In addition, in response to public concerns about the quality of affordable housing, the Urban Construction and Environmental Protection Committee of the Municipal People's Congress recommended that the government make the quality of building materials for affordable housing the top priority of supervision and adopt stricter measures to ensure project quality.

　　Ma Shuguang, deputy director of the Urban Construction and Environmental Protection Committee of the Beijing Municipal People's Congress, said that because affordable housing is subject to government price caps, construction contractors have lower profits, increasing the risk of sacrificing project quality to boost profit margins, and making illegal practices such as cutting corners and substituting inferior materials more likely. At present, the city's building materials mainly rely on supplies from other provinces and municipalities; more than 90% of structural materials such as steel rebar come from other provinces and municipalities, and although concrete is mainly supplied locally, more than 90% of the raw materials for producing concrete also come from other provinces and municipalities. The building materials circulation market has wide marketing channels and many levels. This situation has brought great difficulties to supervision over the production and circulation of building materials, and the supervision results are not ideal. Therefore, the relevant administrative departments of the municipal government must strictly control the final quality gate at the stage of building material use, strictly implement systems such as building material procurement filing, on-site retesting, and witnessed sampling and submission for inspection, and ensure that construction enterprises use building materials reasonably in accordance with design requirements and operating standards.