I just went to the house for three months. How to sue if the guardrail is lost?

You can sue. If it is a quality problem, you can ask for maintenance or compensation 1. If it is a residential commercial house, you can talk to the property management first and let the property come forward to find the original contractor. Balcony guardrail shall be provided by the contractor to the guardrail manufacturer. If it is still within the warranty period of the contract, it can be repaired and replaced free of charge. 2. If the private balcony guardrail is broken, you can go to the local building materials market or hardware processing shop and find professional guardrail maintenance and installation personnel to repair or replace it. 3. If only a few vertical rods are rusted or broken, only the broken ones can be replaced, so the price is much cheaper. If the balcony railings are corroded or damaged in a large area, it is best to replace them all, mainly from the perspective of safety, especially in high-rise residential buildings. Of course, it costs a lot of money to replace them all. Summary: The balcony guardrail is broken and rusted. If it can be replaced, try to replace it with a new one. After all, safety comes first.