You've got potential delays for builders to do a site assessment for the buyer, potential delays in having a soil engineer available for a soil study, etc etc.

The property is not farmable as it’s mostly lava rock according to soils reports.

A French drain is like adding a coffee filter buried a foot below the top of the soil.

A mouse had died underneath the pantry. 

In bay area, I am paying about 25K for labor and about 10-15K for material for a 380 sf patio room conversion to a 1 bedroom, with raising the structure and installing a new 4" concrete pad underneath the existing patio structure.Permit fee and other design cost would be extra.

I built 3 homes in one zone in Portland and was NOT allowed off street parking or garage I wanted to go under neath the units for parking NOT ALLOWED  you know everyone should take public transit or ride their bikes. 

details on home:-SFR single-story,4bed 2 bath, 1962 built, SF Bay area, high end, prime location- bedrooms + living room is carpet  (hardwood underneath) - I can remove the carpet in the living room area and might refinish hardwood depends on condition.- popcorn ceiling in bedrooms + living room- kitchen white laminated countertop and cabinets, with oak trim- kitchen appliances all white except the microwave is stainless steelplans so far:> already planning to  add recessed light in the living room (and remove fan) (kitchen already have recessed lights), bedrooms have the fan> paint oak to white (kitchen cabinets, bathroom vanity )> kitchen countertop - granite or quartz?

Testing for asbestos is beyond the scope of this inspection.TESTING RECOMMENDED: This geographic area is known to have levels of radon in the soil that are above the EPA’s recommended actionable threshold of 4.0 pCi/L.

If you have the room on your lit and decent soil it shouldn’t be very expensive to have a qualified septic installer increase the size of the drain field.

Yeah, it's near bathroom on the ground floor and no crawl space underneath.