### Outdoor Lighting Cost Estimation

#### A Simple Technique for Improving the Appearance and Security of Outdoor Lighting

Lighting designers and planners should check that their client's budget expectations match the likely costs of any project. To avoid wasting design time, designers must quickly approximate a project budget at the very beginning, often before any design is conceived or developed. Designers must also be able to explain what benefits, such as improved sense of security or appearance, the clients can expect for their investment in outdoor lighting.

A simple technique to plan preliminary budgets for the equipment, installation, and operating costs of outdoor lighting installations has been developed. The designer multiplies the area to be lighted by coefficients for cost per unit area. These coefficients are based on the intended level of improvement in appearance and sense of security for commercial, industrial, public, and residential lighting installations.

The coefficients were developed using the 108 lighting designs in The Outdoor Lighting Pattern Book. These designs upgraded and redesigned the lighting for 31 typical outdoor lighting scenes. Each design was evaluated for cost, illuminance, light distribution, color, site coverage, and power density and then rated for appearance and sense of security by an expert panel. The average costs of appearance and security improvements are presented as an initial planning tool for outdoor lighting.

#### An Example

The Central City Revitalization Committee is applying for a grant. Their objective is to improve the appearance of 24,000 square feet (sf) of the downtown area to attract people to downtown. How much should they budget, what are the continuing operation costs or savings for the city, and what difference could it make in appearance?

Assume the current downtown lighting is commercial space, poor in appearance, and the Revitalization Committee wishes to upgrade it to very good (an improvement in security of three points). A quick budget for the grant can be determined by multiplying \$.84/sf by the area, or about \$20,000. Considering the Committee is looking for a three-point improvement, the budget can be refined by multiplying 24,000 sf by the commercial installed cost per appearance point coefficient, \$0.31/sf, times three points of desired improvement, yielding a \$22,300 budget estimate. The committee can calculate the increased energy and maintenance cost for the city, totaling \$2880/yr (energy coefficient \$0.09 plus maintenance coefficient \$0.03 times 24,000 sf). If the grant application is unsuccessful, the Committee could also propose a bond for the installation. The three-point improvement in appearance will cost \$.07/sf/yr (annualized life cycle cost per appearance point) times three points times 24,000 sf, or \$5040 per year including the cost of the bond, energy, and maintenance. In addition to improving appearance, the sense of security in downtown Central City is also likely to increase.