empowering design within the constraints of sb-10 design sb_10_ p… · empowering design within...

Steven Murray, P.Eng., PMP

Building Science Specialist

May 7, 2015

Empowering Design within the Constraints of SB-10

OVERVIEW - THE CONSTRAINTS

2

OBC requirements and the standards.

ASHRAE 90.1 prescriptive requirements and trade-off method for the envelope.

NECB prescriptive requirements and trade-off method for the envelope.

Summary of the prescriptive requirements - what is means in the context of OBC.

Looking at different methods of accounting for thermal bridging.

Performance Path in Practice – A compliance approach - interactive energy modeling.

1

2012 OBC REQUIREMENTS

3

PART 12 RESOURCE CONSERVATION

Section 12.1. General

12.1.1. Application

12.1.1.1. Scope

(1) The scope of this Part shall be as described in Subsection 1.1.2. of Division A.

12.1.1.2. Application

(1) This Part applies to resource conservation in the design and construction of

buildings.


4


Section 12.2. Energy Efficiency

12.2.1.2. Energy Efficiency Design Before January 1, 2017

(1) This Article applies to construction for which a permit has been applied for

before January 1, 2017.

(2) Except as provided in Sentences (3) and (4), the energy efficiency of all buildings

shall conform to Division 1 and Division 2 or 4 of MMAH Supplementary

Standard SB-10, “Energy Efficiency Requirements”


5

PART 11 RENOVATION


11.1.2. Application

11.1.2.1. Extension, Material Alteration or Repair

(1) Where an existing building is subject to extension, material alteration or repair,

(a) the proposed construction shall comply with Section 11.3., and

(b) the performance level of the building shall be evaluated and compensating

construction shall be undertaken in accordance with Section 11.4.

Talk to your Code specialist!

OBC SB-10 REQUIREMENTS

6

Division 1

General


1.1.1. Application of Supplementary Standard SB-10

1.1.1.3. Energy Efficiency Design after December 31, 2011

(1) Except as permitted in Sentence (2), the energy efficiency design and

construction of buildings required to comply with Sentence 12.2.1.2.(2)

of Division B of the Building Code shall comply with Division 3 of this

Standard.

OBC SB-10 REQUIREMENTS

7

1.1.1.3. Energy Efficiency Design after December 31, 2011

(2) Where the ANSI/ASHRAE/IESNA Standard 90.1, “Energy Standard for

Buildings Except Low-Rise Residential Buildings” is referenced in this

Standard, it shall be the edition designated in Table 1.3.1.2.

1.1.2.1. Energy Efficiency Design

(1) Except as provided in Sentence (2) and Article 1.2.1.1.

and except as permitted in Sentence (3), the energy

efficiency of all buildings shall be designed to:

(a) exceed by not less than 25% the energy efficiency

levels attained by conforming to the CCBFC, “Model

National Energy Code for Buildings.”

(b) exceed by not less than 5% the energy efficiency

levels attained by conforming to the

ANSI/ASHRAE/IESNA 90.1, “Energy Standard for

Buildings Except Low-Rise Residential Buildings”, or

(c) achieve the energy efficiency levels attained by

conforming to the ANSI/ASHRAE/IESNA 90.1, “Energy

Standard for Buildings Except Low-Rise Residential

Buildings” and Chapter 2.

SB-10 – DIVISION 3

8


9

Exceptions:

• Part 9, residential occupancy buildings

• Buildings with electric space heating


11

Compliance Paths:

CLIMATE ZONES

12

CLIMATE ZONES

13

ZONE 5:

Toronto, Windsor

Hamilton

ZONE 6:

Ottawa, Kingston

Kitchener, Waterloo,

London

PRESCRIPTIVE – ZONE 6

14

PRESCRIPTIVE – ZONE 6

15

R2.9

R2.2

STANDARDS IN CODES

16

ASHRAE 90.1 2004

ASHRAE 90.1 2007

ASHRAE 90.1 2010 & NECB 2011

ASHRAE 90.1 2010

17

WHO ARE THEY?

American Society of Heating Refrigeration and Air-conditioning

Engineers

WHAT IS THE STANDARD?

