@Brian Mendez although the local politics are concerning I don't see a massive devaluation of Seattle Real Estate as likely. 

And for those who are in their 30s and think they will retire with paid off rentals, don't forget to factor in the following:Maintenance, taxes and insuranceDepreciation for your heirs to repayUsually good appreciation at first and then slowing in later years,,,why followsEconomic devaluation due to properties maturingChanges in demographics of the community, hot areas don't stay hotCompetition of comparable units and and newer unitsDecline due to obsolesence, may not command rising rents foreverMaintenance issues deferred become rehab projects years laterTax benefits die outGovernmental regulations adopted may cause additional expensesVariable costs increase- with stagnet rents (ie, taxes and insurance)Property becomes inefficient and functionally obsolesent in the market.Buying a 15 year old SFD when you are 30 and keeping it till you are 65 gives you a 50 year old property......now go into neighborhoods with 50 year old properties and see what the market is like inthose older areas.......I suggest you buy, do a 1031 or sell and upgrade your inventories.

Most of the pension funds that you speak of have lost millions of dollars in devalued real estate, just like the rest of the country.

In California there is a full disclosure law, any huge issue known to the seller that devalues a property in anyway is declared in the purchase agreement.  

If you want to get more specific you can do the following:  OpEx NOI Replacements/CAPX NOI after RR Debt Service Cash FlowIf you put the cap x before NOI you just devalued your asset by $180,000 at a 5.75% cap.

Bitcoin we'll see, but if currency devaluation, manipulation, and/or anything in between is a growing issue then it's value should be material. 

When a investor does not maintain rent at market or allows maintenance to hold rents down they are devaluing their investment.

No devaluation in this market, we are in a sellers market regardless of how the lawn looks.  

A proper way to 'devalue' something due to damage so repairing/replacing is not required?

If you take something up front, then it immediately devalues the investment.