Subdivide and create free lot

[Rudy Manna]

I have been doing buy and hold deals so far. Now I feel like taking the plunge and take it to the next level. My plan is to buy a house in a large lot, subdivide and create a free lot. Put the house for rent and go for new construction in the free lot. Experts such as  @Ryland Taniguchi among others are implementing this strategy at scale. 

I need to do some research/studying so that I can evaluate feasibility before going for the deal. Can the experts give me some guidance around the following:

1. If I take bank loan to buy, will that cause any problem with applying for the subdivision? I guess I can refinance after the subdivision minus the plot, and hold the plot free and clear. Looking for some real experience.

2. Are there any zoning restrictions/requirements I should look for?

3. What would be the minimum lot size to be eligible for subdivision? Are there any formula or any such thing?

I am considering south side of Seattle such as Tacoma, Olympia, Puyallup etc.