Abstract: This document is the final deliverable for Project 2.2 - Retrofit Tools, in the California Energy Commission Public Interest Energy Research Program for High Performance Commercial Building Systems (PIER-HPCBS). The objective of Project 2.2 is to deliver an updated and California-Customized retrofit analysis tool based on the earlier federally funded RESEM (Retrofit Energy Savings Estimation Method) tool. Specific tasks to accomplish this were identified in PIER HPCBS Report # E2P2.2T1c [see references], and addressed (a) modernization, (b) enhancement of basic analysis methods and capabilities, (c) adding, modifying, or updating databases for California building types, systems, components, utility rate structures, and weather.

Abstract: Energy per unit of floor area is not an adequate indicator for energy efficiency in high electric-load buildings. For two activities, restaurants and computer centres, alternative indicators for energy efficiency are discussed.

Abstract: This report documents the results of an extended comparison of RESEM-CA energy and economic performance predictions with the recognized benchmark tool DOE2.1E to determine the validity and effectiveness of this tool for retrofit design and analysis. The analysis was a two part comparison of patterns of (1) monthly and annual energy consumption of a simple base-case building and controlled variations in it to explore the predictions of load components of each program, and (2) a simplified life-cycle cost analysis of the predicted effects of selected Energy Conservation Measures (ECMs). The study tries to analyze and/or explain the differences that were observed.

On the whole, this validation study indicates that RESEM is a promising tool for retrofit analysis. As a result of this study some factors (incident solar radiation, outside air film coefficient, IR radiation) have been identified where there is a possibility of algorithmic improvements. These would have to be made in a way that does not without sacrifice the speed of the tool, necessary for extensive parametric search of optimum ECM measures.

Abstract: Buildings often do not perform as well in practice as expected during pre-design planning, nor as intended at the design stage, nor even as measured during commissioning and maintenance operations. While this statement is generally considered to be true, it is difficult to quantify the impacts and long-term economic implications of a building in which performance does not meet expectations. This leads to a building process that is devoid of quantitative feedback that could be used to detect and correct problems both in an individual building and in the building process itself.

A key element in this situation is the lack of a standardized method for documenting and communicating information about the intended and actual performance of a building. This deficiency leads to several shortcomings in the life-cycle management of building information. Planners have no means of clearly specifying their expectations. Designers do not concisely document their design intent. Commissioning personnel have no standardized method for documenting the results of performance testing. Post-occupancy building performance cannot readily be compared to expectations in an attempt to evaluate and improve design and operation decisions. Lastly, without quantification of the magnitude of performance problems it is difficult to motivate building process participants to alter their current practice.

This document describes an information management concept and a prototype tool based on this concept that has been developed to address this situation. The Building Life-cycle Information System (BLISS) has been designed to manage a wide range of building related information across the life cycle of a building project. Metracker is a prototype implementation of BLISS based on the International Alliance for Interoperability"s (IAI) Industry Foundation Classes (IFC). The IFC is an evolving data model under development by a variety of architectural, engineering, and construction (AEC) industry firms and organizations (IAI, 2001). Metracker has been developed to demonstrate and explore the process of tracking performance metrics across the building life cycle.

Abstract: Buildings often do not perform as well in practice as expected during pre-design planning, nor as intended at the design stage. While this statement is generally considered to be true, it is difficult to quantify the impacts and long-term economic implications of a building in which performance does not meet expectations. This leads to a building process that is devoid of quantitative feedback that could be used to detect and correct problems both in an individual building and in the building process itself. One key element in this situation is the lack of a standardized method for documenting and communicating information about the intended performance of a building. This paper describes the Building Life-cycle Information System (BLISS); designed to manage a wide range of building related information across the life cycle of a building project. BLISS is based on the Industry Foundation Classes (IFC) developed by the International Alliance for Interoperability. A BLISS extension to the IFC that adds classes for building performance metrics is described. Metracker, a prototype tool for tracking performance metrics across the building life cycle, is presented.

Abstract: This paper is about a theoretical framework of the relationship between digital media and architecture. The objective of the paper is to better understand the nature of change that digital media bring and the ways they affect architecture, leading to a vision of how the profession might be practiced in the future.

