U.S. Department of Energy - Energy Efficiency and Renewable Energy

Building Technologies Program – Building America

Performance Analysis

Performance Analysis resources enable Research Teams to compare the energy performance of actual houses against a standard or benchmark house. This ensures homes achieve the goals set using the systems engineering approach. Here you will find information about the house simulation protocols established by Building America. These resources are available as Adobe Acrobat PDFs. Download Adobe Reader.

Building America House Simulation Protocols

Building America Research Teams evaluate cost and performance trade-offs through a series of controlled field and laboratory experiments supported by energy analysis techniques that use test data to inform energy simulation models.

The steps involved in performance analysis include defining a reference building, measuring the actual performance of a house, and determining the energy savings. Building America developed the House Simulation Protocols report (PDF 1.3 MB) to assist in this process. This report also describes analysis procedures that provide the basis for:

• Calculating the whole-house energy savings of a post-retrofit or New Construction Test Home (NCTH) relative to three important base cases: the Building America Research Benchmark, Builder Standard Practice, and Regional Standard Practice
• Using building simulation analysis to calculate annual energy savings based on side-by-side short-term field testing of a prototype house and reference house
  • The reference building for New Construction is the Building America Benchmark building which is consistent with a 2010 home that follows the latest codes and standards. 
  • The reference building for existing homes is as consistant with the pre-retrofit house as possible. This document gives default values for any system of the home that cannot be measured.
• Comparing analyses to field-test results.

The report is broken up into three sections, New Construction, Existing Homes, and Operating Conditions.

New Construction

To track progress toward aggressive multi-year, new construction, whole-house energy savings goals of 30% to 50%, Building America developed a Research Benchmark building in consultation with the Building America teams. This benchmark acts as a reference building for new construction test houses, and has recently been updated to be generally consistent with construction practices from 2010.

Existing Homes

In addition, Building America provides a set of guidelines for estimating the energy savings achieved by a package of retrofits or an extensive rehabilitation of an existing home. This report outlines a set of typical operating conditions that will be used for the purpose of using a building simulation model to compare energy use before and after a series of retrofits are completed.

Certain field test and audit methods are also described or referenced in this report. These tests help establish accurate building system performance characteristics that are needed for a meaningful simulation of whole-house energy use. Several sets of default efficiency values have also been developed for certain older appliances that cannot be easily tested and for which published specifications are not readily available.

Note: Before Building America research team members implement retrofit measures on an existing home, health and safety concerns must be addressed in accordance with the Building America Retrofit Participation Requirements and Release document (PDF 43 KB).

Operating Conditions

The operating conditions listed in the report give detailed definitions and use profiles for all end-use categories. These operating conditions apply to all simulations conducted for official Building America reporting purposes, including the analysis of both new homes and retrofits of existing homes, unless otherwise specified.

Related Links

Following is a list of useful Performance Analysis links:

• Air Conditioning Contractors of America
• Air Conditioning Contractors of America Manuals
• BESTEST—Building Energy Simulation TEST
• BESTEST–EX—Test Procedure for Existing Homes
• Building Energy Simulation User News—See Vol. 19 for DOE2 training
• California Title 24 – California Energy Commission
• U.S. Department Of Energy (DOE) Building Energy Software Tools
• DOE2.1E and 2.2
• Energy Information Administration
• EnergyPlus Energy Simulation Software
• Home Energy Rating System (HERS)
• Typical Meteorological Year Data—From the National Renewable Energy Laboratory
• DOE's Appliances and Commercial Equipment Standards
• DOE's 1997 Residential Energy Consumption Survey (Published November 1999)
• DOE's Technical Support Document: Energy Efficiency Standards for Consumer Products: Residential Water Heaters, Appendix D-2 (December 2000)
• DOE's Residential Integrated Code Change—Energy Conservation Code change proposal