New siding, exterior paint, new roofs, interior improvements and new common area amenities have been installed and created.

Interior Rehab, unit conversions and expense reduction

Interior Unit Remodels, Unit Conversions, expense reduction, Other Income increase

Interior Unit Remodels, Unit Conversions, expense reduction, Other Income increase

Completely renovating the interior and exterior.

Interior is usually about 25k per unit.

For interior work, perhaps it goes without saying that demolition has to happen first. 

We installed new cabinets, removed a wall to open the space, new granite countertops instead of laminate, replaced the carpet with Lifeproof LVP, did a two color paint scheme on the wood paneling, remodeled the master half bath, refinished the tub in the full bath, new vanities, new appliances, and new six panel interior doors instead of slab.

@Eric RubySince you have a legally existing 2-unit building; you should be allowed to perform the "Interior remodel" you mentioned in order to reconfigure the 2 units; and since you have a legally existing 2-unit building, and will be keeping it as a 2-unit building; you should be okay from a Zoning standpoint even if the Zoning designation doesn't allow for the 2 Units "By Right", as your building would be grandfathered in, as long as it is a Legally Existing 2-Unit building (i.e. the 2nd Unit wasn't constructed illegally).After that, the bigger concerns will be complying with the building codes; which it sounds like you already have some thoughts on how to meet the major concerns.

At least where I am, you don't want to be replacing a roof in the winter.Leave the interior updates until they move out.