derelict house - household charge

hi just a quick query somebody may be able to help out on

my parents own a former rental property which has since
being abandoned and has being derelict for the past 5 years

the property is uninhabitable and is run down. there is no water supply/electricity and the roof is leaking water and the inside has being destroyed by previous tenants. the house is not suitable for occupation.

i have being made understand that my parents are not liable for this charge.

is this true and if so how do my parents go about getting this waiver or do they just do nothing as it is a self declaration tax ?

They are supposed to register and then claim the exemption.

yes i see that from the household charge website that you can claim for a weaver/exemption for certain things e.g mortgage interest supplement but it dosnt say anything about a derelict house ?
is a derelict house liable for the charge ?

I has a sneaking suspicion that it is liable.

Thanks for all the replies . As far as I can see my parents house would not be a residential premises according to the act . However there is not a section on the form or on the website to tell me what to do in this situation.Any ideas anyone ?

Do nothing.

and then they come after my parents in a years time looking for the money ? the house will still be derilict in a years time but my parentts would have to prove this.