The streaks on the concrete you see are from the water coolant on the concrete saw which gets cleaned off before landscaping
Proper buck frame in new window cut opening
We did not use treated lumber here to prevent the common occurance of treated lumber in contact with aluminum trim coil rot. We sealed the lumber fully with sealant to the brick to prevent any moisture transfer. After with window installation we fully sealed the opening again with low expansion window foam to complete the thermal envelope. For the first point of contact for air infiltration and water management we sealed the aluminum coil to the brick, then to the window for a full seal in a face barrier application.