Exploring Isometric Drawings in Domestic Water Systems

Understanding Isometric Drawings in Residential Plumbing Design

Learn about the use of isometrics in architectural drawings, particularly in mapping out the layout of water and gas lines in a building. This article presents an accessible explanation of how isometrics are used to plan the installation of piping systems in a slab-on-grade house.

Key Insights

  • The article highlights isometrics as an integral part of architectural drawings, used to display buildings axonometrically. In this case, isometrics are utilized to demonstrate the layout of domestic water and gas lines in a slab-on-grade house.
  • The owner of the house decided not to bury the water lines under the concrete but to install them above the ceilings and make them drop down as needed. The isometric representation facilitates understanding of this unique setup, showing how the lines rise above the ceiling and drop to feed various utilities such as the dishwasher and the ice dispenser in the refrigerator.
  • Isometrics also assist in the visualization of how the gas line is installed. The article delineates the path of the gas line, entering the house, rising to the ceiling, branching over to the range, oven, forced air unit, water heater, and fireplace. Hence, isometrics prove to be explanatory in conveying the installer's plan to comply with the required layout.

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One thing that I think is especially fun in these drawings are the Isometrics. Isometrics are generally showing the building axonometrically. So what's going on here, here's the Domestic Water Isometric.

This house is a slab-on-grade house. And the owner decided that what they wanted to do was not to have the water lines buried under the concrete, but rather to come in above the ceilings and then drop down. So for example, here is my Dishwasher.

So I have a DW note right here for Dishwasher. Here is my Dishwasher here. So I essentially have the kitchen going on in this area.

Here's the Water Heater. The Water Heater here is located right over here on the left. So here's the Water Heater, and there's the Water Heater.

So what's going on is that this wall that's represented here is shown diagonally over here in the isometric. So I have my Dishwasher, and the lines are coming up, going above the ceiling, and then dropping down as needed. So for example, this is the feed for the Ice Dispenser in the refrigerator.

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So I can tell right here that the water is coming into the house at this point. So this is where it's coming into the house. Here's the Pressure Regulator.

It comes in, branches up, and goes over. I now have the lines that are going to be feeding into the Hot Water Heater. And so a Hot Water Heater line would go up and over and feed the rest of the house.

So again, this is the isometric for the domestic water. If I slide down, here is the isometric for the Gas Line. So here's the Gas Meter.

It's coming into the house, going up in the ceiling, branching over, and going down to the range. It's coming back up, down to the oven, the Forced Air Unit, the Water Heater, and there's also a gas feed for the Fireplace. So you can see the Isometrics are pretty explanatory as far as how the Installer will actually lay out the piping to conform with the requirements shown in the plan.

But then from an Isometric standpoint, we're saying this is how it needs to come in, go up, and go over.

photo of Al Whitley

Al Whitley

AutoCAD and Blueprint Reading Instructor

Al was the Founder and CEO of VDCI | cadteacher for over 20 years. Al passed away in August of 2020. Al’s vision was for the advancement and employment of aspiring young professionals in the Architecture, Engineering and Construction (AEC) industries.

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