I'm in the process of getting quotes to have an existing concrete driveway (approx 140 sq/M) dug up & replaced with a new sub base surfaced with tarmac. I'm getting conflicting advice (& prices) as to weather or not I need an Aco drain into a soak away across the bottom. Now I know regulations on drainage onto the highway changed some years ago but can anyone give me a definitive answer as to weather or not they apply to replacing an existing drive way?