I recall presenting a preliminary design to a client, and after reviewing the entire plan, I only remember them having one question: "Where's the toilet [in the primary bath]?"

I was flushed with embarrassment.

There's more to this story, including how I redeemed myself and a plan review trend that's beginning to develop.

But first, today marks World Toilet Day.

"We'll always need the toilet."

"In a changing world, that is one thing that is constant," is the statement on the United Nations' webpage, the organization that founded World Toilet Day.

In architectural plans, the toilet may appear as a simple symbol or BIM object, easily selected and dropped onto a drawing. But this "component" represents much more than a plumbing fixture: it is fundamental infrastructure that directly affects health, equality, and resilience in the built environment.

World Toilet Day, and its 2025 theme, "Sanitation in a changing world," calls for accelerating action toward water and sanitation for all. It highlights the urgent need to invest in future-ready systems that adapt to aging infrastructure, climate change, and growing inequity.

Thoughtful placement and privacy in design empower vulnerable populations, especially women, girls, and people with disabilities.

A simple toilet can mean the difference between dignity and deprivation.

As a design professional, you have the power to shape spaces that respect and uplift every user. Each symbol placed in our designs is one step closer to the UN's vision of sanitation for all.

By reimagining 'the humble toilet' as both an object (in the CAD sense and physical sense) and an opportunity, we build healthier, more equitable communities, one green stencil trace at a time.

Speaking of stencils and sketching, it turns out my preliminary design included a place for the toilet; it's just that I forgot to drop the symbol in the drawing.

No need to panic, the plans were fully flushed out! I blamed the layering or the visible items list (shame on me).

Here's another thing World Toilet Day brings to my mind.

Building departments are increasingly requiring more detailed plumbing information on residential construction drawings. To standardize this process, the International Code Council (ICC) has published a checklist that plan reviewers are encouraged to use when permitting house plans.

While you may address some of the items with simple notations, a growing number of building departments now request isometric plumbing plans—specifically for waste lines—as a visual way to satisfy the more complex requirements.

I understand the desire for greater clarity in how drain, waste, and vent systems are designed and installed, which helps minimize misunderstandings and ensures code compliance before construction begins.

My preferred approach is to mandate that only an as-built drawing be submitted once the underground and rough plumbing installations are complete. I know of a couple of jurisdictions that require both the initial design and the final as-built documentation (almost to my liking).

Be that as it may, you may have already been asked to provide plumbing isometric diagrams as part of residential plan submissions, not just for large-scale projects or commercial work.

The isometric plan provides a standardized, three-dimensional schematic, aiding plan reviewers in verifying pipe sizing, slope, venting, clean outs, and fixture relationships to ensure that the proposed system complies with code.

It sounds daunting. Some mechanical engineers are excited as these new requirements begin to take hold across the country.

So far, the expertise of a mechanical engineer isn't required. As a residential building designer, you should be perfectly capable of producing this type of drawing, and plan reviewers routinely accept it.

One affordable option for clients might be the plumbing subcontractor. Some plumbers have caught on to the idea and are providing the necessary "shop drawings" included in the plumbing contract. I've seen some professionally done drawings, typically from companies that insist on being the ones to provide the plumbing plan. And I've seen some "drawn by hand on a tailgate" versions.

What I provide is somewhere in between.

To ensure everything flows smoothly, I've put together a brief tutorial with step-by-step instructions, helpful tips, IRC references, and example drawings.

​👉Let's go to the tutorial.

From drawing board to drain, make sure every fixture has reported for "doody" and you're not left holding the tank!