Don't start with the kitchen or the bathroom.

I think people might get scared of having multiple of everything (4 bathrooms, 4 kitchens, 4 HVACs) that could break and need cap ex, but another way to look at it is that you're vacancy wallet is 1/4 as liable since the others can subsidize.

We updated the bathroom, replaced the deck and the fence.

Kitchens and bathrooms, updated fixtures and flooring will always increase interest in a property, but how much it increases value or rental rates would depend on where you are.

It would be a 3 Bedroom / 2 Bathroom will a parking space.The cost of the renovation we're estimating as over $100K.

I doubt that too; maybe it's just me but it puts me off to see carpet in a bathroom situation and in a place that may or may not have moisture issues - I'd just as soon see the floor painted and put down an area rug. 

I learned this after having the same bathroom torn apart twice a year apart.

I think there is a fixture in the unit bathroom that is not sealed properly and leaks when the owner is using it.

You have to account for HVAC,hot water heater, kitchen remodel, bathroom remodel, etc.

The home bed the following repairs;New doorsNew windowsFresh paintRefinished hardwood floorsNew central airBlock off doorway connecting two apartmentsLegally change zoning to 2 family2 New fridges 2 new stoves 2 new washers 2 new dryersNew bottom cabinetsNew countertops Install light fixtures in each roomReglaze tubs Replace bathroom fixtures Install sub panel for 2nd unit which previous owner removed.