Efficiency Canada’s comments on both the National Energy Code for Buildings (NECB) and National Building Code (NBC)

Submission to the National Research Council (NRC) of Canada for the public review period of the Model Codes

March 13, 2020

Policy Work | Submission

The public review period for both the National Energy Code for Buildings (NECB) and National Building Code (NBC) (“the Model Codes”) closed this past March 13th.  The proposed Model Codes represent an important step towards Canada’s PCF commitments and low-carbon energy future, they will also play a critical role in the future of Canada’s buildings sector.  

Efficiency Canada believes that these Model Codes are an opportunity to deliver innovative clean technology, generate employment in the clean-energy economy and help position the buildings sector as a leader in Canada’s transition to a low-carbon future. 

We commend the efforts of the codes community and we are pleased to have had the opportunity to comment on the 2020 Model Codes.  

The following are Efficiency Canada’s specific comments and feedback on proposed changes to NBC 2015 and NECB 2017.

National Energy Code for Buildings (NECB) comments

PCF 1527 – Tiered Code – General 

Efficiency Canada supports this proposed changeas is with comment(s). 

Efficiency Canada supports the proposed introduction of a Tiered Code in PCF 1527 as a path of incremental energy efficiency improvements leading to NZER by 2030, the governments’ clearly stated objective as committed to in the Pan-Canadian Framework for Clean Growth and Climate Change.   

Efficiency Canada encourages an emphasis placed on supporting the implementation of the NECB 2020 that will contribute to capacity in areas such as airtightness testing, building envelope design and building science. Contributing training and education in building envelope design and building science in every aspect of the buildings sector – trades, designers, architects and building officials – will help to ensure the Canadian market is well-prepared to reach advanced tiers of NECB 2020 

PCF 1409 – Update to NECB Application Statements 

Efficiency Canada supports this proposed change as is with comments. 

Efficiency Canada supports PCF 1409 given that the energy efficiency measures taken at the time of construction are long-term efficiency conservation measure that affect the building through a large part of its lifecycle. This proposed change makes clear that a building is not considered complete until it is whole. As a result, the intended energy efficiency measures of the NECB are more likely to be implemented as intended and the intent of the NECB, including prescriptive requirements for finishes such as lighting, HVAC equipment and more, will not be  undermined or violated. 

Efficiency Canada suggests that a mechanism be added to the NECB to address modifications to “shell” buildings that allows such buildings to be built and modified within the intent of the NECB (similar to ASHRAE Standard 90.1 see below) or as a separate standard within the forthcoming building code for existing building renovations (Alterations for Existing Buildings). 

From intro to ASHRAE Standard 90.1:

This standard provides:

a. Minimum energy-efficient requirements for the design and construction, and a plan for operation and maintenance of:

  • new buildings and their systems,
  • new portions of buildings and their systems,
  • new systems and equipment in existing buildings, and
  • new equipment or building systems specifically identified in the standard that are part of industrial or manufacturing processes

1414 – Whole building airtightness testing

Efficiency Canada support this proposed change as is with comments.

We support whole building air tightness measures that are part of the NECB’s envelope first approach to energy conservation. These measures are the most effective and long-lasting energy conservation measures and result in the most local economic spin-off. Other benefits include comfort and health for residents, as well as building resilience during power outages.

We applaud the implementation of air leakage testing in the proposed Tiers as it will allow industry time to successfully adapt to the process and meet the necessary requirements.

We suggest Codes Canada develop best practices materials that offer builders guidance in assembling the interfaces of different opaque building assemblies and components in order to ensure high levels of airtightness in the air barrier system of the whole building. Refer to the BC Energy Step Code’s Illustrated Guide — Achieving Airtight Buildings as an example.

National Building Code (NBC) comments

PCF 1608 — Alignment with ERS  

Efficiency Canada supports this proposed change with modifications. 

Related to the intent of PCF 1608 to align 9.36.5 with the ERS, the proposed change to 9.36.5.3. in PCF 1620 states that the intention of PCF 1620 is to allow the ERS to be used for both the proposed and reference house for code compliance. 

If so, then section 9.36.5.2 should clearly state that ERS is an acceptable modelling framework for the proposed and reference house. Efficiency Canada recommends that section 9.36.5.2 clearly state that the ERS is an acceptable way to model the proposed and reference house as follows:

For the purpose of this Subsection, the term “reference house” shall mean:

  • a hypothetical replica of the proposed house design using the same energy sources for the same functions and having the same environmental requirements, occupancy, climatic data and operating schedules, but made to comply with all applicable prescriptive requirements of Subsections 9.36.2. to 9.36.4; or
  • The reference house generated by HOT2000 in accordance with the EnerGuide rating system

For the purpose of this Subsection, the term “proposed house” shall mean:

  • a modelled replica of the actual house under consideration, in which some elements covered in Subsections 9.36.2. to 9.36.4. are specific to the actual house, while other elements not covered in those Subsections, but that are necessary to the calculation of the annual energy consumption, are assigned default values; or
  • a modelled replica of the actual house in accordance with the EnerGuide rating system.

