House plans are generally not considered public record unless they have been filed with a government agency as part of a building permit application. Once filed with a government agency, the plans may become part of the public record and could potentially be available for public inspection, subject to any privacy laws or other restrictions that may apply.
However, in most cases, house plans are considered private property and are protected by copyright law. If you are looking for house plans for a specific property, you may be able to obtain them from the property owner or through a licensed architect or builder who has access to the plans. However, you should be aware that reproducing or using the plans without the owner's permission could be a violation of copyright law.