Codes that regulate alterations to existing buildings (AEB), or retrofit codes, present an opportunity to improve energy efficiency each time an existing building undergoes alterations or renovations. These codes are typically part of a federal or provincial building code.

Appliance and equipment energy performance improvements, led either by regulation or industry, are critical energy efficiency drivers. Though the federal government regulates energy efficiency standards, testing standards and labelling requirements for energy-using products through Energy Efficiency Regulations, provinces / territories can introduce more stringent standards, or standards on products not covered by federal regulations.

Building energy codes only save energy if builders comply with them and building officials enforce them. Creating a robust policy framework for code compliance can also help build capacity for more stringent energy codes in the future.

Building codes set minimum standards for new construction, including energy efficiency requirements. Section 9.36 of the National Building Code (NBC) establishes energy efficiency performance requirements for houses and small buildings. The National Energy Code for Buildings (NECB) prescribes minimum performance levels for all types of buildings, and is the standard for commercial, institutional, and high-rise residential buildings (Part 3 of the National Building Code).

A whole-building performance standard is a requirement for existing buildings (or buildings of a certain class or subtype, e.g., rental properties) to meet a specified energy efficiency and/or carbon emissions performance target.

Provinces can participate in the development and harmonization of federal energy efficiency standards. One example is the Canadian Standards Association Steering Committee on the Performance of Energy Efficiency and Renewables (CSA-SCOPEER) that develops standardized testing protocols to measure the energy performance of equipment devices and systems. Another is the Regulatory Reconciliation and Cooperation Table's (RCT) Steering Committee on Energy Efficiency (SCEE) for household appliances composed of federal, provincial and territorial energy efficiency officials.

Evaluating the energy-use performance of a building is a crucial first step toward building performance benchmarking and standards. Public disclosure of energy-use performance can help to integrate the value of energy efficiency into real estate, financial, and/or lending and insurance markets

Local governments, often the ‘authorities having jurisdiction’ over building code enforcement, can be granted the flexibility by the province/territory to enforce a building code with higher performance standards than the provincial base code in their jurisdiction. Maintaining harmonization of codes across the province is made possible when provincial governments include the tiered framework when adopting the national building codes.

Space heating is the largest contributor to both residential and commercial energy use in Canada. Water heating accounts for an additional 18 per cent of the energy used in Canadian homes and 6 per cent in businesses and institutions. Appliance and equipment standards, and low carbon regulations, that set requirements for efficient and/or low-carbon space or water heating in buildings can dramatically improve a building's energy efficiency and reduce operating costs.