Legal basis: Article 18 of the Regulations of Beijing Municipality on the Quality of Construction Projects, the legal representatives of construction, survey, design, construction, supervision and other units shall sign a power of attorney to specify the person in charge of their respective construction projects. The person in charge of the project shall sign a commitment letter of lifelong responsibility for project quality. The legal representative and the person in charge of the project shall be directly responsible for the construction quality of the corresponding project within the design life of the project.