Presumably these house owners must've been listening to Kevin McLeod (Grand Design bloke) who says if we want to meet the growing need for cheap 'affordable housing', we should model ourselves on the Victorian builders, who leased land and threw up street after street of houses at lightening speed. News for you, Kev mate: we're already there.
All my four Victorian Detective Series books are set during the great Victorian house building boom, when speculative London developers maximised their profits by using cheap cement, known as Billysweet, which never dried out, so these houses actually had their own internal weather system.
They also had no proper foundations, and floorboards laid on bare earth. As a direct result, by 1865 London had some of the poorest people living in some of the worst slums in the kingdom. (In those days, the immigrants were Huguenot silk weavers escaping from France, Irish escaping from famine and Jews escaping from Christians.) Some streets, especially around Kilburn, in North London, acquired 'slum status' from the moment they were built.
At the same time, Parliament passed the Poor Law Act in an attempt to stop anyone who could work from receiving parish relief - it was thought that poverty was caused by 'moral failure', and paying such people only encouraged them to be idle and overpopulate. Is this resonating?
Dickens described these MPs and their property-owning chums as 'Experimental Philosophers ...whose blood is ice,whose heart is iron.' I guess now we'd call them: 'Rich arrogant posh Tories who don't know the price of a pint of milk.'
Nothing much changes ....