Good luck whatever you choose. 

It depends on how much liquidity you have and how quickly you want to build up your portfolio.

Volkswagen Scout Brand investing $11M in Detroit, 200 new jobshttps://www.teslarati.com/volkswagen-scout-11-million-detroit-investment/Hotel Added to Hudson Site, total over $1.4Bhttps://www.detroitnews.com/story/business/2023/11/02/hudsons-site-hotel-plans-move-ahead-as-city-issues-permit/71426631007/Detroit west side Dexter Neighborhood Receives $21.5Mhttps://www.clickondetroit.com/news/local/2023/11/01/neighborhood-on-detroits-west-side-receives-more-than-215m-in-investments/Norway’s Nel Hydron investing $400M, 517 new jobshttps://businessfacilities.com/nel-hydrogen-will-build-400m-gigafactory-in-southeast-michigan#:~:text=In%20Southeast%20Michigan-,Nel%20Hydrogen%20Will%20Build%20%24400M%20Gigafactory%20In%20Southeast%20Michigan,green%20hydrogen%20using%20electrolyzer%20technology.Chase invests $200M in Detroithttps://www.axios.com/2023/09/28/detroit-rebound-jp-morgan-investmentGilbert Foundation invests $439M in Detroithttps://www.henryfordmsu.org/news/september-2023/gilbert-family-foundation-announces-nick-gilbert-neurofibromatosis-research-instituteBollinger Motors investing $44M, 237 new jobshttps://michauto.org/bollinger-motors-plans-44m-metro-detroit-investment/New Detroit Developments to Be Excited Abouthttps://www.metrotimes.com/detroit/15-new-detroit-developments-to-be-excited-about-photos/Slideshow/32734721/32735392BorgWarner Investing $20.6M, 186 new jobshttps://www.crainsdetroit.com/auto-suppliers/borgwarner-invest-206-million-create-186-jobs3 International Companies Choose Detroithttps://www.detroitregionalpartnership.com/international-investment-comes-to-detroit-region/District Detroit $1.5B Development, 12,000 temp jobs, 6,000 new jobshttps://www.detroitnews.com/story/business/2022/11/15/district-detroit-1-5b-development-to-include-housing-retail-hotels/69649853007/6 New Residential Developments in Detroithttps://detroitisit.com/6-new-residential-developments-in-detroit-to-know-about/$2.5B New Center by Henry Ford Health, Pistons owner and Michigan State Universityhttps://www.clickondetroit.com/news/local/2023/02/08/incredible-investment-in-our-city-25b-detroit-neighborhood-redevelopment-to-begin-in-2024/$300M Huntington Place Renovations & New Detroit Hotel https://www.crainsdetroit.com/real-estate/huntington-place-renovations-new-hotel-deal-reached

(UNLESS OWNER OCCUPIED OR CAPITAL IMPROVEMENTS)If the land lord supplies heat, rent increase shall not exceed 4% otherwise don't exceed 3%.tenants 65 or older 2%new tenants increase can not exceed 5% over the last tenant's registered rentyou must provide a new tenant the previous rent amount in writing.you must apply to the city for each increase with 60 days notice, depending on the US department of housing and urban development for a unit of similar size.fines will be levied on a daily basis if in violation. 

It often depends on the definition of the zoning classifications within each city; based on the below info, I'm not sure which zoning classification a duplex would fall into.

Depending on where you buy, you might even get new homes with no value add, that you can buy and hold. 

The answer to this depends on the local market.

Penalties:Misdemeanor of the first degree: This can result in a maximum imprisonment of one year and a fine of up to $1,000.Civil penalties: You may also face additional civil penalties depending on the specific circumstances.Permitting issues: Local permitting authorities might withhold final approval, revoke the permit, or pursue other actions against you, maybe not give you the CO. 

Also would depend on foreclosure costs and time lines.

Lending - depends on if you are lending your funds or you are brokering the deal out.