Three design models are presented, addressing the design tasks, the types of information used and the interaction among design participants. Digital media are examined with respect to the fundamental nature of their contribution to society in general and architectural practice in particular, concluding that, at an abstract level, the main contribution of digital media is increased speed in the production of analog media. This increase in speed, however, is so large that it presents significant opportunities to greatly improve the way we design, construct and operate buildings.

The three design models are combined into one that facilitates the development of digital applications. The opportunities that digital media present are then described in detail, within the theoretical framework of the new model and a vision is presented for what is possible not only for building design, but for construction and operation as well.

While the vision is based on technologies that are already available, its realization requires significant research and development efforts. Conceptual, technical and strategic challenges to realizing the vision are presented and discussed.

Abstract: In order to produce a new generation of green buildings, it will be necessary to clearly identify their performance requirements, and to assure that these requirements are met. A long-term goal of our program is to provide building decision-makers with the information and tools needed to cost-effectively assure the desired performance of buildings, as specified by stakeholders, across the complete life cycle of a building project. A key element required in achieving this goal is a method for explicitly documenting the building performance objectives that are of importance to stakeholders. Such a method should clearly define each objective (e.g., cost, energy use, and comfort) and its desired level of performance. This information is intended to provide quantitative benchmarks useful in evaluating alternative design solutions, commissioning the newly constructed building, and tracking and maintaining the actual performance of the occupied building over time.

We refer to these quantitative benchmarks as performance metrics, and they are a principal element of information captured in the Building Life-cycle Information SyStem (BLISS) [Hitchcock, et al., 1997]. Metrics can be flexibly defined within the BLISS framework for a wide spectrum of objectives that building process participants wish to specify and track. In addition to performance metrics, BLISS contains a standardized data model that captures a detailed description of the building designed to achieve the specified objectives. This information is meant to be maintained and shared by building process participants across the complete life cycle of a building project. Participants will make use of the specific information within the overall data model that is relevant to the task at hand, such as design, commissioning, facility maintenance, and performance tracking.

An initial implementation of BLISS is based on the International Alliance for Interoperability"s (IAI) Industry Foundation Classes (IFC), an evolving data model under development by a variety of architectural, engineering, and construction (AEC) industry firms and organizations [IAI, 1997]. Within BLISS, the IFC data model has been extended to include performance metrics and a structure for archiving changing versions of the building information over time. This paper defines performance metrics, discusses the manner in which BLISS is envisioned to support a variety of activities related to assuring the desired performance of a building across its life cycle, and describes a performance metric tracking tool, called Metracker, that is based on BLISS.

Abstract: Commercial buildings account for over $85 billion per year in energy costs, which is far more energy than technically necessary. One of the primary reasons buildings do not perform as well as intended is that critical information is lost, through ineffective documentation and communication, leading to building systems that are often improperly installed and operated. A life-cycle perspective on the management of building information provides a framework for improving commercial building energy performance.

This paper describes a project to develop strategies and techniques to provide decision-makers with information needed to assure the desired building performance across the complete life cycle of a building project. A key element in this effort is the development of explicit performance metrics that quantitatively represent performance objectives of interest to various building stakeholders.

The paper begins with a discussion of key problems identified in current building industry practice, and ongoing work to address these problems. The paper then focuses on the concept of performance metrics and their use in improving building performance during design, commissioning, and on-going operations. The design of a Building Life-cycle Information SyStem (BLISS) is presented. BLISS is intended to provide an information infrastructure capable of integrating a variety of building information technologies that support performance assurance. The use of performance metrics in case study building projects is explored to illustrate current best practice. The application of integrated information technology for improving current practice is discussed.

Abstract: Many building simulation computer programs, originally developed on mainframe computers for research purposes, can now run on the powerful workstation and personal computers that are available to most architectural and engineering firms. Major efforts have been underway during the last decade to compile these programs on personal computers and make them available to a wider range of building professionals. However, even with the addition of user-friendly front- and back-ends, their use is still limited to a small number of specialized consultants. Considering the tremendous benefits of informed decisions that these programs can support, it is critical to address and resolve the issues that are associated with their limited acceptance.

In this paper, we report on our research and development efforts to better understand decision-making and develop computer tools that will facilitate the use of simulation software during the building design process. We present a brief analysis of decision-making and then describe how we try to address it in building design through the development of the Building Design Advisor (BDA). Moreover, we elaborate on the major issues that we have encountered, discuss lessons learned, and offer recommendations for short- and long-term developments in this area.

