Materials provided are generally property certificates, lease agreements, project layout plans, waste oil and grease recycling agreements, drainage permits or proof of piping, and environmental certification qualifications for grease fume purifiers. You then compare the specific provisions of the catering industry in Beijing to see if there are any requirements for the height of the fume purifier discharge port, and the distance from the surrounding residents. I'm not from Beijing, so I can only answer so much, I hope to help you! Oh