BCBC Part 9 Ceiling Thermal Resistance Calculator
Calculate the effective thermal resistance (R-value / RSI) of common ceiling assemblies, including vented spaces. Select your ceiling components and insulation, and review the results in the table below.
*Nominal dimensions for dimensional lumber, depth for I-joists.
*This is the nominal RSI of insulation within the joist/truss cavity.
*o.c. = on center (spacing)
Selecting a preset will automatically configure the options above and below.
*HDD = Heating Degree Days. Refer to BCBC for your location.
6. Ceiling Components
Select the material for each layer. The R-value (Imperial) and RSI (Metric) will be automatically populated.
| Layer Description | Material Selection | R-value (Imperial) | RSI (Metric) |
|---|---|---|---|
| Layer 1: Inside Air Film (Upward) | -- | -- | |
| Layer 2: Ceiling Finish (e.g., Gypsum Board) | -- | -- | |
| Calculated Remaining Air Gap (Physical in Cavity) | -- mm | -- * | -- * |
| Framed Cavity (based on selections above) | N/A | -- | -- |
| Layer 3: Vented Air Space (e.g., from strapping) | -- | -- | |
| Layer 4: Roof Sheathing (e.g., OSB, Plywood) | -- | -- | |
| Layer 5: Roofing Material (e.g., Asphalt Shingles) | -- | -- | |
| Layer 6: Outside Air Film (Roof, Upward) | -- | -- |
Total Results:
Total Effective R-Value (Imperial): -- $ft^2 \cdot \text{hr} \cdot \text{°F/BTU}$
Total Effective RSI (Metric): -- $m^2 \cdot K/W$
Disclaimer: This calculator provides an estimation based on common values and representative tables.
For BCBC Part 9 compliance, always refer to the official BC Building Code, specific product data,
and consult with a qualified building professional or energy advisor.
Thermal bridging factors are complex and simplified here.
* Note on "Calculated Remaining Air Gap": The RSI/R-value for this line item is displayed for informational purposes, indicating the theoretical thermal resistance of the physical air space remaining *within the main framed cavity*. However, this value is NOT added to the "Total Effective R-Value" because the "Framed Cavity" R-value (from BCBC tables) already accounts for the combined thermal performance of the framing, insulation, and any inherent air films/gaps within the cavity.
7. Export Results Table
BCBC Part 9 Foundation Wall Thermal Resistance Calculator
Calculate the effective thermal resistance (R-value / RSI) of common concrete foundation wall assemblies. Select your wall components and insulation, and review the results in the table below.
*HDD = Heating Degree Days. Refer to BCBC for your location.
Selecting a preset will automatically configure the layers below.
3. Foundation Wall Components
Select the material for each layer, from interior to exterior. The R-value (Imperial) and RSI (Metric) will be automatically populated.
| Layer Description | Material Selection | R-value (Imperial) | RSI (Metric) |
|---|---|---|---|
| Layer 1: Inside Air Film (Horizontal) | -- | -- | |
| Layer 2: Interior Wall Assembly (Framed or ICF) | -- | -- | |
| Calculated Remaining Air Gap (Within Wood Framed Walls Only) | -- mm | -- * | -- * |
| Layer 3: Interior Applied Continuous Insulation (CI) (Optional) | -- | -- | |
| Layer 4: Concrete Wall (e.g., 200mm / 8") | -- | -- | |
| Layer 5: Exterior Continuous Insulation (CI) | -- | -- | |
| Layer 6: Damp-proofing / Drainage Membrane | -- | -- | |
| Layer 7: Exterior Contact (Air Film or Soil) | -- | -- |
Total Results:
Total Effective R-Value (Imperial): -- $ft^2 \cdot \text{hr} \cdot \text{°F/BTU}$
Total Effective RSI (Metric): -- $m^2 \cdot K/W$
Disclaimer: This calculator provides an estimation based on common values and representative tables for individual layers.
For BCBC Part 9 compliance of foundation walls, typically an **effective R-value for the entire assembly** (concrete, insulation, and soil interaction) is considered. Soil thermal properties are complex and can vary significantly with moisture content and composition.
This tool simplifies these factors. A complete foundation design also requires addressing **structural loads, proper concrete mix design, appropriate rebar placement, and robust moisture management systems (damp-proofing, waterproofing, and drainage)**, which are not detailed in this thermal resistance calculator.
Always refer to the official BC Building Code, specific product data,
and consult with a qualified building professional or energy advisor for accurate compliance and a comprehensive design.
* Note on "Calculated Remaining Air Gap": The RSI/R-value for this line item is displayed for informational purposes, indicating the theoretical thermal resistance of the physical air space remaining *within the interior framed cavity*. However, this value is NOT added to the "Total Effective R-Value" because the "Interior Framed Wall" R-value (from tables) already accounts for the combined thermal performance of the framing, insulation, and any inherent air films/gaps within that part of the assembly.