A person who is professionally trained and licensed to examine the eyes for visual defects, diagnose problems or impairments, and prescribe corrective lenses or provide other types of treatment.
1 Adding a basement to an existing house can cost $30,000-$70,000 or more, depending on the size of the existing crawlspace or half-basement or if the house is on a slab foundation, and how much of the work is do-it-yourself and how much is done by contractors. Having a prefabricated safe room (a welded steel box, a steel skeleton with steel planks or a prefabricated unit that is bolted together on site) installed in a basement can cost $3,000-$20,000 or more, depending on materials and size.
1 A slab foundation for an average 1,600- to 1,800-square-foot family home might cost about $7,000-$16,000 or more, while a slab foundation for a 3,000- to 4,500-square-foot home might cost $13,000-$40,000 or more. Typically footers are poured along with short walls that support the home; some crawl spaces provide only 16-18 between the bottom of the floor joists and the soil, while others are tall enough to crouch inside. 2  Build Your Own House explains the pros and cons of a crawl space foundation.