What MEP Design Does a Laundromat Require?

Laundromat MEP design is the engineering of mechanical, electrical, plumbing, and gas systems for a self-service laundry: high-capacity water supply and sanitary drainage for the washer count, dryer exhaust and make-up air per the mechanical code, water heating, and gas or electrical service sized for the dryer lineup. The drawings document code-compliant utility sizing, venting, and equipment connections for permit. Everything flows from the equipment schedule — the number, type, and utility requirements of every washer and dryer. That schedule drives the water service size, the sanitary main size, the gas service or electrical service size, the exhaust duct design, and the make-up air units. Designing before the equipment is selected is guessing, so I lock the equipment list first.

Water demand in a laundromat is spiky and large — many washers filling simultaneously. The water service, distribution piping, and water heating all get sized for that peak, not for an average. Drainage is equally demanding: washer discharge is high-volume and lint-laden, so the sanitary system needs proper sizing, cleanouts, and lint interception before the building drain. Some jurisdictions have specific requirements for commercial laundry discharge. The floor itself is part of the plumbing design. Trench drains or floor drains handle the inevitable water on the floor, and the slab gets sloped to drain. Waterproofing and floor finish selections matter in a space that's wet by nature. I coordinate the plumbing rough-in with the equipment layout down to the inch, because a washer drain six inches from its stub-out is a problem nobody wants to solve with a jackhammer.

Dryer exhaust is the mechanical centerpiece. Each dryer needs its duct run sized per the manufacturer's limits and the mechanical code — too long or too many elbows and the dryer can't move air, which means longer dry times and unhappy customers. Ducts route to the exterior, get cleaned-out access, and stay clear of intakes and property lines. Gas dryers add combustion air and venting requirements on top. Make-up air replaces what the dryers exhaust — often thousands of cubic feet per minute in a large store. I design dedicated make-up air units, sometimes tempered, so the building stays neutral and the dryers perform. Energy code compliance covers the building envelope, lighting, and any conditioned HVAC; in California the project documents to the 2025 California Energy Code (2025 Standards), effective January 1, 2026. The permit set shows utilities, venting, and equipment connections fully engineered.

• Equipment-first design: the washer/dryer schedule drives every utility size
• Plumbing: peak-demand water service, lint-tolerant drainage, and floor drainage
• Dryer exhaust: code-compliant duct sizing and routing for every machine
• Make-up air: dedicated units replacing the full exhaust volume
• Gas or electric: utility service engineered for the owner's dryer selection