at 50Pa • Compare to Passive house standard: 0.6 ACH at

50Pa

VESTIBULES Mandatory Provisions

• Exception removed in ASHRAE! • Now vestibule required for all buildings >1,000 ft2

(Vancouver climate zone)

• Exception still in NECB 11! (for Vancouver) • Not required for building less than 5 storeys in any area that

has fewer than 3500 heating degree-days (°C)

• A few general exceptions still apply:

• Building entrances with revolving doors, • Doors directly open from a space <3,000 ft2 separate from

building entrance (ASHRAE) • Doors in retail spaces < 2,000 ft2, or dwelling units (NECB

11)

• ASHRAE: Vancouver Climate Zone 5c (3000 < HDD < 4000)

• NECB 11: Vancouver Climate Zone 4 (HDD < 3000)

• New BCBC clarification: Climate Zone 4 to be used (for both ASHRAE and NECB 11 compliance)

• But in VBBL: Climate Zone 5 to be used for ASHRAE compliance (not NECB11)

ENVELOPE PRESCRIPTIVE PERFORMANCE Climate zone differences– potential point of confusion

ENVELOPE EXAMPLE

Prescriptive comparison, Vancouver examples

Assembly (non-residential)

Current BC Code: ASHRAE 90.1-2004 (climate zone 5)

New BC Code: ASHRAE 90.1-2010 (climate zone 4)

New VBBL Code: ASHRAE 90.1-2010 (climate zone 5)

New BC & VBBL: NECB 11 (climate zone 4)

Roof (insulation above deck)

R-15.9 R-20.8 R-20.8 R-25

Wall above grade Mass R-8.13 Steel-framed R-11.9

Wood-framed R-11.2

Mass R-9.6 Steel-framed R-15.6

Wood-framed R-11.2

Mass R-11.1 Steel-framed R-15.6

Wood-framed R-15.6

R-18

Wall below grade NR NR R-7.5 ci R-10

Slab on grade (unheated example)

NR NR NR R-7.5 min 4ft around perimeter

Window U-value U-0.46 to U-0.67 Non metal framing U-0.40 Metal framing (curtain wall)

U-0.50 Metal framing

(fixed/operable) U-0.55

Non metal framing U-0.35 Metal framing (curtain wall) U-

0.45 Metal framing (fixed/operable)

U-0.55

U-0.42

Glazing % Max 50% 40% 40% 40% (including doors)

NECB 11 more stringent overall

% GLAZING ALLOWED New Requirements

• Current BC Code – ASHRAE 90.1 2004 • 50% max • Based on envelope above ground plus envelope for conditioned

space below ground

• Current VBBL ASHRAE 90.1 2007

• 40% max • Based on envelope above ground plus envelope for conditioned

space below ground

• ASHRAE 90.1 2010

• 40% max • Based on envelope above ground plus envelope for conditioned

space below ground

• NECB 11 • 40% max windows and doors in Vancouver, Less in colder

climates • Based on area of envelope above ground

BALCONIES AND EXPOSED SLAB EDGES New Requirements

• Current BC Code – ASHRAE 90.1 2004 • Envelope elements <5% of area can be ignored

• Current VBBL ASHRAE 90.1 2007 • Balcony and slab edges to be included in overall envelope

insulation value. Other elements <5% of envelope area can be ignored.

• ASHRAE 90.1 2010

• Same as 90.1 2007 but VBBL allows only 1% envelope area can be ignored

• NECB 11

• Envelope elements <2% of area can be ignored

HVAC

HVAC PRESCRIPTIVE REQUIREMENTS Heating impact - NECB 11 vs ASHRAE 90.1-2010

• Heating equipment efficiencies higher for NECB 11 (boilers and furnaces)

– NECB 11 mid efficiency boilers 83-85% vs ASHRAE 80-82%

• NECB 11 has provisions for improved part-load

performance (smaller, multiple staged or modulating boilers)

• NECB 11 less stringent on ventilation heat

recovery, based on sensible heat only, not outdoor air flow %

• NECB 11 has provisions for indoor pool and ice

rink heat recovery

• Kitchen hoods – maximum flow rates, transfer air, VAV or heat recovery

• Elevators – controls, ventilation, and lighting

• Data Centers – Cooling units, EER’s

• New: VRF and Water-to-water heat pump requirements

• Demand controlled ventilation

HVAC PRESCRIPTIVE REQUIREMENTS New in ASHRAE 90.1-2010 vs 2004, and not covered in NECB 11

Will depend on building type and size

• NECB 11 generally higher heating equipment efficiencies

• ASHRAE more stringent on ventilation heavy buildings and heat recovery

• Labs, kitchens, data centers - ASHRAE more stringent requirements on ventilation and equipment

HVAC PRESCRIPTIVE REQUIREMENTS So which one is more stringent on HVAC side?

