I live in City of Melville. Their planners are quite good and approachable and I imagine they will say its technically possible.
But what's the end goal? I imagine you could bulldoze both houses and get 3 lots at R20. But I'd be surprised if that was worth it.
Its a much more difficult process than probably most people realise. I'd be surprised if it was possible with the numbers also working out.
I wouldn't suggest it if you're just starting out in property investment.