Compliance – Three Options

1. Prescriptive Approach

2. Performance Approach

3. Simple Trade-Off Method (STOM)

Section 9.36 of the NBC

Compliance With 9.36 – Three Options

1. Prescriptive Approach- Use prescribed RSI values and equipment performance

requirements listed in Section 9.36.

- Advantages: easy to use, acceptance by code authorities.

- Disadvantage: lack of flexibility.

Compliance With 9.36 – Three Options

2. Performance Approach- Model house and verify that its annual energy use does not

exceed that of an equivalent structure designed to 9.36.

- Advantages: very flexible, virtually any type of house or design detail can be modeled.

- Disadvantages: Time and cost plus availability of trained personnel.

2. Performance Approach (con’t)

● Intended for situations where major departures from the prescriptive requirements are planned, and which can not be accommodated with the STOM.

● Using HOT2000, or an equivalent computer model, the house’s energy performance is modeled under two conditions:

a) Designed to the prescriptive requirements b) Designed as is

● The energy consumption of House b) can not exceed that of House a).

● Default values for the house’s operating conditions (temperatures, occupancies, mechanical ventilation rates, base loads, etc.) are strictly controlled.

Compliance With 9.36 – Three Options

3. Simple Trade-Off Method- Use higher-than-required RSI values in one building

component and lower-than-required RSI values in another component (e.g. trade between walls and attics).

- Advantage: relatively quick and easy to use.

- Disadvantage: Acceptance by code authorities, technical issues with truss attics.

Simple Trade-Off Method

Opaque-to-Opaque Trades- Example: Reduce wall RSI level and increase attic RSI

level.

Opaque-to-Transparent Trades- Example: Reduce window RSI level and increase attic

RSI level.

Opaque-to-Transparent Trades - Intended for factory-constructed buildings.- Example: Reduce window area and reduce attic RSI level

How Reality and the Simple Trade-Off Method View An Attic Trade

Cost Impact Of Section 9.36

● Incremental costs of complying with 9.36 will be estimated.

● However, the provisions are not required to meet any cost-effectiveness requirement.

● The new 9.36 requirements were established to meet a pre-defined ERS target – not on the basis of some economic metric.

Cost Impact Of Section 9.36 (con’t)

● Incremental Cost of an Energy Conservation Measure= (Unit cost) x (Area or number) x (Utilization Factor)

● For example: The incremental cost of upgrading exterior wall insulation in Toronto from RSI 2.93 (R-20 nominal) to RSI 3.30 (R-24 actual) is:

= ($2.14 /m2) x (133.5 m2) x (1)= $285

Cost Impact Of Section 9.36 (con’t)

● Incremental Cost of an Energy Conservation Measure= (Unit cost) x (Area or number) x (Utilization Factor)

● For example: The incremental cost of upgrading the airtightness of a house in Toronto:

= ($2116/house) x (1) x (0.17)= $360

Costing Airtightness – The Problem

● 9.36 will contain approx. 10 prescriptive details for sealing the envelope. Total cost of all 10 measures ranges from $2000 to $3000.

● 9.36 is predicated on an airtightness of 2.5 ac/hr50.

● But, recent NRCan studies have shown that the average airtightness of new, non-program houses ranges from 2.3 to over 6 ac/hr50, depending on location.

● So, how much will the 9.36 measures add to the cost of the house?

Costing Airtightness – The Solution

● Using the location’s average airtightness, costs were prorated based on how much the airtightness has to be improved from the existing value to 2.5 ac/hr50.

● Results: Estimated costs to upgrade from existing practice

to 2.5 ac/hr50

Vancouver $ 652Toronto $ 360Montreal $ 292Winnipeg $ 0Fort McMurray $ 498Yellowknife $ 2900

Preliminary Building Envelope Costs

● Using this approach, the preliminary estimated incremental costs of upgrading to the proposed 9.36 requirements are:

Vancouver $ 951Toronto $ 1068Montreal $ 1001Winnipeg $ 1394Fort McMurray $ 1942Yellowknife $ 9229

Any More Questions??