By the time a kitchen plan lands on our desk at Northbay Restaurant Design, there’s a good chance it’s already been through a first pass by a contractor, an owner’s own research, or a generic template pulled from somewhere online. And with remarkable consistency, the warewashing section of that plan contains at least one of five specific mistakes. Here they are — and what actually needs to change to fix them.
We see this constantly: a dishwasher selected because it “fits the space allotted” rather than because it matches the restaurant’s actual projected covers, menu complexity, and ticket volume. A compact undercounter unit crammed into a full-service kitchen designed for 150 covers a night creates exactly the dish pit bottleneck we’ve described in our warewashing labor guide — one that shows up on your first busy Friday, not during initial planning.
The Fix: We size dishwasher capacity based on projected volume, menu-driven dish and utensil turnover, and peak service demand — not simply the square footage available in the layout. Sometimes this means reconfiguring the layout to accommodate the correctly sized unit, rather than shrinking the unit to fit a predetermined footprint.
This is one of the most common compliance gaps we catch. As we’ve covered in our dishwasher compliance guide, California requires a functional three-compartment sink for manual warewashing even when a commercial dishwasher is installed — it’s a standalone requirement, not an alternative to mechanical dishwashing. Plans that omit this, assuming the dishwasher alone satisfies the requirement, generate an immediate and predictable plan check correction.
The Fix: We build a properly sized three-compartment sink into every warewashing zone design from the start, positioned logically alongside the dishwasher rather than as an awkward afterthought squeezed in after a correction letter arrives.
Commercial dishwashers, particularly high-temperature units, produce significant steam and heat — and plans frequently place them without accounting for the ventilation this generates. As we’ve noted elsewhere, this can require a Type 2 exhaust hood over the dishwasher depending on your specific unit and kitchen configuration, a requirement that’s easy to miss if the dishwasher is treated as an isolated equipment selection rather than part of the overall mechanical design.
The Fix: We evaluate ventilation needs for your specific dishwasher type and capacity as part of the same mechanical coordination we apply to your cooking line hood system — not as a separate, disconnected consideration addressed only if a reviewer flags it.
We frequently see plans where the three-compartment sink is positioned near the dishwasher, but no separate, dedicated handwashing sink is placed nearby — sometimes because of an assumption that staff can use a handwashing sink elsewhere in the kitchen when needed. CalCode requires a dedicated handwashing station conveniently located within each food handling and preparation area, and a warewashing zone genuinely qualifies as an area requiring its own accessible handwashing sink, separate from your prep and cooking line handwashing stations.
The Fix: We include a properly positioned, dedicated handwashing sink within every warewashing zone design, distinct from the three-compartment sink and from handwashing stations elsewhere in the kitchen.
As we’ve discussed in our labor-focused dishwasher guide, the choice between high-temperature and low-temperature sanitizing carries real operational implications — booster heater requirements and higher energy use for high-temp systems, versus ongoing chemical sanitizer monitoring and documentation obligations for low-temp systems. Plans frequently default to whichever type a vendor happened to recommend, without evaluating whether it actually fits the kitchen’s utility infrastructure or the staffing model available to manage ongoing compliance requirements.
The Fix: We evaluate this decision against your actual utility capacity — including whether your gas or electrical infrastructure can support a booster heater, as we’ve discussed in our infrastructure assessment guide — and your realistic staffing plan for ongoing sanitizer monitoring if you choose a low-temp system.
None of these errors happen because owners or contractors are careless — they happen because warewashing design sits at the intersection of plumbing, mechanical, health code, and labor planning, and very few people outside dedicated kitchen design experience are thinking about all four simultaneously when they’re focused on getting a dishwasher into the layout. This is exactly the kind of cross-disciplinary coordination that professional kitchen design is meant to catch before it becomes a correction letter or, worse, an operational problem discovered after opening.
These five dishwasher mistakes show up in nearly every kitchen plan we review for the first time — and every one of them is far cheaper to fix during design than after a correction letter or a failed inspection. Northbay Restaurant Design builds warewashing zones that avoid all five from the very first drawing.
Contact us today for a free consultation and let’s review your kitchen plan before your county’s health department does.
