Adding a unit to duplex - lot 33sqft too small - what to do?

[DG A.]

Hi Folks, 

I want to add a 3rd unit to a duplex I own, but my lot is 33 sq. ft. too small. Here's the deal...

I own a duplex that sits on a 7,467 sq. ft. lot and it's located in an RM-2 Zone in Oakland, CA. 

I've looked up the sq. ft. requirements for the RM-2 zone and the planning code says you can have 3 or more units on the lot, as long as there is 2,500 Sq Ft of lot area per unit. So, in order to have 3 units on my lot I would need a 7,500 sq. ft. lot.
  

See here: 

My lot is 7,467 sq. ft. which makes it 33 sq. ft. short of meeting the conditional use criteria of 2,500 sq. ft. per unit to be able to add a 3rd unit to my duplex.

Questions:

• Has anyone out there solved a similar problem? 
• What do I need to do to find a way to add my 3rd unit? (Neighbors are not interested in selling me 33 sq. ft. of land)
• I've heard about cities allowing variances, but I'm not sure how they work or if I would qualify for a variance to the planning code in my situation. Has anyone out there successfully gotten a variance? Would you share your experience?

My duplex is in Fruitvale, not that far from Lake Merrit.