No Air Tightness On Window 1x1 Side, and Window 1x2 Side (L+R)
Won't Fix
Version: 1.209.022 b1 default
BuildID: 23126650
Date of observation 10/05/2026
Recreated in Creative mode
Grid Size: Large + Small
Video: https://www.youtube.com/watch?v=sOlXz7DLN3c
Hello
It is my opinion that the following window blocks are bugged.
Large Grid+Small Grid
Window 1x1 Side
Window 1x1 Side Inv
Window 1x2 Side Left
Window 1x2 Side Left Inv
Window 1x2 Side Right
Window 1x2 Side Right Inv
The issue I am seeing, regards them not being air tight.
I have created a test grid and run the leak finder feature of a hud mod to show the issue in the video linked at the top of this report.
I will also attach the blueprint of this test grid.
Cakes
Files:
window side bug...
I have the same bug
Hello Engineer,
Thank you for the report and for the provided video.
We checked this case with our design team. The current airtightness behavior of these side window blocks is intentional and is caused by how the airtightness system works.
In short, airtightness is performance-heavy, so the system uses simplified checks. Because of this, only full 1x1 block surfaces can be reliably treated as airtight. Half surfaces or more complex window shapes may look visually closed, but the system can still treat them as non-airtight.
Changing this behavior could create other issues, unexpected behavior, or possible exploits with air pressure setups.
Because of that, we will treat this as intended behavior / a known limitation rather than a bug.
Thank you for your understanding and for taking the time to report it.
Shcherbinin Dmitrii,
QA Team
Hello Engineer,
Thank you for the report and for the provided video.
We checked this case with our design team. The current airtightness behavior of these side window blocks is intentional and is caused by how the airtightness system works.
In short, airtightness is performance-heavy, so the system uses simplified checks. Because of this, only full 1x1 block surfaces can be reliably treated as airtight. Half surfaces or more complex window shapes may look visually closed, but the system can still treat them as non-airtight.
Changing this behavior could create other issues, unexpected behavior, or possible exploits with air pressure setups.
Because of that, we will treat this as intended behavior / a known limitation rather than a bug.
Thank you for your understanding and for taking the time to report it.
Shcherbinin Dmitrii,
QA Team
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