Building Energy Modeling and Optimization


Simplify Energy Code Compliance

Energy modeling can be used to demonstrate building efficiency, as an alternative to meeting a long list of design requirements.


Optimize Your Building Design

Simulate energy consumption and operating costs for multiple building designs, and choose the highest-ROI option for construction.


Qualify for Building Certifications

Improve the efficiency of your buildings with energy modeling, and meet ENERGY STAR and LEED Certification requirements.

EOS Labs

Every consultant on our team has at least 10 years of experience in design, construction, maintenance, sustainability, or facilities management.

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Buildings Served

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energy savings

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  • Credentials
  • Professional Engineers - PE
  • Certified Energy Manager – CEM
  • PhD
  • ISO 9001 Auditor
  • RFMP and more
Energy efficiency measures for buildings are often compared based on “rules of thumb” or typical percentage savings specified by vendors. This approach is simple but very inaccurate, and energy savings tend to be over- or underestimated. Better investment decisions are possible if you analyze energy upgrades with methods that offer higher accuracy and reliability.
Building energy modeling provides an accurate simulation of energy usage by considering factors like construction materials, architecture and the local weather. Energy modeling also analyzes the interactions between different building systems, which are not considered when energy efficiency measures are analyzed in isolation. Energy modeling can also help you qualify for financial incentives and building certifications such as LEED and ENERGY STAR.
EOS Labs is an ENERGY STAR Service Partner, and we can help you improve energy performance across your building portfolio. Using energy modeling software and our expertise across multiple projects, we can help you reduce the operating costs of both existing buildings and new constructions.
Energy modeling is a versatile tool with many applications, and it can be used across multiple building types and climate zones.

The applications of energy modeling include:
  • Compliance with local energy codes and climate laws.
  • Qualifying for financial incentives such as rebates and tax credits.
  • Reducing project costs, by calculating the optimal capacity of HVAC equipment and other building systems.
  • Comparing different combinations of building energy upgrades, and finding the option with the highest return on investment.
  • Meeting the energy performance requirements of LEED and other green building certifications.
  • Achieving the ENERGY STAR Certification for Buildings.
Local energy codes often give you the option of meeting a list of prescriptive design requirements, or demonstrating energy performance with approved modeling software. If you decide to follow prescriptive requirements in a building project, they can limit your design options while increasing overall costs. On the other hand, energy modeling gives you flexibility: as long as your building reaches the minimum performance level established by energy codes, there is no need to meet a list of specific requirements.
Energy modeling is also useful in jurisdictions with building emission limits, since you can use it to demonstrate compliance. You can calculate your consumption of different energy sources accurately (electricity, natural gas, heating oil, etc.), and then determine your total emissions based on the carbon footprint of each source. Building energy modeling is also used by government agencies when developing energy codes and incentive programs, and when making policy decisions.

How Does Energy Modeling Work?

Under the traditional design approach, building systems such as HVAC and lighting are analyzed independently. With energy modeling, the entire building is analyzed as a single system with interacting components, while also considering operating schedules and the local weather. This results in a more accurate calculation of how buildings use energy throughout the year.

Energy modeling software uses a large number of inputs to predict the energy performance of a building.

There are many software packages in the market, with different interfaces and features, but they generally use the following inputs:

Geometry, construction materials, window placement, building orientation, insulation levels, etc.

HVAC equipment, ductwork, piping, lighting fixtures, motors, water heaters, refrigeration equipment, onsite generation systems, energy storage systems, etc.

Occupancy rates, schedules, local electricity and gas prices, HVAC zoning requirements, local weather, etc.

Using this information, energy modeling software can predict how a building will consume energy throughout the year. One of the main advantages of energy modeling is being able to analyze the interactions between building systems and how they influence energy consumption.

As a quick example, assume you upgrade from fluorescent to LED fixtures, reducing the power consumption of the lighting system by 50%.

  • If the lighting system is analyzed in isolation, the resulting energy savings are only calculated based on the direct reduction of electricity consumption.
  • However, high-efficiency lighting also emits less heat, reducing the workload on air conditioning systems during summer.
  • High-efficiency lighting has the opposite effect on space heating systems during winter. Since the heat emission of lighting fixtures is reduced, heating systems have a slightly higher workload after the upgrade.

If a major LED retrofit reduces the heat emissions of a building’s lighting system by 100 kW, the air conditioning workload is reduced by over 341,200 BTU/h (1 kW = 3.412 BTU/h). However, the space heating system must now provide 341,200 BTU/h that were previously delivered by the less-efficient light fixtures.

  • Normally, the lighting and air conditioning savings achieved by LED fixtures are much higher than the increase in heating load.
  • This analysis is very complex when using manual calculations, but energy modeling software can easily simulate interactions between building systems.

This is just an example of how the interaction between building systems can influence energy performance. These behaviors are not normally considered when using traditional design methods or simplified calculations. Energy modeling provides a more accurate picture of how your building uses energy, and how design decisions affect its consumption.

Energy modeling can be used to optimize the capacity of building equipment in new construction projects, in addition to improving energy performance. Traditional design methods often result in oversized equipment, which has a higher price and increased O&M costs over time. On the other hand, with energy modeling you can size equipment based on the unique operating conditions of each building:

  • You can simulate the performance of different equipment options and the interactions between building systems during the design stage.
  • This is especially useful when designing HVAC systems, which account for over 50% of energy consumption in many residential and commercial buildings.

If you’re seeking LEED certification for a new building, energy modeling is a very helpful tool. Under the LEED Building Design + Construction (BD+C) certification, which applies for new constructions, you can earn up to 35 points for energy performance.

Considering that you need 40 points for a basic LEED Certification, it makes sense to focus on energy efficiency during the design stage. If you have already earned many LEED points in other performance areas like water conservation and indoor air quality, energy modeling can boost your score and help you reach the higher certification levels (LEED Silver, Gold or Platinum).

Energy modeling can also be used to improve the energy performance of existing buildings. This is very helpful in cities that are currently introducing emissions limits for existing properties: you can test the performance of building retrofit projects before spending capital, making sure they achieve the required emissions reductions.

If you’re planning a major renovation, you have an excellent opportunity to use energy modeling.

  • Energy upgrades that require considerable modifications can be very difficult to implement when a building is operating normally.
  • However, a major renovation gives you the opportunity to implement energy efficiency measures that would be very disruptive under normal conditions.
  • You can use energy modeling to compare different energy upgrades, and choose a combination that minimizes your electricity and gas bills.

Energy modeling is also a powerful tool if you’re seeking a LEED or ENERGY STAR Certification in an existing building. Energy efficiency is one of the main performance areas considered in the LEED rating system, and your building must be among the top 25% most efficient properties of its type to qualify for the ENERGY STAR Certification. Energy modeling can help your building qualify for both certifications simultaneously, and you can rely on EOS Labs’ experience as an ENERGY STAR Service Partner.