Spending the owner's money, not saying anything, and letting them discover it while reviewing the monthly statement is unprofessional.

Good people gave me work, I learned more skill, more money, worked hard!

This risk is amplified the less money you have attached to the deal.

The expert you are looking for is called a Land Surveyor, they're going to want 5k-15k, if you want to make any money on your project you need to build a house so you also need an architect, they will want 10k-50k, if you're in a hillside zone you will also need a geologist, they're going to want 10k, you will also need a biologist, they're going to want 2k-5k.

But now I'm thinking of renting the whole house and getting a cheap apartment to save even more money.

They are worth the money for a good hot tub that is mentioned all the time in reviews and doesn't have a ton of issues.

@Malcolm Brown it is great that you are thinking of the money to fund the deals you are going to get started with but understanding what a deal is, I think, should be the starting point. 

You’ll get a better return over the long-term by putting your money in the stock market.

We often use zoom showings, but they build on that mutual in-person experience.We don't encourage bottom-of-the-barrel neighborhoods, simply because with 60-120 year old properties capex tends to exceeed cash flow over time aka money pit.

Sometimes occupants still live there and eviction is not easy, and I have even heard a story once that the yakuza are involved in the construction and real estate business and exorted money from buyers through occupants in these properties.