Hi all, I have a quick question and would really appreciate some feedback/guidance.

I am currently working on a building that is entirely below ground in Saudi Arabia. We have data to suggest that the temperature will be a constant 27 degrees Celsius, once you’re about 4m deep. I am tasked with identifying if they need insulation and I am using energy modeling to predict it’s estimated energy consumption.

What I am a bit confused about is, if I am setting the exterior wall temperature 27degrees, do I still account for the ground resistance and the walls? - doing so would obviously improve the u-values of the walls, and provide further protection from the 27 degrees, but that makes no sense to me, since the ground itself is already 27 degrees. So logically to me, the ground resistance should not be providing any benefit/protection from the 27 degrees, since the ground is already is already 27degrees.

Or am I thinking about this all wrong?

Should I just account for the ground resistance, and ignore below ground temperatures?

Obviously if I treat the walls like regular walls and not account for the ground resistance, the results show that there is a need for insulation. And similarly, if I account for the ground resistance, obviously that U-value is significantly improved, and therefore there is no need for insulation.

I know that in the region they typically don’t insulate below ground structures, I don’t really understand why. I spoke to multiple engineers about this and I am getting mixed answers, with no logical explanation.

Would love some feedback and thoughts on the matter.

Thanks in advance,

Mony