Nadbudow

Nadbudow is a term used in Polish-language architecture and construction to describe the process of constructing additional structure on top of an existing building, effectively creating a vertical extension. In many sources it appears as nadbudowa, which denotes the resulting addition or the act of adding floors. Nadbudow is thus linked to the concept of a superstructure, and it is distinct from rozbudowa, which generally denotes expansion of a building's footprint or volume, often by extending laterally.

Common forms include adding one or more floors, converting an attic into habitable space by raising the roof or altering its shape, and installing rooftop structures such as penthouse levels or mechanical rooms. The goal is to increase usable floor area without enlarging the building's footprint.

Design and construction require careful assessment of structural capacity, foundation load transfer, and potential impacts on stability. Engineering considerations include load redistribution, seismic and wind resistance, fire safety, egress, moisture control, and insulation. Utilities (water, sewer, heating or cooling, electrical) must be extended or redirected, and waterproofing must be maintained at interfaces with old and new elements.

Regulatory issues include zoning, permits, and, when applicable, restrictions for historic buildings or protected skylines.

Applications include urban densification, modernization of older housing stock, and upgrades of commercial properties. In historic districts, nadbudowa projects may be subject to additional design review to maintain architectural character.