Energy Modeling

Smarter building decisions start with better data

Plan for performance, compliance, & incentives

RunBrook provides building energy modeling services to help project teams evaluate energy performance, compare design options, support code compliance, and pursue green building certifications, tax credits, and utility incentives.

Whether you are designing a new building, improving an existing property, or evaluating energy-saving strategies, energy modeling provides the data needed to make informed decisions before construction begins.

Why energy modeling matters


Compare options before you build

Energy modeling gives owners, developers, architects, engineers, and builders a clearer understanding of how a building is expected to perform before major design and construction decisions are finalized.

By comparing different envelope, HVAC, lighting, water heating, control, and renewable energy strategies, project teams can identify which options offer the strongest performance, best value, and most practical path toward compliance or certification.

  • Demonstrate that a building meets applicable energy code requirements through approved performance-based modeling paths.

  • Compare different envelope, HVAC, lighting, and system strategies to identify efficient and cost-effective solutions.

  • Estimate long-term energy use and utility costs before construction or renovation decisions are finalized.

  • Provide modeling documentation for programs such as LEED, NGBS, FGBC, ENERGY STAR, and other above-code standards.

  • Use energy modeling to support tax credits, utility incentives, rebates, or other financial programs where applicable.

  • Evaluate thermal loads and system performance to help support right-sized, efficient HVAC system design.

How building energy modeling works

Building energy modeling, often called whole-building energy modeling, is a software-based simulation used to estimate how a building will use energy. The model evaluates the building’s design, materials, systems, schedules, local weather conditions, and operating assumptions to calculate expected energy performance.

An energy model can help project teams understand how design choices affect heating, cooling, lighting, water heating, ventilation, equipment loads, comfort, operating costs, and overall building efficiency.

For many projects, energy modeling is used to demonstrate code compliance, support green building certification, compare retrofit options, qualify for financial incentives, or guide energy-efficient design decisions.

A building energy model uses physics-based software to simulate how a building is expected to perform. The model includes information about the building’s geometry, construction assemblies, mechanical systems, lighting, water heating, controls, renewable energy systems, and operating schedules.

Modern white residential building with balconies, surrounded by palm trees and greenery, under a bright blue sky.

RunBrook provided energy modeling services for 701 Valencia, an FGBC-certified high-rise project in Coral Gables, Florida.

Once the model inputs are developed, the software combines those assumptions with local weather data to estimate heating and cooling loads, system response, energy consumption, utility costs, and comfort-related performance metrics.

This helps project teams understand not only how much energy a building may use, but why it uses that energy and which design decisions have the greatest impact.

Energy modeling for IECC compliance

Support for evolving energy code requirements

The International Energy Conservation Code, or IECC, is one of the primary model energy codes used across the United States for residential and commercial building energy performance. The IECC is updated on a regular code cycle, with recent editions including the 2021 IECC and the newer 2024 IECC. However, adoption varies by state, city, county, and local jurisdiction. Many areas are still enforcing older versions of the IECC or have adopted local amendments that change how compliance is demonstrated.

Because code adoption is not the same everywhere, it is important to confirm which version of the IECC or local energy code applies before design decisions are finalized. RunBrook can help project teams understand applicable requirements, evaluate compliance options, and prepare the documentation needed for permitting, plan review, or inspection.

Cover of the 2012 International Energy Conservation Code (IECC) with a green background, globe illustration, and ICC logo.

Common uses for energy modeling

Energy modeling can support a wide range of project goals, including:

  • IECC performance path compliance

  • Local energy code documentation

  • State and jurisdiction-specific code review

  • New building design

  • Existing building retrofits

  • Tax credit qualification

  • Utility incentive applications

  • HVAC design support

  • Owner decision-making and budgeting

  • Whole-building performance comparisons

  • Green building certification

    • LEED documentation

    • NGBS certification support

    • ENERGY STAR program support

What goes into the energy model?

