IES RP-2

Description / Abstract: INTRODUCTION

This Recommended Practice is a revision of RP-2-01. It includes information on current lighting techniques and new lighting technology introduced since that date.

This revision emphasizes lighting quality and energy efficiency. In the past, the IES has always recommended illuminance for specific applications or visual tasks. Such recommendations were often mistaken as the sole criteria for lighting design. The Lighting Handbook, 10th ed.,¹ proposes a formal system for considering a wide range of lighting design criteria important for a high-quality visual environment. Chapter 34, Lighting for Retail, provides an overview of this new formal system for retail spaces. This document, RP-2-17, provides an in-depth discussion of the system and the criteria essential to lighting merchandise displays in a variety of retail applications. Specifically, lighting quality metrics appear in Tables 1 and 2. Horizontal and vertical illuminance, along with uniformity recommendations, can be viewed in Tables 3 and 4.

This Recommended Practice was written for designers with varying levels of experience in retail lighting design. The study of this Recommended Practice, including the references and annexes found at the back, should serve as a foundation for good retail and merchandise lighting. For optimum success in lighting retail spaces (or where specialized merchandise lighting is required), the services of a professional specializing in retail merchandise lighting design is recommended. Ideally, this lighting professional should join the design team during the early stages of project development.

Various energy codes are referenced in this document. Although these codes are periodically being updated, jurisdictions may choose to delay the adoption of the latest versions. Likewise, many jurisdictions make their own modifications to these codes. The adopted energy code in the project’s jurisdiction as well as its dated version should be identified at the beginning of the project.

Careful consideration should be given to visual cues, which will establish brand identity and convey the image a store wishes to project (see Figure 1). The lighting system should be designed to create a pleasant and secure environment for conducting business. When security is of particular concern for any given exterior environment, IES G-1-16, Security Lighting Guidelines for People, Property, and Critical Infrastructure,² is an excellent resource covering security lighting principles.

Sophisticated consumers and the deployment of fewer trained sales personnel make it essential to present various types of products and merchandise under lighting that will help increase sales. Thus, attention should be given to the quality, quantity, and effectiveness of lighting in rendering the color and detail of displayed merchandise or the task area.

New, more efficient light sources, innovative luminaire designs and updated controls equipment provide the designer with a vast array of tools to meet the ever-changing requirements of the retail world to promote brand identity while reducing operating costs and addressing energy and sustainability issues. The criteria and techniques presented in this Recommended Practice serve as a foundation for how to use these new tools.