Energy Consultation

BEE has effectively been working for many years to help architects, developers, and owners to improve building envelope performance. BEE recognizes that water, vapor, and air barrier systems reflected in BEE details need to be well coordinated with the energy model for the project. Therefore, we offer energy services that are focused on building envelope performance. Our Energy Team provides insights and solutions regarding the 2018 Washington State Energy Code (WSEC 2018). Following is a short description of various services BEE provides to ensure the successful design of energy-efficient, sustainable, durable, and cost-effective building envelope:

Building Envelope Energy Code Compliance

This service is focused on delivering building envelope energy code compliance in the most cost-effective way while meeting industry best practice. Our energy code experts will assess a project during design development and periodically review during construction as needed to define the most effective code compliance path, material selection, and assembly details. Along with drawing examination and energy forms, we will also provide heating equipment sizing and renewable energy system sizing. 

With the new 2018 Washington State Energy Code (2018 WSEC) compliance on February 1, 2021 here is our summary of the changes:


  • Each space conditioning category shall demonstrate compliance separately.
  • Wood-framed wall Group-R requires insulation in cavity R25 (typically 2X8 framing).
  • Maximum allowed air leakage has to pass 0.25 cfm/ft@75Pa test.
  • C406 - 6 Credits are required. Each occupancy weights each credit differently. Commissioning is required for all credits: 

           10. Enhanced Envelope 15% Improvement:

  •   Groups R-1, B, E, M   --  3.0 credits
  •   Group R-2                  --  6.0 credits  (Full compliance with C406, with one credit)
  •   All others                    --  4.0 credits

         11.  Reduced Air INfiltration 0.17 cfm/ft@75Pa:

  •  Groups R-1, B, E, M    --  1.0 credit
  •  Group R-2                   --  2.0 credits
  •  All others                     --  1.0 credit
  • C411 Solar Readiness is new to WA for all non-residential buildings up to 20 stories.
  • All metal fenestrations, including metal, have to meet U-3.0 (triple glazing for metal) except AW windows. 


  • R406 credit requirements will be doubled.

            Small units (1,500 sq.ft.)                    R406 -- 3.0 credits up from 1.5
            Medium units (1,500-5,000 sq. ft.)   R406 -- 6.0 credits up from 3.5
            Large units (over 5,000 sq. ft.)          R406 -- 7.0 credits up from 4.5
            R-2                                                         R406 -- 4.5 credits up from 2.5

  • R406.2 Carbon emission equalization. Electric resistance heaters are penalized.
  • Efficient Building Envelope. MAX 3 credits: Triple glazed windows U-0.18; Roof R-60; Wood-framed wall R-21 int + R-16ci; Floor R-48; Entire Slab R-20; OR 40% improvement in energy modeling. Passive House.
  • Air Leakage MAX 2 credits:  0.6ACH@50Pa + Heat Recovery Ventilation. Passive House.
  • Mechanical credits are more aggressive.
  • ​R401.3 Certificate. Insulation values, equipment efficiency, appliance information.
  • ​R405 Simulated Performance Alternative (Performance) - compliance pass.
  • ​R407 Certified Passive House - compliance pass


Air Barrier Design

Our highly experienced team of engineers, inspectors, and testers understand the main requirements for a successful air barrier design. In our design, we account for cost impacts, material availability, project specifics, and general contractor experience and knowledge. It is crucial to coordinate the air barrier design with the weatherization barrier, vapor control, thermal boundary, and proper ventilation to avoid potential issues with the building envelope and help prevent sick building syndrome from airtight buildings.

Building Envelope Details

For a full design project, BEE provides on average over a hundred building envelope details. All of them are being closely examined as part of the Energy Code Compliance and Air Barrier Design services. Most of the building assemblies have multiple layers of materials that can change the building envelope performance based on their application methods and layered position in the assembly. Many materials may perform multiple functions required for a properly functioning building envelope assembly if applied wisely.


Total Building Energy Modeling has multiple benefits. First, it helps designers to choose the best system based on projected performance in the specific to project conditions, like building geometry, envelope performance, location, climate, other building systems, working schedules and utility rates, and many other factors. Second, the model provides the total cost-effectiveness of each system in those specific conditions. Energy modeling is used for green building standards like Built Green, LEED and others. Its also required by many municipality rebates and financing programs. eQUEST and REMrate are the most commonly used software for modeling.

The new energy code requires HVAC Total System Performance Ratio (HVAC TSPR) Modeling for most of the new construction with a few exceptions. BEE Consulting has succesfully modeled hundreds of these projects in recent years.  We offer HVAC TSPR Modeling, as well as Total Building Energy Performance Modeling to our MEP and Architect clients. See specific language below:

“HVAC TOTAL SYSTEM PERFORMANCE RATIO (HVAC TSPR). The ratio of the sum of a building’s annual heating and cooling load in thousands of Btus to the sum of annual carbon emissions in pounds from energy consumption of the building HVAC systems. Carbon emissions shall be calculated by multiplying site energy consumption by the carbon emission factors from Table C407.1.” Per WSEC2018

“C403.1.1 HVAC total system performance ratio (HVAC TSPR). For systems serving office, medical office, retail, library and education occupancies and buildings, and the dwelling units and residential common areas within R-2 multifamily buildings, which are subject to the requirements of Section C403.3.5 without exceptions, the HVAC total system performance ratio (HVAC TSPR) of the proposed design HVAC system shall be more than or equal to the HVAC TSPR of the standard reference design as calculated according to Appendix D, Calculation of HVAC Total System Performance Ratio.”  Per WSEC2018.

Underlining indicates text that the city of Seattle has added to the Washington State Energy Code.



Modeling in THERM helps to understand thermal bridging effects in complex assemblies. We use it to identify how much insulation should be applied before it reaches the maximum effective level. It also identifies potential condensation risk areas.


Feasibility studies help identify available energy or Green Building Incentive Programs. Those programs are oriented to help offset the cost of the energy improvements beyond the minimum requirements of the local codes. Most of the projects are qualify for some of the programs with little to no change to typical construction practice.

Built Green, LEED, RESNET, Energy Star

The BEE team of approved energy raters and verifiers will guide a project through Built Green, LEED, RESNET or Energy Star Certification. We will evaluate all energy and sustainability-related aspects of design, conduct site inspections, and complete required testing and verifications to ensure successful certification of your project.

See BEE Consulting on WSU's list of Certified Home Energy Raters (HERS). Click here.