Abstract: Industry Foundation Classes (IFC) provide an environment of interoperability among IFC-compliant software applications in the architecture, engineering, construction, and facilities management (AEC/FM) industry. They allow building simulation software to automatically acquire building geometry and other building data from project models created with IFC-compliant CAD software. They also facilitate direct exchange of input and output data with other simulation software.

This paper discusses how simulation software can be made compliant with version 1.5 of the IFC. It also describes the immediate plans for expansion of IFC and the process of definition and addition of new classes to the model.

Abstract: The Building Design Advisor (BDA) is a software environment that supports the integrated use of multiple analysis and visualization tools throughout the building design process, from the initial, conceptual and schematic phases to the detailed specification of building components and systems. Based on a comprehensive design theory, the BDA uses an object-oriented representation of the building and its context, and acts as a data manager and process controller to allow building designers to benefit from the capabilities of multiple tools.

The BDA provides a graphical user interface that consists of two main elements: the Building Browser and the Decision Desktop. The Browser allows building designers to quickly navigate through the multitude of descriptive and performance parameters addressed by the analysis and visualization tools linked to the BDA. Through the Browser the user can edit the values of input parameters and select any number of input and/or output parameters for display in the Decision Desktop. The Desktop allows building designers to compare multiple design alternatives with respect to multiple descriptive and performance parameters addressed by the tools linked to the BDA.

The BDA is implemented as a WindowsR-based application for personal computers. Its initial version is linked to a Schematic Graphic Editor (SGE), which allows designers to quickly and easily specify the geometric characteristics of building components and systems. For every object created in the SGE, the BDA activates a Default Value Selector (DVS) mechanism that selects "smart" default values from a Prototypes Database for all non-geometric parameters required as input to the analysis and visualization tools linked to the BDA. In addition to the SGE that is an integral part of its user interface, the initial version of the BDA is linked to a daylight analysis tool, an energy analysis tool, and a multimedia, Web-based Case Studies Database (CSD). The next version of the BDA will be linked to additional analysis tools, such as the DOE-2 (thermal, energy and energy cost) and RADIANCE (day/lighting and rendering) computer programs. Plans for the future include the development of links to cost estimating and environmental impact modules, building rating systems, CAD software and electronic product catalogs.

Abstract: The Building Design Advisor (BDA) is a software environment that supports the integrated use of multiple analysis and visualization tools throughout the building design process, from the initial, conceptual and schematic phases to the detailed specification of building components and systems. Based on a comprehensive design theory, the BDA uses an object-oriented representation of the building and its context, and acts as a data manager and process controller to allow building designers to benefit from the capabilities of multiple tools.

The BDA provides a graphical user interface that consists of two main elements: the Building Browser and the Decision Desktop. The Browser allows building designers to quickly navigate through the multitude of descriptive and performance parameters addressed by the analysis and visualization tools linked to the BDA. Through the Browser the user can edit the values of input parameters and select any number of input and/or output parameters for display in the Decision Desktop. The Desktop allows building designers to compare multiple design alternatives with respect to multiple descriptive and performance parameters addressed by the tools linked to the BDA.

The BDA is implemented as a WindowsR-based application for personal computers. Its initial version is linked to a Schematic Graphic Editor (SGE), which allows designers to quickly and easily specify the geometric characteristics of building components and systems. For every object created in the SGE, the BDA activates a Default Value Selector (DVS) mechanism that selects smart default values from a Prototypes Database for all non-geometric parameters required as input to the analysis and visualization tools linked to the BDA. In addition to the SGE that is an integral part of its user interface, the initial version of the BDA is linked to a daylight analysis tool, an energy analysis tool, and a multimedia, Web-based Case Studies Database (CSD). The next version of the BDA will be linked to additional analysis tools, such as the DOE-2 (thermal, energy and energy cost) and RADIANCE (day/lighting and rendering) computer programs. Plans for the future include the development of links to cost estimating and environmental impact modules, building rating systems, CAD software and electronic product catalogs.

Abstract: The Building Design Advisor (BDA) is a software environment that supports the integrated use of multiple analysis and visualization tools throughout the building design process, from the initial, schematic design phases to the detailed specification of building components and systems. Based on a comprehensive design theory, the BDA uses an object-oriented representation of the building and its context, and acts as a data manager and process controller to allow building designers to benefit from the capabilities of multiple tools.

