Valuers know jack about anything but valuing - and often not even that.
Despite what the valuer thinks or states (which is after all, only for the purpose of and benefit of the mortage company lending the money and nothing else), the problem you will have is when you come to sell and you get a more clued up surveyor working for the buyer, or a rare clued up valuer working for the buyers lender, and you will find that you can't sell it as a two-bed and will only get whatever a one-bed property is getting. That is the risk you take
Despite what the valuer thinks or states (which is after all, only for the purpose of and benefit of the mortage company lending the money and nothing else), the problem you will have is when you come to sell and you get a more clued up surveyor working for the buyer, or a rare clued up valuer working for the buyers lender, and you will find that you can't sell it as a two-bed and will only get whatever a one-bed property is getting. That is the risk you take