First addition developed in 1970

In 1999 the standard was put into continuous maintenance

Applies to all commercial buildings and MURBS greater than 3 stories.

ASHRAE 90.1 OVERVIEW

18

ALTERNATIVE PATHS FOR COMPLIANCE

Prescriptive

Trade-off

Energy cost budget

PRESCRIPTIVE PATH (OR TRADE-OFF) REQUIRE THAT ALL PARTS OF THE

STANDARD BE MET:

Part 5 - Building envelope

Part 6 - Heating, ventilating and air-conditioning

Part 7 - Service water heating

Part 8 - Power

Part 9 - Lighting

Part 10 - Other equipment Mandatory Provisions

ASHRAE 90.1 OVERVIEW

19

ASHRAE 2004 Baseline

ASHRAE 2007 Increased BE requirements

ASHRAE 2010 No major changes in BE requirements

NECB 2011

20

Developed by Natural Resources Canada & the National Research Council for Canada

What is the Standard? Last version was in 1997 (MNECB)

Design intent was to be roughly equivalent to ASHRAE 90.1 2010

Applies to new buildings (except part 9), additions to existing building, but silent on renovations

MNECB is referenced in LEED

NECB OVERVIEW

21

Prescriptive

Trade-off (simple or detailed)

Energy simulation (building energy compliance)

ALTERNATIVE PATHS FOR COMPLIANCE

Part 3 – Building envelope

Part 4 – Lighting

Part 5 – Heating, ventilating and air-conditioning systems

Part 6 – Service water heating systems

Part 7 – Electrical power systems and motors

PRESCRIPTIVE PATH (OR TRADE-OFF) REQUIRE THAT ALL PARTS OF THE STANDARD BE MET:

ASHRAE 90.1 2010 BUILDING ENVELOPE

ASHRAE 90.1- BUILDING ENVELOPE

25

THIS MEANS THAT THE BUILDING SHOULD BE DESIGNED TO MEET THESE PROVISIONS:

Insulation

Air leakage

• Air-barrier selection and design

• Limit to fenestration and doors including cargo doors

• Vestibule

Fenestration and Doors values

• NFRC

ASHRAE 90.1- MANDATORY PROVISIONS

26

ASHRAE 90.1 MANDATORY PROVISIONS

27

ASHREA 90.1 Air leakage

limits

NAFS Air Leakage

limits

ASHRAE Type Limit

Glazed Swinging entrance door & revolving doors

1.0 cfm/ft2 at 1.57psf

Curtain wall & Storefront 0.06cfm/ft2 at 1.57psf

Other products 0.2cfm/ft2 at 1.57psf or 0.3 cfm/ft2 at 6.24psf

NAFS defines air leakage by performance

class (R, LC, CW and AW) and air infiltration /

exfiltration levels (A2, A3 and Fixed) and can

be more stringent:

Fixed as low as 0.2 L/s.m2 at 300Pa (or 0.04cfm/ft2 at 6.24psf) Operable as low as 0.5 L/s.m2 at 300Pa (or 0.1cfm/ft2 at 6.24psf)

ASHRAE 90.1 PRESCRIPTIVE METHOD

28

THE PRESCRIPTIVE METHOD CAN ONLY BE

USED IF:

The vertical fenestration ≤ 40% of Gross wall Area

The skylight fenestration ≤ 5% of gross roof area

ASHRAE 90.1 - OPAQUE AREAS

29

For conditioned spaces the exterior building envelope shall comply with, either: the residential or the non-residential requirements in the tables

For semi-heated spaces the semi-exterior building envelope needs to comply with the requirements in the tables

ASHRAE 90.1 - PRESCRIPTIVE OPAQUE AREAS

30

THE TABLES CONTAINING THE THERMAL PERFORMANCE REQUIREMENTS ARE PROVIDED IN THE STANDARD, BY CLIMATIC ZONES, AND LOOK LIKE THIS:

For all opaque elements (except doors) compliance should be demonstrated by the following methods:

Maximum U-factors, C-factors or F-factors for the entire assembly

Minimum rated R values of insulation

Exception: For multiple assemblies within a single class of construction for a single conditioning space, weighed average can be used.

