I don't like this house very much. I first purchased Hjerm but then I purchased the house in Solitude (Proudspire Manor) in my opinion Hjerm is much better because it is much more spacious and has much more storage, besides it was very expensive! Lol
I don't like that house very much : yes, it has a lot of storage space but it's also dark (at least in the first floor) and you have to do the Civil War and have the murdered woman's family alive to acquire it. I prefer to build or to buy Severin Manor or Proudspire Manor.
acctually, you can get the key if the shatter-shields aren't still alive, and even then, the key can be looted of tova's corpse if she dies/commits sucide. you cant upgrade it until completing blood on the ice though.