if the original building structure and building wall are not changed, it belongs to interior decoration project, and a qualified interior design company is hired to carry out interior decoration design and a qualified fire protection design company to carry out fire protection design, which will be submitted to the fire station for approval before construction.

if the original building structure and building wall are changed. That belongs to the reconstruction project. According to the national regulations, the reconstruction project also needs to hire a qualified architectural design institute (preferably the original design unit of the house) to design, pass the drawing review, apply for a construction permit, and add the above indoor and fire protection design data to the fire station for approval before construction.

according to the requirements of the question, the above only said that the fire control project should be built, and the interior decoration project exceeding 311 square meters should be built according to the regulations.