ASHRAE 90.1 PRESCRIPTIVE OPAQUE AREAS

31

Components

Zone 5

Non-Residential Residential Semi-Heated

U factor R value U factor R value U factor R value

Roof - insulation above deck

0.048 (R20.8)

20.0c.i. 0.048 (R20.8)

20.0c.i. 0.119 (R8.4)

7.6c.i.

Roof - Attic 0.027 (R37.0)

38.0 0.027 (R37.0)

38.0 0.053 (R18.9)

19.0

Walls - Mass 0.090 (R11.1)

11.4c.i. 0.080 (R12.5)

13.3c.i. 0.151 (R6.6)

5.7c.i.

Walls - Steel framed 0.064 (R15.6)

13.0+7.5c.i. 0.064 (R15.6)

13.0+7.5c.i. 0.124 (R8.1)

13.0

Walls - Wood framed 0.064 (R15.6)

13.0+3.8c.i. 0.051 (R19.6)

13.0+7.5c.i. 0.089 (R11.2)

13.0

ASHRAE 90.1 PRESCRIPTIVE - OPAQUE AREAS

32

SO THAT MEANS:

If there is more than nails or screws going through the insulation, it is not continuous

If there are studs, girts, clips, even brick ties they need to be accounted for.

This can be done by calculating the effective U (or R) values of these assemblies


33

NOMINAL R VALUES

Rated R values which do not take into account framing or other element interrupting the insulation

Calculated R values which allows for the impact of thermal bridges

EFFECTIVE R VALUES vs.


34

Zone 4&5 = 0.064


35 Zone 5 = 0.051 Zone 4 = 0.064

36

Components

Residential

R values

Zone 4 Zone 5 Zone 6 Zone 7 Zone 8

Roof - insulation above deck

20.0c.i.

20.0c.i. 20.0c.i. 20.0c.i. 20.0c.i.

Roof - Attic 38.0

38.0 38.0 38.0 49.0

Walls - Mass 11.4c.i.

13.3c.i. 15.2c.i. 15.2c.i. 25.0c.i.

Walls - Steel framed 13.0+7.5c.i.

13.0+7.5c.i. 13.0+7.5c.i. 13.0+15.6c.i. 13.0+18.8c.i.

Walls - Wood framed

13.0+3.8c.i.

13.0+7.5c.i. 13.0+7.5c.i. 13.0+7.5c.i. 13.0+15.6c.i.


ASHRAE 90.1 PRESCRIPTIVE - FENESTRATION

37

Windows <40% of gross wall area and Skylights <5% gross roof area

All fenestration compliance shall be demonstrated through meeting:

• U factor no greater than the prescriptive requirements

• SHGC no greater than the prescriptive requirements

If there are multiple assemblies, compliance shall be based on an area-weighted average U-factor or SHGC (for a single space-conditioning and within a single class of construction).

The SHGC can be reduced using a multiplier when a permanent projection provides shading for the window

ASHRAE 90.1 PRESCRIPTIVE - FENESTRATION

38

Components

Zone 5

Residential Non-Residential Semi-Heated

U factor SHGC U factor SHGC U factor SHGC

Non-Metal Framing 0.35

0.40 for all

0.35

0.40 for all

1.20

0.40 for all

Metal Framing (curtain wall and storefront) 0.45 0.45 1.20

Metal Framing (entrance doors) 0.80 0.80 1.20

Metal Framing (operable and fixed windows, non-entrance doors) 0.55 0.55 1.20

Skylight (glass, without curb)

0-2% 0.69

0.49 0.69

0.49 1.36

NR

2-5% 0.39 0.39 NR

ASHRAE 90.1 TRADE-OFF

39

The trade-off method allows greater flexibility when some of the building envelope components are not meeting:

• The basic requirements for the Prescriptive method (e.g. > 40% window to wall ratio and/or >5% skylight to roof ratio)

• The prescriptive R or U values

• Trade-offs are made between any building envelope components (but just building envelope component)

• It implies that some of the building envelope components exceed the minimum requirements

• Schedules of operation, lighting power, equipment power, occupant density, and mechanical systems need to be the same for both the proposed building and the base building


40

THE BUILDING ENVELOPE COMPLIES WHEN:

Envelope performance

factor of proposed building

Envelope performance

factor of base building ≤

The base building is a building that has 40% fenestration to gross wall area and for which all BE components meet the prescriptive minimum U value

The envelope performance factor is calculated using the information contained in normative appendix C


41

Need to : Do take-offs for all the different BE

components i.e. floor, roof, wall and fenestration assemblies for every space-conditioning category and every orientation.

