Once the site for your custom-built home has been selected, the design process can begin. Builders caution against starting with a fixed idea of how your home should be designed because much of the design will be dictated by the characteristics and constraints of the site you've selected.

The custom design process involves talking about ideas for your home, evaluating options for your home's floor plan, reviewing preliminary conceptual designs and preparing working drawings and specifications, which are the written instructions for building your home.

Designing a home that will fit your budget is crucial to the project's success. Builders say the hardest part of the custom-home design and building process is matching buyers' needs and dreams with the realities of their budgets. The tendency is for the designer to stretch the size or specifications of the home beyond what is realistic in an effort to please the buyer. Having a builder's guidance and assistance will help keep the design within your budget.

Many buyers are inclined to try to save money in the home design stage, in part because these expenses can't be recouped if the project doesn't go forward for some reason. Builders advise against cutting corners at this point because a good design is truly the foundation of a well-built home for the following reasons:

1. Structural integrity. A basic element of a good design is making sure your new home won't be prone to structural deformities. The location of beams and posts, the routing of mechanical runs and chases and the engineering of the foundation all affect the home's strength, soundness and livability. Mechanical runs and chases are hidden spaces inside the walls and the floors that are needed for plumbing, electrical, HVAC (heating, ventilation and air-conditioning) and other home systems.

2. Aesthetic considerations. Your new home's curb appeal and floor plan are important not only for your enjoyment of the home, but also for the eventual resale of the home. A good design ensures a well-thought-out floor plan and takes the look and feel of the home into consideration. A good design is timeless.

3. Interpretation errors. A good design and working drawings will minimize errors resulting from the omission of details needed by the subcontractors, suppliers and job-site supervisors hired by the builder. Design errors increase construction costs for you and the builder.

4. Change orders. A plan that is well thought out and closely scrutinized by you and the builder will be subject to fewer costly changes during construction.

A successful home-building project requires a three-sided balance of the size, the cost and the quality of the home. No builder can construct a huge home of the highest quality for a bargain-basement price. Quality and size requirements determine the cost while budget constraints determine the size and quality. Having realistic expectations about the size and quality of the home your budget can accommodate will help you, the builder and the designer agree on a plan that will suit your needs and fit your budget.