Rezoing a land from R4 to commercial.

[Zin Tun]

I found a property under contract that has R4 zoning with some sensitive area. It is under contract with me and after initialy survey done, the land has a lot of sensitive area and found that I can only build a house based on R4 zoning. But if I can change to commercial zone, the value of the land will be a steal. It is currently valued at 250k by the government based on tax history and the seller agree to sell me for 135k. If I build a single house, I probably just break it even or might get 5 to 10% profit in the overall process. Any advice and has Anyone done rezoning from residential to commercial?