I think I understand this now. However, if the estate is not going to sell the property (other than in a potential "buy out" transaction with one of the beneficiaries), then it doesn't really matter (at least not for purposes of the probate process) what the value of the house is.
Unless your father's will specifically says that your brother gets the house, it's not up to him to decide this. If, in fact, your father's will simply says that the estate (not merely the house) is to be divided evenly between you and your brother and whoever the other beneficiaries are, then any distribution of estate assets (as opposed to liquidation) can happen only by approval of the probate court (which probably isn't going to happen without all of the beneficiaries of the estate agreeing to it).
Getting back to your original questions, I assume what your brother is doing is proposing to you and the other beneficiaries that he should get the house in lieu of a cash distribution of the estate. It also sounds like your brothers 1/Xth share of the estate is less than the value of the home. If that's correct, it sounds like maybe he is intending to pay the estate the difference between the home's value and his 1/Xth share and is trying to reduce that amount so that he doesn't have to pay as much. All correct?
It's certainly "appropriate," "legal" and "acceptable" for him to propose this, but he can't impose it on you and the other beneficiaries unilaterally. If you don't buy into what he's proposing, then simply tell him no. If he starts to push too hard, then you (either on your own or together with the other beneficiaries) can retain an attorney to ensure your interests are protected. I agree that your brother may be skirting a fine line between his fiduciary duties as the executor and his own self-interests.
Thank you for this. Yes, my brother is trying to reduce the amount so that he doesn't have to pay as much. He is, in his own words, "House rich and cash poor." My siblings and I are not entirely pleased with developments and will take all of the suggestions from this thread into consideration. Thank you for your time and advice.