Building officials, particularly those in resource-constrained or rural jurisdictions, face labor-intensive, error-prone, and costly manual reviews of design documents as projects increase in size and complexity. The growing adoption of Building Information Modeling (BIM) and Large Language Models (LLMs) presents opportunities for automated code review (ACR) solutions. This study introduces a novel agent-driven framework that integrates BIM-based data extraction with automated verification using both retrieval-augmented generation (RAG) and Model Context Protocol (MCP) agent pipelines. The framework employs LLM-enabled agents to extract geometry, schedules, and system attributes from heterogeneous file types, which are then processed for building code checking through two complementary mechanisms: (1) direct API calls to the US Department of Energy COMcheck engine, providing deterministic and audit-ready outputs, and (2) RAG-based reasoning over rule provisions, enabling flexible interpretation where coverage is incomplete or ambiguous. The framework was evaluated through case demonstrations, including automated extraction of geometric attributes (such as surface area, tilt, and insulation values), parsing of operational schedules, and validation of lighting allowances under ASHRAE Standard 90.1-2022. Comparative performance tests across multiple LLMs showed that GPT-4o achieved the best balance of efficiency and stability, while smaller models exhibited inconsistencies or failures. Results confirm that MCP agent pipelines outperform RAG reasoning pipelines in rigor and reliability. This work advances ACR research by demonstrating a scalable, interoperable, and production-ready approach that bridges BIM with authoritative code review tools.

The U.S. Department of Energy (DOE) Building Energy Codes Program (BECP) periodically evaluates state and national impacts associated with energy codes in residential and commercial buildings. Pacific Northwest National Laboratory (PNNL), funded by DOE, assessed the prospective impacts of national model building energy codes from 2010 through 2040. The model codes of interest in this report are the International Energy Conservation Code (IECC) for residential buildings and ASHRAE Standard 90.1 for commercial buildings. This report describes the methodology used for the assessment and presents the impacts in terms of energy savings, consumer cost savings, and reduced CO2 emissions at the state and national levels.

Building energy codes are essential tools for achieving energy efficiency in buildings. However, the full energy savings potential of these codes can only be realized if buildings are constructed in compliance with them. Therefore, evaluating building energy code compliance is crucial in bridging the gap between the energy efficiency requirements set by energy codes and the actualized energy savings achieved. An energy code compliance evaluation serves as a mechanism to assess construction practices, evaluate the effectiveness of code enforcement, identify gaps in compliance, and guide strategies for improvement through training and education. Conducting code compliance evaluation activities involves field studies that require careful design and significant resources. Historically, more emphasis has been placed on developing and adopting building energy codes, while efforts to evaluate compliance have been relatively limited and lacking consistent approaches. The passage of the 2009 American Recovery and Reinvestment Act (ARRA), which mandated that states create plans for achieving 90% compliance within eight years, stimulated the need for an energy code compliance evaluation. As a result, federal, state, and local governments, and utilities have invested in the development of methodologies and tools for code compliance evaluation studies. This paper reviews the code compliance evaluation studies conducted in the United States over the past three decades. It describes and compares the methodologies and metrics used to assess building energy code compliance, summarizes the general elements and steps involved in the evaluation process, and discusses common issues in these studies. Over time, code compliance evaluation methodologies have evolved from isolated development within individual states, regions, and utilities, to widely accepted protocols applicable across different states and local jurisdictions. There has been a transition in compliance metrics, shifting from historical compliance rates to energy-consumption-oriented approaches.

The United States' national model energy standard for commercial buildings is ANSI/ASHRAE/IES Standard 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings . First published in 1975 (and originally referred to as Standard 90), it provides minimum energy efficiency guidelines for designing, constructing, operating and maintaining new construction and renovated buildings. It is updated continuously, with new editions published every three years. When each new edition of the standard is published, energy and cost savings impacts are quantified by Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy (DOE) Building Energy Codes Program 1 by performing building energy simulations of prototype building energy models 2 constructed to the previous and new edition. This ASHRAE Journal article is a detailed review of the simulation results that formed the basis of the report "Energy Savings Analysis: ANSI/ASHRAE/IES Standard 90.1-2019" 3 in support of DOE's Determination,* which details the qualitative and quantitative comparison of Standard 90.1-2019 to Standard 90.1-2016 to determine its energy savings impacts.

For decades, building energy simulation has been used by architects, engineers, and researchers to evaluate the performance of building designs.Heating, ventilation, and air-conditioning systems are one of the main energy end-users in buildings; hence, it is important to reasonably capture the performance of this equipment in simulations at rated (as defined, for instance, in AHRI and ASHRAE Standards (AHRI, 2020a, 2020b; ASHRAE, 2019)), full load, and part load conditions.Copper is a performance curve generator created to enable building energy simulation practitioners to generate simulation-ready performance curves for heating and cooling equipment that not only capture the equipment's typical behavior at part load, but also match a set of design characteristics, including full load and part load efficiencies.

This study evaluates the degradation in envelope efficiency that could potentially result from a performance based energy code allowing unrestricted compliance trade-offs for improved high-efficiency equipment, including heating, ventilation, and air conditioning (HVAC), domestic hot water (DHW) equipment and/or local renewable energy generation (e.g., photovoltaic (PV) panels). The latest edition of the International Energy Conservation Code (IECC) restricts envelope efficiency trade-offs since from an energy, resilience, comfort and moisture standpoint, a robust thermal envelope is critical to make the house system work as intended. The aim of this study is to conduct a simulation-based evaluation to systematically and quantitatively analyze the national energy and cost impact from trade-offs on the recent IECC code edition.