The floors are wet and bowing from the absorption of urine.

I am currently in the knowledge absorption/learning phase of REI!

No matter what the economic indicators tell you there is always a chance for the economy to slow down and appreciation to be significantly lower than what you expected.Personally I view it like this, If you are trying to see if the economy is going to appreciate you want to look at the economic indicators such as Colliers Report or vacancy and absorption reports; However you should always expect that even if you did all your homework correctly there may still be an economic downturn from an unexpected factor.  

It has to do with net absorption and vacancy rates.

Based on the amount of ponding and the age of the system, the inspector recommends replacement of the absorption system.

If you go and register at CBRE, they have a huge research arm with free reports you can download that give you very detailed data on the apartment building markets - absorption rates, avg rents, avg $/unit for sales...etc...  

Some brokers or brokerages also release periodic/quarterly market research for different markets in the US (and internationally) with research on market rates, vacancies, construction, absorption, etc.

Know your market, know the market rents and be aware of the absorption rates in your area or target area.

That's roughly 20 per month, which means that the absorption rate below $600k is 2 months.

All the while, construction of new Multifamily is at a multi-year low while absorption is high.