The BDA provides a graphical user interface that consists of two main elements: the Building Browser and the Decision Desktop. The Browser allows building designers to quickly navigate through the multitude of descriptive and performance parameters addressed by the analysis and visualization tools linked to the BDA. Through the Browser the user can edit the values of input parameters and select any number of input and/or output parameters for display in the Decision Desktop. The Desktop allows building designers to compare multiple design alternatives with respect to any number of parameters addressed by the tools linked to the BDA.

The BDA is implemented as a Windows-TM-based application for personal computers. Its initial version is linked to a Schematic Graphic Editor (SGE), which allows designers to quickly and easily specify the geometric characteristics of building components and systems. For every object created in the SGE, the BDA supplies smart default values from a Prototypical Values Database (PVD) for all non-geometric parameters required as input to the analysis and visualization tools linked to the BDA. In addition to the SGE and the PVD, the initial version of the BDA is linked to a daylight analysis tool, an energy analysis tool, and a multimedia Case Studies Database (CSD). The next version of the BDA will be linked to additional tools, such as a photo-accurate rendering program and a cost analysis program. Future versions will address the whole building life-cycle and will be linked to construction, commissioning and building monitoring tools.

Abstract: A key impediment to improving the energy efficiency and reducing the environmental impact of buildings is the complexity and cost of managing information over the life cycle of a building. A surprisingly large fraction of the total cost of buildings is embodied in the decision making and information management process due to the structure of the building industry, the numerous people and companies involved in the process, the current nature of the building acquisition process, and the long time periods over which buildings operate once design and construction are completed. We suggest that new interoperable software tools could greatly facilitate and rationalize this complex process, thereby reducing time and cost, and greatly improving the habitability and environmental impact of these buildings. We describe a series of projects in which we are building and testing several prototype toolkits as part of a building life-cycle information system that will allow interoperable software tools to function more effectively throughout the design, construction, commissioning, and operations phases.

Abstract: Most currently available computer tools for the building industry proffer little more than productivity improvement in the transmission of graphical drawings and textual specifications, without addressing more fundamental changes in building life-cycle information management. This paper describes preliminary research into the development of a framework for the documentation and communication of the project objectives of a building project. When implemented in an interactive networked environment, this framework is intended to promote multiple participant involvement in the establishment and use of a common set of explicit goals, from the earliest phase of a project throughout its life cycle. A number of potential applications for this framework are identified. The requirements for integrating this life-cycle information with a product model of the physical design of a building, in an attempt to document and communicate design intent, are also discussed.

Abstract: The design and implementation of a computer-based Building Design Support Environment (BDSE) is described. The structure and operation of the BDSE is derived from a detailed analysis of the building design process, based on three basic iterative and interactive activities, i.e., the formulation of design criteria, the generation of potential solutions, and their evaluation. These three activities are fundamentally different with respect to the type of the required knowledge and the degree to which they can be specified and delegated to a computer. As a result, a variety of design tools are implemented for each activity and integrated into the BDSE. The different types of knowledge associated with each activity are used to determine the level of automation and the interaction between the designer and the computer.

A demonstration version of the BDSE addresses the design of the fenestration and the electric lighting system of office spaces with respect to comfort, energy, and cost. While this demonstration version is limited with respect to modeling capabilities and accuracy, it covers all types of design activities through the use of various tools, such as Issue-Based Information Systems, Expert Systems, Simulation Algorithms, Electronic Handbooks, Product Catalogs, and Case Studies. All tools are integrated within a multimedia-based environment that supports interactive use of computer graphics, electronic images, sound, animation and video.

Abstract: RESEM, the Retrofit Energy Savings Estimation Model, is a PC-based tool that will allow Department of Energy (DOE) Institutional Conservation Program (ICP) staff and participants to reliably determine the energy savings directly caused by ICP-supported retrofit measures implemented in a building. RESEM incorporates several innovative techniques into an interactive tool designed to ease completion of this demanding analytical task. For maximum accuracy and validity, energy savings are calculated directly from actual utility data, with sophisticated corrections for weather and use variations between the pre-retrofit and post-retrofit utility data collection periods.