If there are good reasons why you can't work from home, then you can't work from home. Good reasons why you can't work from home are rare - maybe because you are homeless, or you live in a place where you can't be indoors during day time. If you refuse to work from home because you don't like working from home then you are refusing to work. Most likely your employer will take it as you taking a holiday if they are nice about it. If it is going on over weeks and you run out of holiday, the company will stop paying you. They can also probably fire you quite quickly about refusing to work, which is a breach of your contract.