Thick walls with more than enough thermal mass to easily handle the westerly sun without heating up.
We have a rammed earth wall 3 mtrs high and 9 mtrs long.
It is our saving grace wall, winter and summer and all part in between.
onc
May I ask if your west wall was rammed earth as well?
My colleague had a architect designed eco-house comprised of 50K worth of rammed earth walls. But they didn't use a radiant barrier on the west side and the sitting room behind it overheats in summer.