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The data presented here is derived from whole-building energy models of typical (“archetype”) buildings in British Columbia, Canada for the following 3 types: multi-unit-residential building (MURB), row-house or townhouse, and medium single-family dwelling (MSFD). As such, Pathfinder is intended to be used as an educational tool only and does not represent any particular building or design.
Find out more through the tabs on the left, or watch the video tutorial.
Three building types are currently included in Pathfinder. They are described below and other values not described here are modelled as per the BC Energy Step Code. The output metrics relate to the City of Vancouver’s Zero Emissions Building Plan and the BC Energy Step Code. More detailed information on the archetypes is available in the BC Energy Step Code Metrics Report.
The MURB archetype building is cooled by typical in-window air conditioners. Domestic hot water is heated by a condensing gas boiler and low-flow fixtures are assumed (a flow savings of 20% over code). Ventilation rates default to the minimum required by code and the air is provided independently to suites and corridors, the latter of which is provided using a 90% efficient natural-gas fired make-up air unit.
The MSFD archetype building is a two-storey house on a basement, it's not cooled and ventilation rates default to the minimum required by code. The window-to-wall ratio is 0.13 and the floor area is 237 m2.
The row-house archetype building is a three-storey row-house on grade, it's not cooled and ventilation rates default to the minimum required by code. The window-to-wall ratio is 0.2 and the floor area is 1,007 m2.
Airtightness describes how much uncontrolled and undesired outdoor air is entering a building through cracks, window frames and other unintentional openings. The amount of infiltration will vary depending on the type of construction, windows and degree of attention paid to air sealing.
The values shown here are in airchanges per hour (ACH). A common value would be 3.5 ACH and a PassiveHouse level would approach 0.6 ACH.
The insulating value of a wall is indicated by its R value. The higher the R value the lower the heat loss through the surface. The units used in the Building Pathfinder are (hr·ft2·°F)/Btu, the metric equivalent is K·m2/W. To convert between R and RSI, use 1 K·m2/W = 5.678 (hr·ft2·°F)/Btu. A wall with R-value of 15 has an RSI of approximately 2.64.
The value entered here should be the overall system value, not simply the nominal value of the insulation layer in the wall assembly. The system value accounts for thermal bridging effects from studs, shelf-angles, window-to-wall transitions, etc. For detailed information about how to account for thermal bridging see the City of Vancouver Energy Modelling Guidelines and the Building Envelope Thermal Bridging Guide.
The insulating value of a slab is indicated by its R value. The higher the R value the lower the heat loss through the surface. The units used in the Building Pathfinder are (hr·ft2·°F)/Btu, the metric equivalent is K·m2/W. To convert between R and RSI, use 1 K·m2/W = 5.678 (hr·ft2·°F)/Btu. A slab with R-value of 15 has an RSI of approximately 2.64.
The value entered here should be the overall system value, not simply the nominal value of the insulation layer in the slab assembly. The system value accounts for thermal bridging effects from studs, shelf-angles, window-to-wall transitions, etc. For detailed information about how to account for thermal bridging see the City of Vancouver Energy Modelling Guidelines and the Building Envelope Thermal Bridging Guide.
The insulating value of a roof is indicated by its R value. The higher the R value the lower the heat loss through the surface. The units used in the Building Pathfinder are (hr·ft2·°F)/Btu, the metric equivalent is K·m2/W. To convert between R and RSI, use 1 K·m2/W = 5.678 (hr·ft2·°F)/Btu. A roof with R-value of 15 has an RSI of approximately 2.64.
The value entered here should be the overall system value, not simply the nominal value of the insulation layer in the roof assembly. The system value accounts for thermal bridging effects from studs, shelf-angles, window-to-wall transitions, etc. For detailed information about how to account for thermal bridging see the City of Vancouver Energy Modelling Guidelines and the Building Envelope Thermal Bridging Guide.
The overall system U-value should be used here, not simply the center-of-glass U-value. The system value includes the effects of the framing and the edge-of-glass effects.
Typical values are as follows:
| Double-glazed, Fixed, 1/2 inch Argon Space, Thermal Break | System U-value (BTU/(hr ft2 °F)) |
|---|---|
| Aluminum frame, no low-e coating | 0.53 |
| Aluminum frame, with low-e coating | 0.38 |
| Vinyl frame, no low-e coating | 0.47 |
| Vinyl frame, with low-e coating | 0.32 |
| Tripe-glazed, Fixed, 1/2 inch Argon Space, Thermal Break | System U-value (BTU/(hr ft2 °F)) |
| Aluminum frame, no low-e coating | 0.40 |
| Aluminum frame, with low-e coating | 0.27 |
| Vinyl frame, no low-e coating | 0.34 |
| Vinyl frame, with low-e coating | 0.21 |
The domestic water heating system types examined include traditional electric, gas-fire instant heater and heat-pump-based heating.
Energy can be recovered from domestic water as it drains. The efficiency can vary by technology and installation, but a 42% efficiency is shown here.
The space heating system and fuel source describes how the building's space heating loads are satisfied. The baseboard option is electric baseboards, the gas furnace is an air-based gas-fired heating system, and the CCASHP is an air-source heat pump.
Heat/Energy recovery ventilators (HRV/ERV) use the warm air being exhausted from a building to temper the incoming outdoor air. This reduces the amount of heating required in the building and so is an important factor in reducing overall energy use. The effectiveness value of an HRV/ERV corresponds to how much the device can preheat incoming air relative to an idealized condition where the preheated air temperature would be equal to the exhaust air temperature. The effectiveness value can also be a rough approximation of the reduction in ventilation air heating requirements (i.e. an HRV/ERV with an effectiveness of 50% will provide about 50% of a reduction in ventilation air heating).
Typical values for a small, residential HRV would be roughly 60-70%. Larger units and/or high-quality, high-end units can have an effectiveness of upwards of >85%.
Thermal Energy Demand Intensity (TEDI) is in units of equivalent kWh/m2. This metric represents the annual heating load of the building, which is generally reflective of the performance of the envelope and quantity and performance of the ventilation systems, on a per unit floor area basis. It does not account for the efficiency or type of the heating system. In this particular example, it is the output of all of the electric baseboards and heating output of the gas-fired make-up air unit for the corridors. It specifically excludes domestic hot water.
Mechanical Energy Use Intensity (MEUI) is in units of equivalent kWh/m2. This metric represents the annual energy use for mechanical equipment in the building, such as fans, pumps, boilers, etc, on a per unit floor area basis.
Peak Thermal Load (PTL) is the highest rate of heating required during the year on a per unit floor area basis. The units used here are kW/m2.
The value shown here is the percent increase in cost of a building constructed to include the features selected, compared to the reference archetype building as described in the BC Energy Step Code Metrics Report.