Energy Calculations & Modeling Services

Energy compliance and performance analysis aligned with state-specific codes, architectural intent, and project realities

Energy Analysis that Supports Decisions and Code Approval

Energy requirements influence façade design, glazing ratios, system selection, and permitting outcomes. When energy analysis is treated as a late-stage checkbox, it often results in rushed revisions, failed compliance paths, or design compromises that frustrate both architects and owners.
National MEP Engineers provides energy calculation and modeling services that support projects from early design exploration through final permit submission. Our work helps architectural teams understand how design choices affect compliance, energy performance, and long-term operational outcomes, while meeting state and local energy code requirements across the USA.

Energy Compliance Planning Across Codes and Jurisdictions

Energy compliance is not uniform across states. Requirements vary by climate zone, adopted code version, and local amendments. Our team evaluates the applicable energy code at the outset of each project to establish a clear compliance strategy before design decisions are locked. We support projects governed by major US energy standards, including:
  • IECC (International Energy Conservation Code)
  • ASHRAE 90.1
  • California Title 24
  • Florida Building Energy Code
  • State and local amendments adopted by AHJs
We help architects reconcile the energy path early, avoiding redesigns triggered by failed prescriptive, trade-off, or performance-based compliance checks.

Energy Modeling at Every Step of Design Integration

Energy modeling plays different roles at different stages of the design process. During the preliminary phases, it serves as a decision-support tool. Later, it becomes a compliance and documentation requirement. During schematic and design development phases, we use energy models to evaluate envelope performance, glazing strategies, orientation impacts, and system options. This allows architects to compare alternatives, such as façade treatments or HVAC concepts, before committing to costly changes. As projects progress into construction documents, the focus shifts to validated compliance models. We refine inputs, match assumptions with final drawings, and prepare the documentation required for plan review and permit approval.

Modeling Tools for Translating Design Into Measurable Performance

Reliable energy modeling depends on accurate inputs and close coordination across architectural and MEP decisions. We develop models that reflect the designs as they evolve, rather than relying on generic assumptions that fail during review. We create models using industry-standard platforms, including eQuest, EnergyPlus, EnergyPro (for Title 24), and COMcheck, aligning architectural drawings, electrical layouts, and mechanical system data to generate defensible energy calculations.

We use compliance platforms to analyze:
  • Envelope assemblies and thermal performance.
  • Lighting power densities and control strategies.
  • HVAC system efficiency and zoning.
  • Climate-specific energy demand and consumption patterns.
This approach ensures that the energy analysis remains consistent with the design intent while satisfying the calculation methodologies required by the governing code.

Energy Calculation Standards We Master Across the USA

Title 24 is one of the most prescriptive and closely reviewed energy codes in the US, with strict requirements that often influence façade design, system selection, and project timelines. We support California projects by developing Title 24 energy calculations that coordinate with the selected compliance pathway, performance, prescriptive, or exception-based, while coordinating closely with architectural and MEP decisions. Our experience with enforcement nuances helps reduce resubmittals and streamline plan review.
American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard 90.1 is widely used for commercial projects and often serves as the compliance reference when jurisdictions adopt performance-based energy paths. Our ASHRAE 90.1 modeling focuses on establishing accurate baselines, validating energy cost budgets, and demonstrating compliance through performance rating methods. We reflect envelope, lighting, and system assumptions with the design intent to avoid conflicts during permitting and third-party review.
The International Energy Conservation Code serves as the foundation of energy regulation in many states, with variations across adopted editions and local amendments. We initially interpret the applicable IECC version for the project to determine whether prescriptive, trade-off, or performance paths are most suitable. This approach helps architects maintain design flexibility while meeting compliance requirements across different climate zones.
Many jurisdictions implement national energy standards with local amendments that affect modeling assumptions and compliance paths. We consider region-specific requirements, such as Washington State Energy Code efficiency thresholds and Florida Building Code provisions, as well as modifications in cities like Chicago and Seattle. By identifying these amendments proactively in a project, we align energy calculations with AHJ expectations, reducing resubmittals and late-stage design revisions.

Energy Calculation and Modeling Deliverables

Our energy services are tailored to the project scope, jurisdiction, and design phase. Typical deliverables include:
Deliverables may vary based on project type, location, and AHJ requirements.

Why Partner with Us for Energy Analysis

Energy analysis often sits at the intersection of architecture, MEP design, and regulatory review. Our role is to keep that intersection clear and manageable.

Architectural teams work with us because we provide:
Our goal is not just to pass compliance, but to help architects maintain control of the design while efficiently meeting energy regulations.

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Do you have questions or need expert advice? Contact us now, and let our team assist you with your MEP engineering needs!













    FAQs

    Once a compliance path is selected and submitted, changes to glazing ratios, envelope assemblies, HVAC system types, or lighting power densities can trigger recalculation or even a full compliance reset. We help teams understand which early decisions are "locked" versus which remain adjustable without jeopardizing approvals.
    Most energy review delays occur when modeled assumptions no longer align with the issued drawings. We continuously reconcile envelope assemblies, system efficiencies, and lighting layouts against evolving CDs so the compliance documentation mirrors the actual design set reviewed by the AHJ.
    Common issues include mismatched envelope assemblies, undocumented system efficiencies, incorrect baseline assumptions, and inconsistencies between architectural schedules and energy reports. Our models are structured to anticipate these review points and reduce the need for clarification cycles.
    State and local amendments frequently override baseline IECC or ASHRAE provisions, especially around envelope performance, lighting controls, and mechanical efficiencies. We account for these jurisdiction-specific requirements early so projects are not forced into late-stage design compromises.
    When post-submission changes affect energy performance, we assess the impact immediately, revise calculations where required, and prepare a clear justification for AHJ review. This avoids withdrawal-and-resubmission scenarios that delay approvals.