Reducing Capital Gains with adjusted cost basis/ self contractor payment

[Jeff Brown]

Hey guys, this falls under a tax strategy question, however some of you may have had this scenario happen before.

I'm looking to sell a commercial property that has one renter in the building (business commercial). The subject property is over 100 years old, so it's useful life when I acquired it was depleted. It was purchased one year ago (falls in long term capital gains). I have not reaped any benefits of depreciation on the property (no need for recapture). The first year I performed a tremendous build-out; new plumbing, electric, facade improvement, new entrance for separate floor in building etc. I have changed it's current state to a more stable and useful floorplan, improved it's zoning and have put a tenant in place.

My situation is, aside from keeping all the receipts for materials, I did primarily all of the work (around 8 months) and I did not pay myself. I have past GC experience so I pulled all my own permits (which the city allowed because I owned the building and I wrote myself a lease to a LLC I was owner of). Now since I have not paid myself, and I only have the materials to show on paper, when I go to adjust my cost basis this is my dilemma:

I own the building (in a LLC) - I worked on the buiding (without pay) - but since I own the building and did the work, even if Building LLC paid myself through my Real Estate Practices LLC a large check for work performed, that's still taxable income because I am the pass through entity on both LLC's, so it seems to defeat the purpose. What is the best way to deduct my work performed to reflect a higher cost basis and not pay taxes twice?

Thanks for what I know will be great advice!