Instead of wasting your money you might want to print out the harmful effect of not replacing the filter for residents and make sure the tenants always get a copy and warning,     Also you can take it a step further and you can-write it in the lease that "if the filters are not replaced regularly tenant understand that this will cause a $300 repair bill at the end of tenancy, where tech or HVAC cleaning co. needs to come out and clean the system."

I have an out dated porch in need of repair that I wanted to replace before the appraisal, cost of materials has really slowed progress.

I'm keen to refinance and build a 3rd smaller rental suite under the existing house as it's on a hill and there's a small workshop space with some rock retaining wall that needs to be replaced with concrete foundation anyway.

Mrinal,First, the umbrella does not replace the need for the the Liability on the underlying properties. 

Let's assume you have to replace floors every 10 years.

Are you looking to replace your job income?

I believe that the door really needs to be replaced, and the tenant is saying that it is not caused by them and that it was already like that when they moved in.

I dont want to have to replace the tub or the tile surround for while.

The high-end "executive" rental is in high demand here right now with tons of people moving here who are looking to buy property who need to rent until they find something, people who sold their homes and aren't able to find a replacement property, nomadic tech-workers working remotely/on contract assignments with google, microsoft, etc. 

It would be better to replace the plywood and the floor joints but thats a lot to.