Three-unit townhouse development, Illinois

Three three-storey townhouses, unit types A, B and C, each with a garage on the ground floor. The design covers heating, cooling and ventilation, water supply, sanitary drainage and gas piping for each unit.

MEP design and construction drawings.

• A gas furnace with a heat pump for each unit: 60,000 BTU/h cooling, 100,000 BTU/h heating and 2,000 CFM airflow.
• Ventilation to IMC 2021 Equation 403.3.2.1: 1,877 ft² and three bedrooms need 48.7 CFM per unit.
• Habitable room ventilation checked against IRC R303.1.
• Gas piping for a furnace, stove and water heater, 215 MBH per unit over about 130 ft.
• Water supply and sanitary drainage on every level, sized with Illinois Plumbing Code fixture units.

Each townhouse has its own gas meter and about 130 ft of pipe to the farthest appliance. The piping carries the full 215 MBH from the meter at 1-1/4 inch, then steps down for the furnace, stove and water heater.

• IMC 2021
• IRC
• Illinois Plumbing Code
• IFGC