Kitchen Plumbing Plan

Kitchen Plumbing Plan

The kitchen plumbing system supplies cold and optional hot water to the kitchen sink and routes grey water to the dedicated internal kitchen grey tank.
This plan outlines the functional purpose, routing strategy, installation considerations, and system integration for the kitchen plumbing layout.
It works in tandem with the Kitchen Plumbing Diagram and the Plumbing Master Plan.

Purpose of the Kitchen Plumbing System

The kitchen plumbing is designed to support daily cooking, cleaning, and food preparation needs while maintaining a simple, reliable, and serviceable layout.
The system includes:

  • Cold water supply from the bathroom manifold
  • Optional hot water supply from the hot water heater in the garage
  • Sink drain routed to the internal kitchen grey tank
  • Vent path for the grey tank (if required)
  • Protected routing through interior cavities

System Components

  • Kitchen Sink: Primary fixture for washing dishes, food prep, and general use.
  • Cold Water Line: PEX line routed from the bathroom cold water manifold.
  • Optional Hot Water Line: PEX line routed from the hot water heater manifold in the garage.
  • Sink Drain Assembly: Standard drain with P‑trap leading to the grey tank.
  • Internal Kitchen Grey Tank: Dedicated tank for kitchen wastewater.
  • Optional Grey Tank Vent: Prevents vacuum lock and improves drainage performance.
  • Shutoff Valves: Installed under the sink for service and winterization.

Kitchen Plumbing Layout (ASCII)

The diagram below shows the routing from the bathroom manifold to the kitchen sink, and from the sink drain to the internal grey tank. 

Interior - Bathroom Area
┌───────────────────────────────────────────────┐
│   ┌───────────────────────┐                  │
│   │ Cold Water Manifold   │───┐              │
│   └───────────────────────┘   │              │
│                                │ PEX Line     │
│   ┌───────────────────────┐   │              │
│   │ Hot Water Manifold    │───┘ (optional)   │
│   └───────────────────────┘                  │
└───────────────────────────────────────────────┘
             │
             │ Routed through protected chase
             ▼
Kitchen Area - Front Wall
┌───────────────────────────────────────────────┐
│                                               │
│   ┌───────────────────────────────┐           │
│   │        Kitchen Sink           │           │
│   └──────────────┬────────────────┘           │
│                  │ Drain                        │
│                  ▼                              │
│        ┌───────────────────────────┐            │
│        │  Internal Kitchen Grey    │            │
│        │          Tank             │            │
│        └───────────────────────────┘            │
│                                               │
└───────────────────────────────────────────────┘

Routing Strategy

The kitchen plumbing routing is designed for efficiency, freeze protection, and ease of service.

  • Interior routing: All supply lines run inside conditioned space.
  • Short, direct runs: Minimizes pressure loss and simplifies installation.
  • Drain slope: Ensures proper flow into the grey tank.
  • Grey tank placement: Positioned for easy access and maintenance.
  • Optional venting: Improves drainage and prevents gurgling.
  • Under‑sink shutoff valves: Allow isolation of the kitchen for service or winterization.

Installation Notes

These guidelines ensure a clean, safe, and durable installation.

  • PEX Routing: Use clamps or brackets to secure lines and prevent vibration.
  • Hot Water Line (optional): Routed alongside the cold line for symmetry and ease of service.
  • Drain Assembly: Use a standard P‑trap with easy access for cleaning.
  • Grey Tank Connection: Ensure a watertight seal at the tank inlet.
  • Vent Line (optional): Route upward to prevent siphoning.
  • Leak Testing: Pressure‑test supply lines and fill the grey tank to check for leaks.

Integration With the Plumbing System

The kitchen plumbing integrates with the larger plumbing system as follows:

  • Cold Water: Bathroom manifold → Kitchen supply line → Sink
  • Hot Water (optional): Heater → Hot water manifold → Kitchen supply line → Sink
  • Grey Water: Sink drain → Internal kitchen grey tank
  • Toilet: No connection to kitchen plumbing

Related Pages

How This Plan Will Evolve

As the build progresses, this page will be updated with final component selections, exact routing paths, installation photos, and any additional kitchen plumbing features such as filtration systems, under‑sink accessories, or upgraded grey tank hardware.