Chapter on the Rulings Governing the Sale of al-uṣūl (principal real property)

Al-uṣūl are dwellings, plots of land, and trees. When such property is sold, everything that is inseparably attached to it and serves its purpose passes to the purchaser, whereas whatever is not considered an appurtenance remains the seller’s. Knowing this distinction puts an end to disputes between the two parties, for each then understands precisely what is his and what is not. Our religion has not left any matter that brings us benefit or wards off harm without clarifying it; once its rulings are applied, there is no room for contention or litigation. What we are about to discuss is a case in point: a person may sell something he owns that has adjuncts, complements, and facilities, or that yields produce—whether still attached or already detached. A disagreement may then arise between the contracting parties as to which of them is entitled to those adjuncts. To adjudicate such questions, the jurists have devoted a special section of Islamic law called “The Chapter on the Sale of al-uṣūl and Their Fruits,” in which they laid out these rulings.

Thus, if someone sells a house, the sale includes its structure and roof, for both are encompassed by the very term “house.” It likewise includes whatever is fixed to the house for its benefit: installed doors, staircases, shelves nailed in place, built-in machinery such as lifts, electrical fixtures, hanging lamps for lighting, and storage tanks