Thinking about building or remodeling—and want to be sure it’s as green as you can make it? As with any major purchase, you must do your homework. Even a small contracting job can cause headaches and financial losses if not researched properly. And finding the right contractor is absolutely crucial.

“Green” contractors are trained to build and/or design projects that are energy-, water-, and resource-efficient, as well as employing methods to ensure proper indoor ventilation. Unfortunately, most contractors don’t have this type of training and aren’t sure where to shop for materials. Your best bet is to seek out a contractor who has been designated a Master Builder by the Energy and Environmental Building Association or has been certified by the National Association of the Remodeling Industry as a Certified Remodeler. If you can’t find a certified contractor but are lucky enough to have a contractor who is willing to work with you, then you can do your own research on green building by checking out Green Building: A Primer for Builders, Consumers, and Realtors at EnergyBuilder.com/greenbld.htm.

When choosing a contractor, the following guidelines should help you make a good decision.

Prepare. Read magazines and books, visit green building materials stores, surf the Web.

Decide how to approach the project. There are two types of contractors: general contractors and trade contractors. A general contractor is a project coordinator who is responsible for hiring and supervising the work performed by trade contractors. Trade contractors are specialists who work on individual aspects of the job such as electrical or plumbing. Most green contractors are general contractors. However, if your general contractor doesn’t see green, you may have to work in partnership to ensure that he or she is buying the right products.

Ask friends and neighbors for referrals. Not only can you see the contractor’s work firsthand, but you can also check whether the work was done on time and on budget. Ask if the contractor was responsive and courteous. Were the homeowners consulted about the materials used? Was the contractor communicative and willing to listen? If you live in an area served by a green retailer, ask for a referral.