And this low demand could be a couple of factors, either a rural location with low population density or the area incomes are not high enough in order to prevent a rent burdened scenario. 

@Pat Aboukhaled I would ULS (unit lot segment) the primary house and include a clause in the call option that would prevent them acquiring the DADU.

Meet other investors in your area and stay in touch with them; you can ask them questions that might prevent problems.Best to you!

Next steps are to put down a roll of plastic to prevent moisture or wet floors. 

But then we have to get into talking about the passive loss rules, which may prevent you from actually being able to claim a tax loss if the deduction is more than your rental or other passive income.Or you can claim the actual expenses (gas, insurance, etc) for the vehicle and regular depreciation, proportioned by the percent of business use of the vehicle.  

Naturally your property must sell before you can take title to the new one, but nothing prevents you from getting it under contract and make the process as smooth as possible.  

Keeping everyone aligned—lenders, inspectors, attorneys—prevents bottlenecks that could derail the timeline.Lastly, tackling big tasks early (like ordering inspections or raising equity) is a game-changer.

Buying in a quality area and being thorough with your tenant screening are the best preventative measures you can take to avoid that situation from arising.

It can be a normal problem but you can prevent it with some certain measures.

The rules are designed to prevent related parties from engaging in exchanges that shift high basis property for low basis property, followed by a sale of the low basis property, effectively "cashing out" without recognizing gain.If you sell a property to a related party as part of a 1031 exchange, both you and the related party must hold the exchanged properties for at least two years following the exchange.