Evaluate the U values of each component including SHGC and VT for fenestration.

Enter all the numbers into a series of equations that you can find in normative Appendix C*.

COMcheck (Now has Canadian climate data). *

Axis – Raymond Letkeman Architects

NECB 2011 BUILDING ENVELOPE

NECB

43

NECB - MANDATORY PROVISIONS

44

NO SPECIFIC MANDATORY PROVISIONS

But more specific than ASHRAE on how to deal with effect of structural members that may

partially and completely penetrate the envelope

In the prescriptive requirements, we find that :

Insulation should be installed in a manner that avoids affecting its R value (convection, wetting, etc.).

Insulation value required depends on zone, assembly (wall, roof or floor) and location (above or below grade or spaces heated to different temperature)

Air leakage should be controlled, including at fenestration and doors, which have limits of air leakage allowable

A vestibule is likely required

NECB - PRESCRIPTIVE METHOD

45

THE PRESCRIPTIVE METHOD CAN ONLY

BE USED IF:

FDWR ≤ 0.40 for HDD < 4000 FDWR ≤(2000- 0.2*HDD) 3000 for 4000 ≤ HDD ≤ 7000 FDWR ≤ 0.20 for HDD > 7000

The skylight fenestration ≤ 5% of gross roof area

&

NECB - THERMAL BRIDGING

46

THERMAL BRIDGING CREATED BY STRUCTURAL

MEMBERS

The thermal bridging effect of closely spaced repetitive structural members (e.g. studs) and of ancillary members (e.g. sill and plates) should be

taken into account.

The thermal bridging of major structural elements that are parallel to the building envelope can be ignored, provided that they do not increase the thermal transmittance to more than twice than

permitted.

The thermal bridging of major structural elements that must penetrate the building envelope need

not be taken into account, provided that the sum of the areas is less than 2% of the above ground

building envelope.

Service equipment, shelf angle, ties and associate fasteners as well as minor structural members need not be taken into account!!!

NECB PRESCRIPTIVE INSULATION

47

The prescriptive method requires:

W

4xW W

4xW

NECB PRESCRIPTIVE WALLS ABOVE GRADE

48

Assemblies

Any Occupancy

R values (effective)


Walls 18 20.4 23 27 31

Roofs 25 31 31 35 40

Floors 25 31 31 35 40

Walls - mass 11.4

Walls - steel framed 15.6

Walls - wood framed 19.6

No difference between residential

and non-residential

No difference between the different

type of construction

Roofs - insulation above 20.8

Roofs - attic 37.0

NECB PRESCRIPTIVE FENESTRATION AND DOORS

49

Components U values (effective)


All Fenestration 0.42 0.39 0.39 0.39 0.28

All Doors 0.42 0.39 0.39 0.39 0.28

No difference between residential and non-residential

No difference between the different type of assemblies

No SHGC requirements

Exceptions: Skylights that represent < 2% of gross roof area can have a

thermal transmittance of no more than 0.60

Doors that represent < 2% of gross wall area can have a

thermal transmittance of no more than 0.77

Non-metal 0.35

Metal framing (CW) 0.45

Metal framing (others) 0.55

Entrance doors 0.80

Skylights 0.58

NECB - PRESCRIPTIVE METHOD

50

NECB - TRADE-OFF METHODS

51

THERE ARE 2 TRADE-OFF PATHS:

Simple trade-off calculations

Detailed trade-off path

Proposed Bldg Envelope Annual Energy Consumption

Reference Bldg Envelope energy target

≤

Calculation are done using an energy model with set requirements

Proposed building

Reference building

≤

NECB - DETAILED TRADE-OFF METHOD

52

THE DETAILED METHOD CONSISTS OF:

