A storage water heater: Review its dimensions and first-hour rating as well as tank capacity. First-hour rating describes how much hot water a fully heated tank can supply over an hour. It helps compare the equipment with the household's expected demand.
A tankless water heater: A wall-mounted unit can change the floor-space arrangement, but its water, energy and vent connections still need planning. Output must suit the fixtures likely to run together and the temperature rise needed at the property.
A heat pump water heater: This type draws heat from surrounding air. Available air volume, room temperature, operating sound and condensate drainage all affect suitability. A closet or enclosed utility area needs evaluation against the particular model's requirements.
The surrounding room: Leave the installation plan open until the removal route, working clearances and connection access have been reviewed. Cabinetry or a new partition should be coordinated with those requirements, including any other appliances sharing the area.