A home in a shared building is not one property under one owner. A condominium, a townhouse, or a multi-unit building often splits the systems between the unit owner and an association. A contract written for a detached house may not match that split, so check the fit before you choose a term.
Map each system to its owner
List the systems you want to cover and, for each one, note whether it sits wholly inside your unit, in a shared space, or in a wall or line that serves more than one unit. Check the association's governing documents for who owns and who must repair each item. Write the answer next to each system on your list.
Compare the list to the contract
Look at how the contract names the covered items. Some papers list items by type, some by location, and some by model. Check whether an item outside your unit, or one the association must repair, falls inside the paper's terms. Ask the seller how the contract treats items the owner does not control, and get the answer in writing.
Check the notice and consent steps
Some associations require notice before work is done on a shared system, or require approval for a contractor. Find out whether the contract's dispute steps and repairer steps can be carried out without that approval, and whether a delay for approval affects the term.
Check the association's own coverage
Ask whether the association already carries a warranty or service arrangement on any shared system. Overlap between the association's paper and the contract is a fit question you should settle before you sign.
State rules
This guide has not read the rules of every state, and it does not say how any state treats shared-building systems. Each state page on this site names the regulator and cites the statute or program that page has read, and says whether a roster exists. Read the page for your state before you rely on a rule for a unit in a shared building.