first right of refusal

[David Finley]

I have a question. I have a tenet on a commercial property that added a first right of refusal on the lease for another building on the property but only half of the building.  We signed the lease without noticing the additional item that he put in.  Nothing was discussed on having the first right of that additional building just an additional office in his current building. We have rented out the other building the tenets rented the whole building not half and he has came back saying he wants the first right to refuse on that other building. The question is does anyone have any experience on first rights of refusal and don't it apply to like to like or the terms that are set out in the process? Also I know that I should had read the lease again but since it is clearly additional item would you think I could easily fight that in court since it is not initialed.