BC office average - example

Lighting 20% Space

cooling 4%

Fans + Pumps

11% Plugs 14%

Space heating

50%

Water heating

1%

LIGHTING & PLUGS

• Similar new requirements in NECB 11 and ASHARE 90.1-2010

• New requirement for minimum skylight fenestration area to be installed

• Daylight harvesting is required for side-lit and top-lit areas

• Multilevel photocontrol requirements – push for integrated design

DAYLIGHTING AND DESIGN Getting more emphasis in both codes

• Similar requirements in NECB 11 and ASHARE 90.1-2010

• Reduced Lighting Power Densities

• 10-44% reductions compared to previous BCBC (ASHRAE 90.1-2004)

• Significant shift for NECB 11 for efficiency

• Office MNECB: 1.8 W/ft2 • Office NECB 11: 0.9 W/ft2

LIGHTING POWER DENSITIES Whole Building Lighting Power Example

ASHRAE generally more stringent overall

• Occupancy control (NECB 11 and ASHRAE)

• Stairwell lighting (ASHRAE 90.1-2010)

• Garage lighting (ASHRAE 90.1-2010)

• Plug load controls (ASHRAE 90.1-2010)

LIGHTING AND PLUG LOAD CONTROLS Large impact on electrical savings

BC office average - example

Lighting 20%

Space cooling

4% Fans + Pumps

11%

Plugs 14%

Space heating

50%

Water heating

1%

Office Plug Loads at Night

COMPLIANCE PATHS

• Both have mandatory requirements

• Alternate compliance paths:

1) Meeting prescriptive requirements 2) Tradeoff option

• ASHRAE: envelope ONLY • NECB 11: envelope, lighting, HVAC,

SHW – individually 3) Building modeling for trade-offs

• NECB – energy based (kWh) • ASHRAE - energy cost based ($)

COMPLIANCE OPTIONS Always to be met

• BCBC: sign off from responsible architect/engineer/designer - one page Design Verification Reports

• VBBL: requires more involved checklists

• To go in with building permit applications, as per December 20th 2013

PERMIT PROCESS Varies between BCBC and VBBL

VBBL Checklist

SUMMARY

OPTION OF ENERGY CODE – WHICH ONE TO CHOOSE? NECB 11 performance over ASHRAE 90.1-2010, Vancouver Example

-5%

0%

5%

10%

15%

20%

0

50

100

150

200

250Energy use intensity (Kwh/m2)

NECB 2011 ASHRAE 90.1 2010 % Difference

ASHRAE generally lower energy But what about energy cost and GHG’s?

Source: NRC and Caneta Research Inc.

OPTION OF ENERGY CODE – WHICH ONE TO CHOOSE? NECB 11 performance over ASHRAE 90.1-2010, Vancouver Example

• NECB Insulation Levels are generally greater than ASHRAE • Meeting Envelope and Glazing % can be challenging

• % Glazing allowed by NECB is <ASHRAE as doors are

included and % glazing is reduced in colder climates

• Design Professionals more familiar with ASHRAE

• Suggest that ASHRAE will be used far more frequently than NECB

COMPLIANCE PATHS – ENERGY MODELING Quality of Energy Modeling Product

• Use of Energy Modeling will be significantly increased to offset envelope/glazing % requirements

• Quality of Energy Modeling is often not good across North America

• Seminars and Courses are being developed locally

• Be cautious about inexperienced and economical energy modelers as you may find out about problems late in project development

• CaGBC and BC Hydro have lists of experienced modelers

THANK YOU Blair McCarry P.Eng. FASHRAE Hon AIBC LEED AP BD+C

Senior Sustainability Consultant, Perkins+Will blair.mccarry@perkinswill.com