How to coordinate irrigation, lighting and services before planting

Underground services share space with foundations, roots and drainage. Coordination avoids irrigation valve boxes in the middle of a trunk or cables laid where there should be continuous soil.

Irrigation, lighting, drainage, electrics, pools and architecture are laid over the same base drawing. Conflicts are resolved before excavation.

Main pipework and crossings go in before paving. Cables and final emitters are protected until planting.

Spare ducts allow future runs without destroying finishes.

The position takes account of the rootball and the future root volume. Boxes and rigid pipes should be kept away from the base.

When a root zone has to be crossed, the method is defined so as to reduce damage.

Zones correspond to needs and aspect. Valves are kept accessible, but away from paths and dense planting.

Spotlights are positioned with the growth of the planting, glare and maintenance in mind. Cables should not be left vulnerable to future digging.

Before backfilling, the services are photographed with reference points. The as-built drawings support maintenance.

Pressure, watertightness and circuits are tested before covering. Putting things right after paving costs more.

Irrigation, lighting, drainage, electrics and architecture should all work from the same topography and the same version of the design. Small differences in the base drawing put boxes, trees and paving in incompatible positions.

Each service needs to show its route, depth, size and maintenance access. At the most congested points, the sections are as important as the plan.

Pipes, foundations and boxes take up volume. So do a tree’s rootball and the soil it needs to grow.

Coordination should not stop at checking whether the lines cross on the drawing. You need to understand whether a trench cuts into the root zone, whether a box sits under the crown or whether a future repair will mean cutting structural roots.

Around pools and ponds, the density of services increases. Plumbing, lighting, drainage and the electrical supply need to be coordinated with trees, paving and access.

The plant room must remain accessible. Screening it with planting must not prevent it from being opened or ventilated, or equipment from being replaced.

The main services are installed and tested before the finishes. Photographs with reference points and as-built drawings make it possible to locate what will end up out of sight.

Spare ducts can avoid future demolition. The small cost of allowing for a run is generally lower than that of opening up finished paving.

The position of the services should make it possible to repair a valve or replace a cable without cutting structural roots or demolishing large areas of paving.

Boxes are kept accessible and labelled. The as-built drawings record routes and approximate depths, accompanied by photographs taken before backfilling.

Allowing for spare ducts at strategic points can avoid fresh excavation when the garden is given lighting, automation or other equipment in the future.

• Detailed design
• Stages of a build

1. Principles for coordinating disciplines and recording services.
2. Diaplant’s method for coordinating design and site work.