Actually I think environmentally there is a point - if you're renting a house, then you can't make changes, and the landlord has no motivation to upgrade for changes (in fact, they can only claim as an expense like-for-like maintenance, not improvements) - so for example, the house I'm renting has no thermostatic radiator valves, poor insulation, the hot water tank is barely lagged, the loft not insulated at all and the windows are drafty, and I have an ancient controller for the boiler, so if I want hot water I get the heating as well (unless I run around the house turning all the radiators off myself). The appliances are all ancient and cost a fortune to run.
In the house I used to live in and now rent out in another part of the country, I'd upgraded to a combi boiler, so water is heated as needed and there's no hot water tank, all the radiators have thermostatic valves, there's new double glazing and doors, insulated everywhere. All the appliances are energy efficient, and the energy consumption as a result is very small.
I think that there needs to be regulation around the rental market, so landlords have to make improvements to their housing stock in line with current energy saving standards (probably not up to the standard of new builds, but what is practicable given the existing house)