[Martin ccs]

just wondered when we are working on someones property, who is liable for any accidents?

the owner or workman?

[michael papworth]

It depends entirely upon who's at fault.

If you cause damage to the owner's property or person by your actions or negligence, it's your liability.

If the property owner causes damage to your property or person by their actions or negligence, it's their liability.

[Ian Lancaster]

There is another consideration: while you are working on a property, you are deemed to be the employee of the property owner, especially where H&S is concerned.  Theoretically the owner is responsible for ensuring you have a safe working environment, and that you use proper safe working practices.  If it could be shown that the owner had not ensured this and you had an accident, the owner could be prosecuted under the H&S at work regulations.