@Alice Huang I had a situation with sidewalks where the old owner was notified sidewalk repair was required and failed to do it.

If you have a single family house, the tenants are responsible for cutting the grass, shoveling the sidewalks, etc. 

Snowplow service to clear the driveways and sidewalks and porch is one thing that comes to mind. 

Snow removal is on my tenants to take care of, if town issues a fine for side walks being covered bill goes to tenants.  

Hopefully they can access the defect from inside the basement, which will save a lot of money, but they might need to dig up the sidewalk. 

I'm not sure what local people charge to shovel roughly 20Ft of sidewalk and 6 stairs leading up to the front door.

.- Biggest one was add handrail along retaining wall next to driveway, since there was also a sidewalk next to retaining wall and drop was over 30".  

Some areas of Oklahoma and Texas have such unstable soil that foundations and driveways and sidewalks are a constant source of frustration. 

I finished both the state and federal parts in 30 minutes.  10 minutes later, I was on the sidewalk with a real estate license in my hand.My advice is to get your license and operate within the law instead of working in the shadows.

How to know how much land we need to keep it for sidewalks?.