1. Foundation and main structure works, that is, the reasonable service life of the works specified in the design documents;
2. Roof waterproofing works, leakage prevention for bathrooms, rooms and external walls with waterproof requirements, 5 years;
3. The heating and cooling system has two heating periods or cooling periods;
4. Electrical system, water supply and drainage pipeline and equipment installation for 2 years;
5. The renovation project lasts for 2 years.