House Flip with additional land to subdivide

[Patrick Gunn]

Hello. I have a recent property that was purchased and being updated on a very large corner lot that has potential to be subdivided. As you can see in the picture below how I would break it out. The magenta is the future buid-able area after setbacks. The large one is .23 and the smaller is .18 with the existing house being .17

My question is for purposes of investing should I be concerned with the decrease in value on the existing house if I do this? It does take away from the backyard but still leaves some. I dont want to do this and decrease the house value beyond what the lots would profit, which I dont think would happen but curious everyones thoughts. I think anywhere from 15-25k would be reasonable sale for each of the lots, but still need to speak with realtor to determine price.  Thanks