Inherited share of house

[MyFriendFlicker]

Not strictly true but I am sole executor for my late mother. There is a property worth about £150k and a very small amount of cash. All well below IHT threshold. I am dealing with this so far without a solicitor and have got probate.
The estate is shared between me and my sister. Neither of us are in a hurry or in need of the cash. I am minded to keep the house and let it out but sis isn't interested and wants to sell.
So I could buy her out.
There are a number of problems.
Any valuation done now would be based on the market as it was a few weeks ago, EAs vary between optimism and gloom as to what will happen after lock down. In any case they can't do a valuation just now.
One has suggested that I may have to pay stamp duty on the entire value which doesn't sound right?
I will seek legal advice but wondered if anyone had had a similar experience?
I have also thought of transferring the deeds into our joint names for now so that I can complete the estate as I'd rather have my affairs in order.

You can only buy the house if your sister agrees the purchase price. If she doesn't you have a conflict of interest and would need permission from the courts to sell the house to yourself.

You would be buying the house from the estate so yes, you will pay stamp duty based on the entire value. The fact that half the estate will come to you is irrelevant. Technically, you would be paying the full purchase price to the estate but getting half of it back from the estate.

Since your sister wants to sell, why do you think she would agree to putting the house into joint names?

Thanks prh47bridge.
It would all be with full agreement, she is perfectly happy with whatever I want to do. We would get three valuations and agree somewhere in the middle.
I suggested the joint names thing as if I die* before I complete the estate, then it would fall to my executor to finish off my mother's estate.

• Not in brilliant health and with risk of coronavirus.

I didn't know about the stamp duty on the whole property, just done a quick calculation and it's a big chunk. Hmm.