Is it possible to work from my parents' home on a postdoc? I have a postdoc (in mathematics) lasting for less than 8 months. In the UK, at the area of the university, I find it difficult to find accommodation since no one wants to let to me for such a short period of time, which is very annoying. 

I was thinking I could live with my parents, and visit my adviser once a week or so. The journey would be about 3 hours each way. And we could Skype.

As a PhD student, this would have been acceptable, but I wonder if it is different since I am now a member of staff. Is it frowned upon? Will it cause problems for the department (eg. desk space) or for myself due to tax purposes? It's an EPSRC funded grant, so I wonder if that may also be an issue.
Only your school and your department and your group can tell you what their expectations are. Ask them.

But face-to-face networking with others is hugely valuable both for your current tasks and for being aware of new opportunities,, and think carefully before you give that up. I've been working from home for about 5 years now (commercial, not academic), and it has definitely cost me in terms of career progress despite my making deliberate efforts to stay in the loop.