I've done almost every type of real estate from construction, land, multi-unit, small hotel, raising capital for off shore to traditional and most common; single family investment property.

CA FTB is pretty clear that presence in CA other than temporary in nature constitutes residency.

A lot of areas like the jersey shore are built around the summer season when everyone shows up.

@Mickey Yang  - I think you are talking about a property here in OKC - if so, I've recently replaced one (last fall/2022); and it was one that one plumber initially told me we be more expensive b/c it was deeper than six feet -so  they would need to shore up the sides/per OSHA regulations. 

2.4.8 - Single-family Residential 6 (R-6).In a R-6 single-family district no land shall be used and no building shall be erected for or converted to any use other than:a)Principal uses: The following uses shall be permitted as principal uses:1) Single-family detached dwellings.2) Public and non-profit institutions of an educational, religious or cultural type excluding corrective institutions and hospitals.3) Governmental buildings and uses.4) Public utility uses required to service the district.5) Public and private noncommercial recreational areas and facilities such as public parks, country clubs and golf courses, excluding miniature golf courses and driving ranges.6) Temporary buildings when they are to be used only for construction purposes or as a field office within a subdivision approved by the city for the sale of the real estate of that subdivision only.

If they are paying $3,000 a month in rent, surely they can afford that temporary inconvenience.

It's better instead to realize there are two tax systems in the United States.One for the educated.And one for everyone else.There are very few actual tax loopholes, which are often remedied with technical corrections and temporary regulations.There are creative people, but if you know about it trust me it's not a loophole. 

The prior commitment can include a pretty aggressive rate buydown (something that would exceed the amount permitted with a more traditional lender credit for a temporary or permanent rate buydown. 

Outside of the city flipping is more prevalent, especially West Shore / Cumberland Valley School District, assuming you can even find anything. 

THD (Temporary Housing Directory, Inc) reached out to me working as a coordinator on behalf of them.