ANSI ASHRAE IES Standard 90.2-2018 PDF

Full title and description

ANSI/ASHRAE/IES Standard 90.2-2018 — Energy‑Efficient Design of Low‑Rise Residential Buildings. An American National Standard that establishes minimum whole‑building energy performance, prescriptive and performance compliance paths, and verification requirements for new low‑rise residential buildings and for new portions or systems of existing low‑rise residential buildings.

Abstract

This 2018 edition of Standard 90.2 provides technical requirements and compliance pathways to achieve cost‑effective energy performance for one‑ and two‑family dwellings, multifamily structures three stories or fewer above grade, manufactured (modular/mobile) homes, and associated outbuildings. The standard addresses the building envelope, HVAC and service‑water‑heating systems, lighting and controls, major appliances and service equipment, pools and snow/ice‑melt systems, on‑site power, and verification/installation practices. The 2018 revision emphasizes a performance‑based approach that targets substantially higher efficiency (the committee sought outcomes significantly better than older baselines) and adds guidance on modeling, airtightness verification, and installation practices.

General information

• Status: Historical edition (ANSI/ASHRAE/IES Standard 90.2-2018); later superseded by the 2024 edition.
• Publication date: January 2018 (published as ANSI/ASHRAE/IES Standard 90.2-2018).
• Publisher: American Society of Heating, Refrigerating and Air‑Conditioning Engineers (ASHRAE), co‑sponsored by the Illuminating Engineering Society (IES); ANSI approved.
• ICS / categories: Building engineering / energy efficiency (relevant ICS groups include construction and building technology; thermal insulation and energy efficiency in buildings).
• Edition / version: 2018 edition (ANSI/ASHRAE/IES Standard 90.2-2018).
• Number of pages: Approximately 100–110 pages (official PDF runs roughly 106 pages in typical distributions).

Scope

Standard 90.2-2018 applies to the design, construction, and verification of new low‑rise residential buildings and to new portions or systems of existing low‑rise residential buildings. It covers single‑family homes, multifamily buildings three stories or fewer above grade, manufactured/modular homes, and related accessory structures. The standard sets minimum energy‑efficiency requirements for the building envelope, heating and cooling systems, domestic hot water, lighting, major appliances and service equipment, and certain exterior systems (pools, snow/ice melt). It does not address operation and maintenance procedures or transient housing (hotels, motels, dormitories, nursing homes, jails, barracks) unless explicitly noted.

Key topics and requirements

• Prescriptive envelope requirements (insulation, fenestration U‑factors and SHGC) with climate‑zone tables.
• Performance compliance path using whole‑building energy or energy‑cost modeling.
• Heating, ventilation, and air‑conditioning (HVAC) efficiency requirements and sizing/load guidance.
• Service hot‑water system efficiency and controls.
• Minimum lighting efficacy and control requirements for permanent lighting and specified fixtures.
• Air‑tightness and envelope verification (testing and documentation requirements).
• Requirements and specifications for on‑site power (PV) and integration with building energy models.
• New performance specifications for ground‑source heat pumps and related systems.
• Compliance reporting and software guidance to ensure repeatable, comparable simulation results.
• Normative installation guidance (added normative appendix addressing installation practices for critical thermal resistance components).

Typical use and users

Used by architects, residential mechanical/electrical designers, energy modelers, builders, code officials, plan reviewers, multifamily developers, utility program managers, and standards/codes staff. It is applied for design decisions, energy compliance submittals, energy‑efficiency incentive programs, and as a technical reference for high‑performance residential design and verification.

Related standards

ANSI/ASHRAE/IES Standard 90.2-2018 is part of ASHRAE’s family of energy standards and is closely related to: ASHRAE Standard 90.1 (Energy Standard for Buildings Except Low‑Rise Residential Buildings — commercial buildings), ASHRAE Standard 169 (climatic data for building design), ASHRAE Standard 62.2 (residential ventilation), the International Energy Conservation Code (IECC) provisions for residential buildings, and later editions/addenda of Standard 90.2 (the 2024 edition supersedes the 2018 edition).

Keywords

Residential energy standard; low‑rise residential; building envelope; HVAC; service water heating; lighting efficacy; airtightness verification; energy modeling; prescriptive path; performance path; ASHRAE 90.2; ANSI; IES.

FAQ

Q: What is this standard?

A: ANSI/ASHRAE/IES Standard 90.2-2018 is an American National Standard titled "Energy‑Efficient Design of Low‑Rise Residential Buildings" that sets minimum whole‑building energy performance requirements and provides prescriptive and performance compliance options for low‑rise residential buildings.

Q: What does it cover?

A: It covers building envelope requirements, HVAC and service‑water‑heating systems, lighting and controls, major appliances and service equipment, on‑site power considerations, verification (air‑leakage testing, commissioning/installation guidance), and compliance reporting for low‑rise residential buildings.

Q: Who typically uses it?

A: Architects, HVAC and lighting designers, energy modelers, builders and contractors, building code officials, utility program managers, and anyone involved in designing, verifying, or regulating energy performance of low‑rise residential construction.

Q: Is it current or superseded?

A: The 2018 edition is a historical edition. It has been superseded by a later edition (ANSI/ASHRAE/IES Standard 90.2-2024). Users working on current code adoption or recently updated programs should verify whether the 2018 or the 2024 edition (or local code adoption) applies in their jurisdiction.

Q: Is it part of a series?

A: Yes. Standard 90.2 is the ASHRAE standard specifically for low‑rise residential buildings and complements Standard 90.1 (which covers buildings other than low‑rise residential). The "90.x" family of standards addresses energy performance across different building types and related topics.

Q: What are the key keywords?

A: Energy efficiency, low‑rise residential, building envelope, HVAC, service water heating, lighting, airtightness, energy modeling, prescriptive path, performance path, ASHRAE 90.2.