1. Northwest Energy Code Compliance with Mass Wall Assemblies

2. Mass Wall Benefits Providing Effective Thermal Storage
Dampening heating and cooling loads
Shifting peak loads to off-peak hours

3. Code Compliance Paths Prescriptive Path Component Performance
Systems Analysis
• Prescriptive path tables contain maximum U-value (minimum R-value) requirements for all building envelope components.
• Component performance allows trade-offs between individual component requirement while not exceeding the total energy use when complying prescriptively.
• Washington allows trade-off calculations and ASHRAE ENVSTD software. Oregon STA (simplified trade-off approach) uses software developed by ODOE.
• Systems analysis is used for more complex buildings. Analyzes lighting, HVAC equipment and building envelope components. Called “whole building” approach in Oregon.
Updated

4. Washington State Energy Code
Alternative Prescriptive Path Wall Requirements
Wall Type
Entire State
CMU
U = 0.104*
* Partially grouted wall with integral insulation complies for certain building uses.
• Heat capacity (HC) > 9 equates to a wall weight of 45 psf (any partial grouted 8” CMU wall).
• Zone 1 includes portions of Eastern WA along with Western WA. OR
Wall Type
Entire State
CMU
R = 9.5 continuous insulation*
* Partially grouted wall with integral insulation complies for certain building uses.
Updated

5. R-11.4 continuous insulation
Oregon Energy Code
Alternative Prescriptive Path Wall Requirements
Glazing area maximum = 30%
Wall Type
Max. U-Factor
CMU
U = 0.15*
* Partially grouted wall with integral insulation complies for specific building uses.
• Heat capacity (HC) > 9 equates to a wall weight of 45 psf (any partial grouted 8” CMU wall).
• Zone 1 includes portions of Eastern WA along with Western WA. OR
Wall Type
R-Value
CMU
R-11.4 continuous insulation
Updated

6. Code Compliance
Integral insulated, partial-grouted concrete masonry walls can comply with northwest energy codes.
• This wall complies prescriptively with the Northwest codes in most instances without interior insulation. (Up to 32” oc x 48” oc grouting, approx. 40% in Washington, and 50% grout in Oregon.))
Updated

7. Integral Insulation Methods

8. Integral Insulation Methods
Injected Foam Insulation Continuous Non-Grouted Cells
Patch Injection Ports W/ Mortar to Match Existing

9. Integral Insulation Methods

10. Mass Wall Insulation Options
Z channel or
other furring
Loose fill or
insulation inserts
Stucco or
other finish
Insulation
Gypsum
Board
Insulation
INTERIOR
INTEGRAL
EXTERIOR

11. Mass Wall Insulation Options
• Veneer/cavity walls can be constructed with flashing within the masonry wall.
Updated

12. Optimize Energy Performance
Use comprehensive, whole-building energy analysis program with hour-by-hour simulation
These programs can accurately model concrete masonry’s thermal mass and predict the associated energy savings
Constant Inside
Temperature
Outside
Cycle
Time
(hrs) 24
Heat Flow

13. Northwest Energy Code Compliance with Mass Wall Assemblies
Integral insulated, partial-grouted masonry walls do comply with northwest energy codes. Architectural concrete masonry units can be exposed on both sides in many building designs providing attractive appearance, fire-resistance, and durable surfaces.

14. Northwest Energy Code Compliance with Mass Wall Assemblies
CMU walls can meet Oregon & Washington prescriptive codes through compliance with average U-Factors OR the integral insulated mass wall exception. The use of continuous insulation is an additional option, not a requirement.