Seems like a simple matter but this house has one continuous concrete beam underneath the exterior walls.

MANY factors involved; vegetation, slope of the ground, soil composition that may/may not absorb the water ... but those areas where it pools, or doesn't have those items listed prior, you may need gutters.

The refrigerator could not fit underneath the cupboards on the right at the purchase, so the refrigerator was in the attached dining room table area, leaving no place for a dining room table.

It is another to deal with the roller coaster of emotions that arise from tenant abuse.If you are going to make this a rental property be prepared to say good bye to all of the little details that make this house an emotional treasure trove.The tree that you planted as a child will soon have a tire swing hanging from it and the ground underneath will be barren.

But added expense are architectural design, Soil Engineering, but some communities have pre-approved ADU designs at no addittional cost to $500.00.

Land surveys and other studies - Geotech report, soil report, fault lines, environmental report etc.Most of the lots would not survive these due diligence items.

The team underneath them seemed less than stellar and I would definitely use a different lender. 

You should also get a soils report (or look for existing nearby soils reports the city would accept), as well as get a topographical survey of the property done. 

It’s got studs on 24”, weird siding material that is basically sawdust and glue that doesn’t hold paint and blows up and turns to mush if it gets wet, a cheap slab foundation combined with expansive soil that has cracked the foundation, the layout is 80’s split-level (outdated and hard to change), the windows are crap, the roof is crap, the insulation is crap, and the hvac was set up all wrong with no air returns on some of the levels, not enough registers and returns… it’s what they now call a “sick house” for that reason (poor indoor air quality due to badly designed ventilation system). 

(soils study, ect)