This is a corner for the concrete-insulation system which places more concrete on the inside of the insulation, this becomes thermal-mass to regulate comfort-zone and is engineered for each room before the pour.
Combustion Appliance Zone Testing (CAZ) Made Easy (March 24, 2016)
-Adapting to the new BPI standard
-RESNET testing requirements
-NFPA testing requirements
-Best practices for best results