Most do not even know what it costs to replace a hot water heater on a weekend.So your rule is a way too aggressive derivative of the 1% rule. 

@Brock Barr  I think there's a large segment of the investor population that derives physical pleasure from analyzing properties but then will suffer physical and emotional torment when it comes to actually doing something.

The overwhelming number of real estate investors don't have the faintest idea how an appraiser will derive their opinion of value.  

In the derivative market regular investors buying calls while the bank is selling the premium and keep hedging.

Robert Kiyosaki illustrates it best when he said "currency is derived from current, as in moving water.

Don't use % for capex and maintenance, these costs are derived from fundamentals and tenant base.

The bottom line is that disqualified persons are not allowed to derive any immediate benefit from the account, meaning, for example, they cannot live in or use real estate owned by the IRA.Here are a few other IRA facts that frequently come into play and that should be considered when choosing assets while protecting the tax-advantaged status of an SDIRA:Physical precious metals in an IRA may not be held directly by the IRA holder.An IRA can loan money out with or without collateral attached to the note.An IRA can purchase an interest in a private company expressed as shares of stock or equity ownership.An IRA holder may not perform sweat equity on a real estate asset.An IRA holder may not receive compensation from an IRA-owned asset.An IRA can secure a loan to purchase a real estate asset but it must be “non-recourse” to the IRA holder or other disqualified person.Unrelated business income tax (UBIT) may apply to IRAs that own leveraged real estate or an ongoing, revenue-producing business.An IRA can pay vendors (from lawn care to legal work to insurance coverage) to service assets in the account.An IRA can purchase assets with partners (people, even family members; companies; other IRAs; etc.).

Instead, they are carried forward (or backward) to other taxable years to offset other income sources derived from the same business. 

Back story-I’ve been trading derivatives for about a decade now and I’ve always been interested in RE since Rich Dad Poor Dad.

Once the height is determined you will be able to establish if it is possible to build above the most recent flood plane elevation based on calculations derived from the most recent “10 year flood plane map”.