No, he's not an architect, he drew all designs, floor plan, site plan, etc, and we had a structural engineer design his part, and paid an architect to sign off on them.  

However, after receiving the survey results, I discovered that the house is located less than 1 foot over the sublot line (see attached image).Here are the options I’m considering:Rent the current house for market value (~$1,500–1,600/month) and convert the detached garage into an ADU to rent for ~$1,000/month.Relocate the house to split the lot, then sell the newly created lot (~$100,000) while renting out the existing house.Relocate the house to split the lot and build a new home on the second lot.Demolish the current house and garage, split the lot, and build two new homes.At this time, I am uncertain about the cost of relocating the house.Questions for the community:Has anyone faced a similar situation?

If so maybe it's time to sell and reallocate.  

However, if I take my resources and spread it around, I can weather bad times better.

I would restate that the lease will remain in place until such time that a new tenant is selected and moves into the property.This approach will ensure your cash flow while acknowledging that 'stuff happens.' 

If the opposing part comes back with a different” number(s) or terms, I politely reject it and reiterate my initial and only offer.  

Rents generally rise over time, and while mortgage rates are high now, they won’t necessarily stay there forever.

STRs have a huge earning potential but it's definitely something that takes a lot of time, patience, and effort these days.

They have been around a very long time.

Additionally, most of the costs to make an asset ready for it's intended business use are capitalized and part of the cost of the asset.