ᐅ Plastic Window Well – Should the Insulation Be Revisited?

Hello,
our basement window wells were screwed onto the 12cm (5 inches) perimeter insulation. From the inside, you can clearly see (see photos) the polystyrene and the textured surface of the basement insulation.

Should this be left as is, or has anyone had experience with sealing slurry, for example? Or maybe plastered differently?

Thank you for your feedback and suggestions.

It looks "wrong" to me. For our light wells, there was an additional insulation collar included that provides insulation all around the window and allows for the connection to the light well. I can look for photos later.

Hello,
thank you for the feedback. We were told that such an insulation extension is only required for a fully insulated basement; therefore, the window frames (MEA) are not insulated and also not sealed that thoroughly.
But has anyone ever applied sealing slurry on polystyrene? Is that possible?

To me, this still doesn’t look right. Either it’s insulated, and then it should be done properly, or it’s without insulation directly on the wall. I don’t think this is a fastening method approved by the manufacturer.
If you spread something on it, you have legally accepted it for sure.
For treatment, the critical point is the transition to the plastic. What use is sealing compound on the (airtight) polystyrene if the edges crack...

Hello,
according to an appointed expert, installing the basement window wells directly on the insulation is acceptable. The only issue is the poorly cut edges, which are a visual flaw. Special shaped parts could have been used to achieve a cleaner finish, or the insulation could have been trimmed with a hot wire instead of a saw. Since the basement windows are quite large, these uneven connections are visible, but technically everything is fine. We plan to improve the appearance of this flaw by repainting during a longer dry period.
Greetings from Saarland,

You used expanded polystyrene (EPS) instead of extruded polystyrene (XPS) for the perimeter insulation on the basement? Is that really compressive resistant?

According to MEA, you have to use the insulation frame when insulating; otherwise, the insulation is screwed directly onto the concrete. Anything else then at least no longer has approval.

Unfortunately, we do not have these insulation frames despite full insulation – but I can’t change that anymore.