Building construction
True to its name, this fixed-dome is a dome made of brick and concrete but buried underground, designed to be planted below ground level to avoid possible physical damage and save space.

There are six parts of the BIRU reactor, namely:

The construction of a  fixed-dome reactor requires experts to be able to maintain the quality of the reactor. These experts are members of the CPO (Construction Partner Organization). Apart from being responsible for building, CPO is responsible for maintaining the quality of the reactor. The entire concrete dome reactor building refers to SNI 7927: 2013.

With regular care and use, the fixed-dome can last up to 25 years. Apart from its long duration, the fixed-dome also lacks maintenance. To operate the fixed-dome, a minimum of two cows or seven pigs or 170 chickens is required. This figure is needed to meet the needs of the primary raw material for biogas, namely livestock manure.