The width of the dome determines your cooking space and the height of the dome is always 3/4th of the width. The main job of the dome is to hold the heat. The heat energy goes into the dome evenly and then it is radiated back and used for cooking after the heat source is removed. It is always better to construct a brick dome instead of a prefabricated dome because prefabricated domes develop cracks and start peeling.
For best heating in your oven, it is important to be careful about the height of the dome and the door. The ideal heights are:
Entry door height: 10 inch (25.4cm) Vault height (internal): 16 inch (40.6cm)
The dome of a pizza oven can be constructed in a number of ways: