With the recent changes in multi-unit housing, improvement is needed in terms of efficient maintenance of the housing facility system. The purpose of this study is to examine the technical possibilities for the integration and development of heating, hot water, and water facilities, and to derive the design direction of the district heating heat interface unit (HIU). In order to derive the integration direction of the district heating HIU as a research method, the relevant standards and the status of facilities in domestic MDUs (Multi Dwelling Unit) and overseas case studies were conducted. The conclusion is as follows. In general, most of the hot water distributors are installed at the bottom of the kitchen sink and the gas meters are installed on the balcony. If it is integrated into the HIU, it is most suitable to install it in a common PD space, and for this, it is necessary to secure enough PD space architecturally.