Most of the homeowners prefer having large garages, but the harmony between the house design and the garage design is very important. The garage shouldn't overwhelm the existing home structure. Once the homeowner or the architect decides about the proportions between the existing home and the new garage addition, the next step is drawing some plans with different designs each fitting house's, and determining constructional materials.

Estimating the garage addition costs depends on the builder. If the builder is the homeowner, he/she should review with some subconstractors the plans and development schedule. Each subcontractor should provide a firm fixed estimate for the particular job based on the plans and bill of materials.

If the builder is a contractor, then costs will need to be calculated starting with the bill of materials. With a comprehensive bill of materials a homeowner can provide much of the list to any home improvement store where they can fill out the pricing information. For garage doors, garage door openers, lighting and plumbing fixtures the homeowner may need to contact specialty stores for pricing.

After having the plans and cost estimates the homeowner can then proceed with pulling permits and once permits have been approved, construction of the garage addition can begin.