On a blueprint, a plan gives a horizontal view of the construction from its top at 30 inches above the floor; what is this called?

A plan that provides a horizontal view of construction from above at a specific height, such as 30 inches above the floor, is termed a Floor Plan View. This type of drawing is commonly used in architecture to represent the layout of rooms, walls, doors, and other elements within a structure from a bird's-eye perspective. Floor plans are integral for understanding the spatial organization within a building and are typically drawn to scale.

An Elevation Plan shows vertical aspects of a building's exterior and does not provide a horizontal view. A Site Plan is used to indicate the layout of a site, including buildings, landscaping, and other features relative to the lot's boundaries, and it is not specifically focused on internal layouts. A Section View illustrates a cut-through of a building to show internal structures and spatial relationships, often in a vertical manner, rather than a top-down perspective. Thus, a Floor Plan View is the most appropriate term for the horizontal view described.