Wrong council band?

AiAka

Hi. 
My parents think their house is in the wrong band. My dad contacted them about it a few years ago and they told him to find a property similar/same size as our within 2 miles that's a different tax band. But he couldn't see ones that were similar except the ones down our cul de sac. 
 My parents house is a detached house that is similar size to some of our neighbours but they are also in the same band C. The other detached houses down our streer are bigger and they are also in tax band C (they also have porches and garages on theirs which we don't). 
I can't remember the exact amount my parents payed but i know it was definitely 30 odd thousand pounds in 1987 and was a new build. 
We have tried looking up when the house sales were online but the first one showing is in 1996 and that was for £41,500. That is one of the bigger detached houses with a porch and garage. Our neighbours that have similar sized properties but they have owned there's since 1987 like us so I can't check sales. 

Does anyone know if there's anything else to challenge? Or is that it.

Thanks

lincroft1710

The fact there are bigger houses in Band C won't help you as there will be many different houses in the same band. You will have to try to find detached houses of a similar size and age in a wider area in Band B. but there is no guarantee the VOA will accept this as useful evidence.