PCF 1620 — ERS Compliance 

Efficiency Canada supports this proposed change as is with modifications 

Efficiency Canada suggests clarifying that the intent of 9.36.5.3 (1) (a) is to provide the ERS as an alternative to sections 9.36.5.4 to 9.36.5.16. As currently written, it is not clear that using the ERS replaces the need to comply with these sections. Efficiency Canada suggests that 9.36.5.3.1 (a) which says this Subsection, or” be replaced with “9.36.5.4 to 9.36.5.16, or” 

More generally, if using the ERS is an option per the change to 9.36.5.3 (1), it is unclear why the detailed modelling sections (9.36.5.4- to 9.36.5.16) continue to be included in this proposed changeGiven that energy modelling will be carried out by Energy Advisors familiar with the ERS it is unlikely that a builder or designer would take the more complicated path of manually creating a model that meets all the expectations of 9.36.5.3. (1) (a) instead of using the ERS per 9.36.5.3. (1) (b). Efficiency Canada suggests that the Committee use this opportunity to clarify this section and simplify the code by removing these modelling sections (9.36.5.4- to 9.36.5.16) and solely reference the ERS. 

PCF 1597 —  Service Water Heating Equipment Efficiency Table 

Efficiency Canada supports this proposed change with modifications. 

In PCF 1597, Table 9.36.4.2. Service Water Heating Equipment Performance Requirements more points are assigned to the less efficient, GHG emission intensive storage and tankless options. From an energy conservation and emissions standpoint, this does not make sense.  

Efficiency Canada suggests that higher levels of energy conservation points be assigned to more efficient Heat Pump Water Heaters than to less efficient, higher GHG emission storage/tankless water heaters.  

PCF 1610 

Efficiency Canada supports the proposed change as is with comment(s). 

The envelope first approach taken in PCF 1610 results in higher thermal resistance measures that are the most effective and long-lasting energy conservation measures and a source of good local jobs. Other benefits include comfort and health for residents, as well as building resilience and durability 

While Efficiency Canada recognizes that introducing a requirement for airtightness testing without a reporting requirement at Tier 1 is an important step towards building capacity in the Energy Advisor field, Efficiency Canada urges the Committee to require that the airtightness testing outcome be submitted to NRCan for data collection. This would enable the development of a national dataset of the energy performance of Canadian homes. 

Efficiency Canada also urges more stringent airtightness performance values at all tiers be considered, in this 2015-2020 code cycle and beyond. From a feasibility and financial standpoint, it is much more beneficial to implement a higher efficiency building envelope at the time of construction than to make changes later in the building lifecycle. 

PCF 1617 – Baseloads

Efficiency Canada supports this proposed change with comment(s).

Section 9.36.6.3 (3) states:

The overall energy performance improvement of the proposed building shall be calculated by subtracting the annual energy consumption of the proposed building from the house energy target and dividing the result by the house energy target.

Calculation of the energy performance targets appears to exclude baseloads in both the reference and proposed building. If this is the case, Efficiency Canada suggests considering adding language to make it explicitly clear that baseloads are to be excluded from the calculation.

PCF 1617 — The building envelope metric 

Efficiency Canada supports this proposed change with modifications. 

The building envelope metric, or “Percentage Improvement of Energy Performance of Building Envelope of Proposed Building Compared to Energy Performance of Building Envelope of Reference Building,” is not a measurement of building envelope performance. It is a measure of space heating energy reduction, and factors in space heating system efficiency. 

The proposed building envelope target calculation is defined in 9.36.6.3 (4):

[9.36.6.3.] Energy Performance Improvement Compliance Calculations

[4] The energy performance improvement of the building envelope of the proposed building shall be calculated by subtracting the annual energy consumption of space-heating systems and equipment in the proposed building from that of the reference building and dividing the result by the annual energy consumption of space-heating systems and equipment in the reference building.

As written, Section 9.36.6.3 [4] includes space heating system efficiency, is not appropriate for an “envelope metric.” Auxiliary energy required should not include space-heating systems and equipment in the reference or proposed buildings.  

