|If you mean the interior corners are cold during heating season when the conditioned space is heated and its cold outside, this is a common occurrence. Several factors contribute:
1. Air does not circulate well into corners, so corners are difficult to heat.
2. Building practices have difficulty insulating corners to the extent of other portions due to the large amount of structural building material required to make a good corner. Such material (eg wood) doesn't have the same insulating properties as an insulated wall cavity.