[Forest Keeper]

I’m guessing the local Bishop would have to approve of the plan, oversee it, and ensure it is properly consecrated upon completion.

Thanks, Scotswife. I wasn't sure if the Vatican (or a Cardinal, etc.) was directly involved with this sort of thing or not. I figured "somebody" had to sign off on it. :)

[Campion]

The local bishop has to give permission for the erection of any sort of Catholic chapel in his diocese, if the Blessed Sacrament is to be reserved there.

That would include any parish church. He would also normally perform the actual consecration liturgy of a parish church in his diocese.