Before a contractor can prepare a quote for you they must do their homework. This includes making a visit to your property and talking with you, preferably face-to-face. They will need to survey the area to be irrigated, locate a water source and take a reading of the water pressure available at the property. Then, just as importantly, they need to discuss with you exactly what you want from your garden, to understand your needs and what it is you want to achieve from the watering system. You also need to feel comfortable with the contractor, especially with their level of experience and their expertise.
A reference from a recent customer is always helpful and can often allay any nagging doubts or concerns you may have.
Lastly, it is important to remember that it’s not all about price. Too often we use price as the only deciding factor when, in actual fact, a contractor who has significantly lower prices than his competition will have had to cut corners in order to reduce costs. This could mean leaving out a backflow-preventer, or not using the correct and proper installation techniques, or, worse still, not completing the work. Make sure you select a contractor based on the service offered, the ability to plan and design an efficient system, and the possession of the necessary experience and knowledge required to install the irrigation system to the highest standards.