Same building size and shape, roof slope, and building orientation for the proposed and reference building

Same assumptions for space heating and cooling

Allowable fenestration and door areas in the proposed building can be varied, while it is set per the prescriptive requirements in the reference building

Take into account thermal mass and SHGC

Air leakage and solar absorbance cannot be varied

COMPARISON OF THE 2 STANDARDS

COMPARISON OF 2 STANDARDS

54

ASHRAE 90.1 2010 NECB 2011

Mandatory requirements

Yes, for all methods Not for energy modeling

Prescriptive requirements

Generally less demanding R values

Stringent, specific

• Framing Take into account Take into account

• Structure Not clear Specific (if this then…)

• Cladding attachments Take into account Some can be ignored

• Service penetrations Ignore Specific (if this then…)

• Walls More categories Less categories

• Fenestration & doors More categories Less categories

Trade-off methods Complex, no benefit if FDWR <40%

Simple or software Benefit if FDWR <40%

OVERALL

55

Prescriptive method, for either standard, is for

simpler buildings

Trade-off method may get you the desired result, but cannot do

anything for you when most of the BE components are below

CONCLUSION REGARDING THE STANDARDS

56

Wood frame is well suited for prescriptive but: New standards will generally require exterior insulation to meet the

max U-factor with 2x6 residential Only zone 4 in ASHRAE (but not in NEBC) could do without exterior

insulation in residential For non-combustible building, the prescriptive method is not a likely

candidate This is especially true for buildings with high window/wall ratio Exterior insulated assemblies can probably meet it but structure

penetrating through (balcony slabs, parapet, etc.) need to be taken into account

The trade-off methods is an option NECB simplified is the easiest but not necessarily best You need to have something to trade off with Glazing ratio has the biggest impact and it is hard to make up for it with

insulation

CONSTRAINTS GET TIGHTER SB-10 2017

OBC REQUIREMENTS AFTER 2016

58


Section 12.2. Energy Efficiency

12.2.1.2. Energy Efficiency Design After December 31, 2016

(1) This Article applies to construction for which a permit has been applied for after

December 31, 2016.

(2) Except as provided in Sentences (3) and (4), the energy efficiency of all buildings

shall,

(a) be designed to exceed by not less than 13% the energy efficiency levels

required by Sentence 12.2.1.1.(2), or

(b) conform to Division 1 and Division 3 or 5 of MMAH Supplementary Standard

SB-10, “Energy Efficiency Requirements”.

25% 25% 25%

~34%

2012 2013 2015 2017

Energy Efficiency (above MNECB 1997)

SB10

OBC REQUIREMENTS AFTER 2016

WHAT DOES 2017 CODE COMPLIANT LOOK LIKE?

60

Shift from wall R-value thinking to whole building R-value

Look to building envelope to achieve energy gains

Plan by defining options early and analyzing

Be prepared to evaluate new products

A LOT LESS GLASS

UNLESS BUILDING ENVELOPE ENERGY

EFFICIENCY IMPROVES

FROM BAD TO BETTER

61

EFFECTIVE R VALUES

Computer Modeling

Hand Calculations Series calculation method Parallel path calculation method Isothermal planes method

Lab Measurement

CONSIDERING THERMAL BRIDGING

63

L2,par

apet

Lro

of

HEAT LOSS

64

AREA WEIGHTED AVERAGE (SAME CLASS)

65

R1.25 for 9” slab edge

R15 for 8’3” wall

1

𝑅=

0.75 × 11.25 + 8.25 × 1

15

9

𝑅 ≅ 7.8

3D MODELING

66

Time-transient dynamic 3D heat transfer model that is capable of accurately modeling:

Complex geometries

Radiation through air spaces

Radiation to the interior and exterior space

Conduction of small areas of highly thermal conductive materials through larger areas of highly insulating materials

Calibrate the model using existing lab testing

WHERE TO FIND INFORMATION

67

Resource material ASHRAE 90.1 Appendix A

BE THERMAL BRIDGING GUIDE

68

ASHRAE 90.1 does not

address major thermal

bridges such as slab

edges, shelf angles,

parapets, flashings at

window perimeters, etc.