Building geometry

  • floor area

  • building orientation

  • window-to-wall ratios

  • roof, wall, & floor layouts

  • space types & zoning

Lighting & plug loads

  • lighting power density

  • occupancy schedules

  • equipment loads

  • controls & sensors

Envelope & materials

  • wall assemblies

  • roof insulation

  • window performance

  • air leakage assumptions

  • thermal mass

  • shading conditions

Water heating & refrigerant

  • domestic hot water systems

  • pumping energy

  • refrigeration systems

  • system controls & efficiencies

HVAC systems

  • equipment type

  • system efficiencies

  • ventilation strategy

  • heating & cooling capacity

  • controls & schedules

  • fan energy

Renewable energy

  • solar PV systems

  • battery storage assumptions

  • renewable generation estimates

  • energy offset calculations

Energy modeling for new construction

Build smarter from the start

For new construction projects, energy modeling helps project teams evaluate performance before major design and cost decisions are finalized. By comparing different building assemblies, HVAC systems, lighting strategies, and control approaches, energy modeling can help identify the most effective path toward code compliance, certification, and long-term operational savings.

This process can also help reduce unnecessary upfront costs by showing where efficiency measures provide the greatest value and where certain design choices may have less impact.

An aerial view of a residential neighborhood with houses, trees, streets, and cars.
Modern Porsche car dealership with a white exterior, large glass windows, and the Porsche logo in red on the front.

RunBrook provided energy modeling services for Porsche Hartford, a commercial project located in Hartford, Connecticut.

Energy modeling for certifications & incentives

Support for above-code programs

Energy modeling is often required or highly beneficial for projects pursuing green building certifications, utility incentives, tax credits, or performance-based compliance paths.

RunBrook can provide modeling support for programs and goals such as:

  • LEED certification

  • NGBS certification

  • ENERGY STAR certification

  • Energy code performance paths

  • Tax credit documentation

  • Utility incentive programs

  • Owner sustainability goals

  • Carbon reduction strategies

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Our process

Clear, collaborative, and data-driven

Step - 1 Review project information

We collect and review drawings, specifications, system information, schedules, and project goals.


Step - 2 Build the energy model

Our team creates a whole-building energy model using project-specific inputs and applicable performance assumptions.


We perform blower door, duct testing, and HERS ratings in alignment with construction schedules.

Step - 3 Analyze design options


Step 4 - Provide results & documentation

We deliver ratings and documentation required for inspections, certifications, and home closings.

Three people sitting at a table with architectural plans and drawings, discussing construction or urban development, with a large window showing a modern residential building complex outside.

Why choose RunBrook?

Building performance expertise beyond the model

RunBrook brings practical building science knowledge to every energy modeling project. Because our team also supports HERS ratings, green certifications, blower door testing, duct leakage testing, HVAC grading, and quality assurance inspections, we understand how modeled assumptions connect to real-world construction and performance.

Project teams choose RunBrook for:

Modern multi-story building with glass windows and a black and orange exterior, surrounded by trees and vehicles on the street.
  • Whole-building energy modeling experience

  • Code compliance and certification support

  • Residential, multifamily, and commercial project expertise

  • Practical building science knowledge

  • HVAC, envelope, and system performance insight

  • Support for LEED, NGBS, ENERGY STAR, and other programs

  • Clear reporting and documentation

  • Collaborative support for architects, engineers, builders, and developers

  • Experience with new construction and retrofit projects

Frequently Asked Questions

  • Energy modeling is most valuable early in the design process, before major decisions about building envelope, HVAC systems, lighting, and materials are finalized.

  • Yes. By comparing design options, energy modeling can help identify cost-effective strategies and avoid unnecessary upgrades that may not provide meaningful performance benefits.

  • Yes. Energy modeling can help evaluate thermal loads and system performance, supporting more efficient and appropriate HVAC design decisions.

  • Typical inputs include architectural drawings, mechanical system information, construction assemblies, lighting details, water heating systems, schedules, occupancy assumptions, and project goals.

  • Yes. Energy modeling can be used to evaluate retrofit strategies, compare energy conservation measures, estimate savings, and support incentive applications.

  • Yes. Energy modeling is often used to support green building certification documentation, including LEED, NGBS, ENERGY STAR, and other above-code programs.

  • Yes. RunBrook can help interpret model results and identify practical strategies to improve energy performance, support compliance, or meet certification goals.

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Prefer to talk first?

Call us at 1-833-RunBrook

(1-833-786-2766)

or email us directly at info@runbrook.com

We’ll get back to you right away!

Discuss Your Next Project

If your project requires energy modeling, certification support, HERS ratings, blower door testing, or other building performance services, RunBrook can help keep the process moving from design through final verification.