Project Design 

Like all projects, time invested in careful design and planning will lead to an installation that is effective and efficient. It is the only way to ensure that all of the lighting objectives are met at the lowest cost. In this chapter we will discuss the design and planning process and the tools that make the job fast and accurate.

The design and planning process follows the following steps:

·        Determining the lighting objectives

·        Drawing a site plan

·        Select the lighting technique

·        Lamp and fixture selection

·        Circuit Design and Transformer Selection

Prior to starting the plan you should check with the local zoning department or building official to find out if there are any ordinances that pertain to outside lighting. Some localities have enacted laws designed to reduce light pollution which sometimes includes residential landscape lighting. There’s no point in designing a project only to find that it cannot be implemented because of local codes.

Lighting Objectives 

The first step is to determine what you are trying to accomplish with lighting. In the first chapter we stated that we light for safety, security, aesthetics, and tasking. The first step in the plan is to write down which of these purposes we are trying to address. Quite often the plan will have multiple objectives, even all four purposes. It will be very helpful to make an initial site survey, making notes of all the areas and objects that need light. This can be approached several different ways. The one presented here divides the property to be lit into zones and notes the needs under each purpose as illustrated by the following example:

Example of an Initial Lighting Survey

This initial site survey should be done without much emphasis on cost or difficulty. Certainly most projects have to be managed within a budget; however, it is a good idea to start with a complete wish list. Often, several objectives can be accomplished with the same fixtures if carefully selected.

If there is an overall budget limitation, the last step of determining the lighting objectives is to assign a priority ranking to all of the needs that were identified in the initial site survey. Safety and security issues usually receive the highest priority. Until the lamp layout and component selection is complete, the cost of the project will only be a rough estimate. Having set a priority ranking for each objective will help in determining how many and the type of fixtures that are selected for the project. 

Site Plan 

For all but the smallest projects, a scaled site plan is a very important system design tool. Fortunately for most properties a lot of the work in developing a site plan is already complete. Most properties built in the past few decades have a plat of the property that was drawn by a land surveyor. Depending on the size of the property, these plats are scaled drawings with the house, outbuildings, and decks and porches located and measured. Other property measurements and physical features are also included on the plat such as the driveway, sidewalks, and bay windows.

The typical scale used for a residential property plat is 1” = 30’, although other scales are used. Additionally, many municipalities are now requiring measurements using the metric system. If the scale is too small to work with accurately, the plat can be enlarged with a copier that has a reduction/enlargement feature and can handle tabloid size paper (11” x 17”.) Copy centers like Kinko’s have this type of copy machine. Make several copies in order to draw alternative plans. 

Once you have a copy of the plat with a workable scale, you will have to locate the objects and areas identified in the initial site survey on the plat. This will include all plant related items such as beds and trees. Features such as small ponds may be on the plat, but frequently they are not. The location of these added features needs to be accurate within a foot or so. Too much error could lead to material shortages and inadequate power to outlying fixtures.