In practice, these details

are largely overlooked.

WHAT IS THE GUIDE

69

Started with AHSRAE 1635RP project

when linear transmittance got

introduced to North America

BE Thermal Guide looked at over 400

details familiar to the BC MURB market

including:

CONCEPTUAL LEAP

70

Types of Transmittances

Clear Field Linear Point

oUpsi chi

LINEAR TRANSMITTANCE

71

Additional heat loss

due to the slab

oQQ slabQ

OVERVIEW OF THE GUIDE

72

Introduction

Part 1 Building Envelope Thermal Analysis

(BETA) Guide

Part 2 Energy and Cost Analysis

Part 3 Significance, Insights, and Next Steps

Appendix A Material Data Catalogue

Appendix B Thermal Data Catalogue

Appendix C Energy Modeling Analysis and Results

Appendix D Construction Costs

Appendix E Cost Benefit Analysis

RESULTS – APPENDIX B

73

HOW MUCH EXTRA LOSSES CAN DETAILS ADD?

74

Mass wall with R-12 insulation inboard Steel stud with R-10 exterior insulation and horizontal girts at 24”o.c and R-12 in the stud cavity

Standard 90.1 Prescriptive Requirements for Zone 5 Non-

Residential Mass Wall, U-0.090 or R-11.4 ci

Steel-Framed Wall, U-0.064 or R-13 + R-7.5 ci

EXAMPLE BUILDING

75

Mass Concrete Wall Exposed concrete slab

Un-insulated concrete parapet

Punched window in concrete

opening

Steel-Framed Wall Exterior insulated structural steel

floor intersection

Insulated steel stud parapet

Punched window in steel stud

opening with perimeter flashing

10 floors

20% glazing

No Balconies

Standard details

IMPACT OF DETAILS

76

Transmittance Type

Mass Concrete Wall Exterior Insulated Steel Stud

Heat Loss (BTU/hr oF)

% of Total Heat Loss

(BTU/hr oF) % of Total

Clear Wall 118 52 % 98 67 %

Slab 92 40% 24 17 %

Parapet 9 4% 4 3 %

Window transition 8 4% 19 13 %

Total 227 100 % 145 100 %

IMPACT OF DETAILS

77

Performance Metric

Mass Concrete Wall Exterior Insulated Steel Stud

ASHRAE

Prescriptive

Requirements

Overall

Performance

ASHRAE

Prescriptive

Requirements

Overall

Performance

U

(Btu/hrft2oF) 0.09 0.14 0.064 0.091

“Effective” R

(hr ft2 oF/BTU) R-11 R-7 R-15.6 R-11

% Difference 44% 35%

IMPACT OF DETAILS

78

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

Ad

dit

ion

al C

on

trib

uti

on

to

Sp

ace

He

atin

g En

erg

y (G

J/m

2 o

f Fl

oo

r A

rea)

Clear Wall Only Including Poor Details Including Efficient Details

More

Insulation is

not the silver

bullet

Details can

have a

greater

impact

CONCLUSION

79

Details such as slab

penetration are easy to

account for in calculation

Codes do not yet take into

account details such as

window transitions

It will likely become

increasingly more difficult to

ignore thermal bridging at

intersections of assemblies

Move beyond simply adding

“more insulation”

EMPOWERING DESIGN

80

FIND THE EFFICIENCIES

OVERCOME THE CONSTRAINTS

MAINTAIN THE DESIGN FLEXIBILITY

AND CREATIVITY

STRATEGICALLY USE NEW

PRODUCTS BASED ON ENERGY

SAVING AND COST BENEFIT

UTILIZE NEW TOOLS TO ANALYZE

OPTIONS EARLY

THANK YOU

STEVEN MURRAY, P.ENG., PMP [email protected]

905.319.6668

May 7, 2015

Empowering Design within the Constraints of SB-10

empowering design within the constraints of sb-10 design sb_10_ p… · empowering design within...

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