The building envelope target as currently written does not differ significantly from the Overall Energy Performance Improvement metric. The space heating category offers the most effective energy efficiency savings with the notable exception being water heating measures such as heat pump water heaters and DWHR 

A more pressing issue is that by not including a building envelope target the tiered code is set up for failure by enabling builders to reach lower tiers easily with heat pump technology while not spending time in the early years of the code lifecycle developing designs and best practises around building envelope improvements, which will be required to achieve top-tier (net zero-ready) performance. Building net-zero ready homes will require changes to the way homes are currently built, and a stepped code allows for incremental change over time. However, if the code is structured such that the building envelope improvements associated with net zero building can be delayed until the last years of code implementation/last steps of the code, this will result in an abrupt change in code requirements at the end of the code cycle. 

Efficiency Canada recommends that calculation of the building envelope metric be revisited. The core considerations of any envelope calculations should be that envelope performance is separated from the performance of mechanical equipment, rational choices in building systems are encouraged, and that calculations are relatively simple for code users to apply.  

Efficiency Canada suggests adjusting the calculation methodology so that: 

  1. the outcome of the calculation is not affected by the space heating system  
  2. a separate model is not required to perform the building envelope target calculation, i.e. all calculation inputs can be extracted from the HOT2000 file for the proposed home 

A single-model solution could include using standard HOT2000 outputs such as “Auxilary Energy Required” or “design heat loss.”

PCF 1611 – Prescriptive path

Efficiency Canada supports this proposed change with modifications.

As written in PCF 1611 there will four separate compliance options in 9.36.1.3. Two prescriptive options (a and c), two performance options (b and c), and the NECB. Efficiency Canada suggests removing the prescriptive option 9.63.1.3 (a).

While Efficiency Canada believes that a performance-based approach to enhancing building performance to be the best approach Efficiency Canada recognizes that the prescriptive path outlined in PCF 1611 offers a continuation of the status quo for some builders.

However, prescriptive paths are difficult to apply on a national scale, or even a provincial scale, that is comprised of many different climate zones. Prescriptive paths are ill-suited to the complex and interconnected demands of modern buildings. Properly managing heat, air flows, pressures, moisture, and key system interactions is critical for a successful and cost-effective high-performance building and prescriptive codes are highly challenged to the needs of a complex and interconnected building-as-a-system.

Attempting to achieve aggressive energy performance with prescriptive building codes is more likely to stifle innovation and cost-optimal solutions. For these reasons, Efficiency Canada urge the Committee to abandon their stated intention to add the remaining upper tiers of the prescriptive path and instead focus on providing supports that facilitate a transition to the performance path for all builders.

PCF 1611 – Prescriptive Path: DHW equipment credits

The points available for a storage-type water heater in Table 9.36.6.10 are substantial, and the UEF listed are easily achieved by most electric storage-type water heaters. It appears that the performance targets may be intended for a combustion appliance baseline. If so, Efficiency Canada suggests indicating that water heating credits are not available for electric water heaters except for heat pump water heaters.

PCF 1611 – Prescriptive path Energy Conservation Points for Building Size

We support this proposed change as is with comment(s).

Section 9.36.6.11 (2) allocates 10 points for building a home less than 230 m2. This is a substantial number of points that incents energy conservation and good design. However, given that Canadian homes are commonly built to sizes below this threshold it may be more effective to reduce the size threshold and/or points available so as to provide further incentives to build right-sized homes and reverse the trend of increasing detached, semi-detached, townhouse and row-house footprints.

Statistics Canada.  Table  46-10-0028-01   Living area and assessment value per square foot of residential properties by property type and period of construction, provinces of Nova Scotia, Ontario and British Columbia

Proposed Change 1596

Proposed Change 1596 is related to the standards and performance requirements for HVAC equipment in Subsection 9.36.3. This change will align Subsection 9.36.3. with current and anticipated standards for the performance of HVAC equipment that can be expected to increase the performance of mechanical equipment.

Further energy efficiency gains in the NBC could be made in space conditioning through the introduction of minimum standards for Smart Home Energy Management Systems such as Smart Thermostats. This area is not currently addressed but these measures have proven to be effective in reducing energy use in homes by at least 8.8%.[1]

Efficiency Canada suggest adding the regulating of smart thermostats into the National Building Code Subsection 9.36.3 to ensure the benefits of smart home technology, particularly time of use smart scheduling and the ability to track energy usage, are available to residents of multi-unit residential building suites, particularly low-income residents. 

1. Natural Resources Canada, “Connected or “smart” thermostats,” https://www.nrcan.gc.ca/energy-efficiency/energy-efficiency-products/product-information/heating-equipment-residential-us/connected-or-smart-thermostats/15781

 

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