A Study of Compliance with the Lighting Provisions of the Minnesota State Building Code for Small Commercial Buildings


Building energy use is a substantial part of the nation's total energy use, and a majority of commercial building energy use is for lighting and lighting-related cooling, making it a prime candidate for energy efficiency measures and minimum efficiency building code standards. Previous studies have found that lighting improvements account for a large share of the potential savings from energy codes, however studies also indicate that the mere enactment of codes is not sufficient to produce a high degree of code compliance.

In an effort to improve code compliance, the Minnesota Department of Public Service (DPS) instituted a series of informational seminars on the lighting portion of the state building energy code for designers, contractors, and code officials. They also commissioned the present study to determine the current levels of awareness of the energy code and compliance with it and to assess the impact of the seminars on awareness and compliance. The first phase of this study involved two telephone surveys that were administered to lighting designers and contractors and to code officials. The second phase involved plan reviews and site visits to determine the code compliance of a sample of recently constructed commercial buildings.

The survey results followed a fairly consistent pattern in which the highest familiarity with various aspects of the lighting code, the state compliance forms, and the DPS seminars was found among designers, followed by contractors and then code officials. Claimed levels of familiarity with the code were quite high, but inappropriate answers to specific code questions and the high marks given to the seminars for further increasing their knowledge indicate that their familiarity may have been over-stated. Firms that were aware of the seminars were very likely to have sent someone, and attendees gave high marks to the seminars as informational vehicles (though not quite so high as significant influences on their subsequent compliance practices). However, the rate of attendance was low enough among the entire respondent group that the seminars were given low marks overall for their influence on current practices.

All respondent groups reported substantial changes in lighting design practices since the current code was enacted in 1992, with adoption and enforcement of the code, utility rebate programs, falling prices for efficient equipment, and general shifts in industry practices all named as factors causing that change. The principal types of changes included increased use of T8 fluorescent bulbs, electronic ballasts, compact fluorescent lamps, occupancy sensors and photosensors, and increased spacing of fixtures. All three groups estimated current compliance rates at about 50%, which closely matches the observed rate of plan review compliance with the power density requirements but is somewhat higher than the corresponding power density compliance rate for site visit cases (and much higher than the overall site visit compliance rate when control requirements are also taken into consideration). The list of cities thought by designers and contractors to have enforcement procedures in place and the responses by code officials about whether their own cities have such procedures were strikingly inconsistent, which was probably due mostly to misunderstanding and errors, but could also have involved some differences of opinion about just what constitutes enforcement. There was much more unanimity regarding the changes needed to increase compliance. Each group surveyed believed that there needs to be more (and more uniform) enforcement supported by adequate funding, more training and notification of all involved parties, and modification of the code to make it clearer and simpler to apply. There were enough complaints about particular code limitations to suggest that the power density and control standards be reviewed in order to better match industry practices and customer desires in a number of specific building classes.

A sample of 40 commercial buildings was recruited that was split between firms that did or did not participate in the seminars and between the periods before and after the seminar, with matching by design firms and building types. The overall compliance rate was 50% from plan reviews and 42% from site audits based on allowable wattages per square foot, results that are roughly comparable with the survey estimates of overall compliance in the state. Including the lighting control standards lowered those rates further to 10% and 14%, respectively. There were no significant differences by participant status or time, so the training did not appear to have had an immediate effect on compliance. There was a suggestive but marginally non-significant difference in compliance rates by building types.

There appears to be some need for further education of designers and contractors about the code and what is involved in designing to meet it, but the training should probably have more hands-on detail and be separately tailored to the different groups. Design and code compliance training may be best targeted at contractors with limited design staff resources and expertise, but it would need to be delivered in a focused and low cost manner to be cost effective. Previous studies suggest that it would not be too difficult for designers and contractors to meet the code, requiring only a few changes in typical design practices and the specification of a few types of state of the art equipment rather than the traditionally used equipment.

There appears to be a greater need to educate code officials, but an equally important barrier to greater enforcement is the lack of funding and support needed to carry out energy code enforcement in addition to their other tasks in times of common cut-backs of funding and staffing. To the extent that code officials have a tendency not to consider the energy code an important part of their job, it would perhaps be more useful to develop ways to fund the use of specialized contract employees for energy code checking. This and other initiatives could be funded in part from utility Conservation Improvement Program (CIP) funds if the regulatory resistance to using such funds to ensure code compliance could be overcome. Another funding mechanism (and compliance incentive) might be to have differential hook-up fees for new buildings based on their energy efficiency.

Full report (PDF)
A Study of Compliance with the Lighting Provisions of the Minnesota State Building Code for Small Commercial Buildings