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Energy efficiency home evaluation glossary

Whether you're a homeowner looking to boost your home's energy efficiency or simply curious about energy-saving strategies, this glossary will guide you through the terminology and make your energy-saving journey more informed and engaging.

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The U-Factor, or thermal transmittance, measures the rate of heat transfer through a building component. It is calculated as the inverse of the R-value (U = 1/R). It considers the conductivity of materials, surface resistances, and thicknesses.

Low U-Factor: Indicates better insulation properties, meaning less heat transfer, improved energy efficiency, and better indoor temperature control.

High U-Factor: Signifies poor insulation, leading to higher heat loss or gain, increased energy consumption, and reduced comfort levels inside the building. 

This measure is crucial in determining the energy efficiency of windows, doors, and other building elements.


1. EnerGuide Rating: A numerical value representing the energy performance of your home, indicating the net amount of energy consumed annually.

2. EnerGuide Label: A label provided after an evaluation that includes the EnerGuide rating and other energy performance details of your home.

3. Homeowner Information Sheet: A document summarizing the results of your EnerGuide home evaluation, including energy consumption and recommendations.

4. Renovation Upgrade Report: A detailed report suggesting specific improvements and retrofits to enhance your home’s energy efficiency.

5. Energy Performance: The measure of how effectively a home uses energy, typically for heating, cooling, and other functions.

6. Net Energy Consumption: The total amount of energy a home uses over a year, minus any energy produced on-site (e.g., solar panels).

7. Retrofit Journey: The process of making improvements to an existing home to increase its energy efficiency.

8. Evaluation Results: The findings from an EnerGuide home evaluation, including energy ratings, labels, and recommendations for upgrades.

9. Interpreting Results: Understanding the information provided by the EnerGuide evaluation to make informed decisions about home energy improvements.

10. Energy Consumption Estimate: An approximation of the amount of energy a home will use annually, provided by the EnerGuide rating.

11. Gigajoule (GJ): A unit of energy measurement. One gigajoule is equivalent to one billion joules. Used to quantify annual energy consumption in homes.

12. Rating Scale: A scale used to compare the energy performance of homes, where a lower number indicates better performance.

13. Zero Energy Home: A home that produces as much energy as it consumes, resulting in an EnerGuide rating of zero gigajoules per year.

14. Typical New House: A reference point for EnerGuide ratings, representing a version of your home built to typical new construction standards for energy performance.

15. Building Envelope: The physical barrier between the interior and exterior of a home, including walls, floors, roofs, windows, and doors, which impacts energy efficiency.

16. Mechanical Components: The systems within a home that contribute to energy consumption, such as heating, cooling, and ventilation systems.

17. Annual Energy Consumption: The total amount of energy used by a home in one year, expressed in gigajoules (GJ/year).

18. Energy Performance Indicator: A visual or numerical representation of a home’s energy efficiency, often shown on the EnerGuide label and homeowner information sheet.

19.Passive Solar Gain: The use of the sun's energy for heating spaces within a home through design features like windows, walls, and floors that collect, store, and distribute solar energy.

20.Rated Energy Intensity: The amount of energy used per unit area of a building, typically measured in gigajoules per square meter per year (GJ/m²/year).

21.Insulation Values: Metrics that indicate the effectiveness of insulation materials in resisting heat flow, often expressed as R-values or RSI values.

22.RSI Value: The metric for thermal resistance in the International System of Units (SI), representing the effectiveness of insulation materials.

23.Greenhouse Gas Emissions: The release of gases (e.g., carbon dioxide, methane) into the atmosphere that contribute to the greenhouse effect and climate change, often considered in energy performance assessments.

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