Housing Refits
Although energy-efficiency measures are easiest to implement in new housing, you can also make significant improvements by refitting existing housing.
While new housing is now required to meet achieve at least a six-star NATHERS rating, some research indicates that houses built before this guideline came into force (that is, over 90% of Australian housing) achieve an average of 1.8 stars. This is a major contributor to our greenhouse gas emissions, and also means residents have to pay more for their energy. You can read more here: https://theconversation.com/house-hunters-are-rarely-told-the-home-energy-rating-little-wonder-the-average-is-as-low-as-1-8-stars-144873
Tenants are particularly likely to be living in housing with poor energy-efficiency. Private landlords have little financial incentive to upgrade the energy efficiency of their properties as their tenants, not them, get the benefit and even though they could potentially translate this cost saving into higher rents this is not always possible in practice. It’s even harder for social housing providers who are generally strapped for cash and whose tenants are on subsidized rents already. Yet there is clear evidence that more energy efficient housing is better for both tenants’ wallets and their health: see for instance https://theconversation.com/sustainable-housings-expensive-right-not-when-you-look-at-the-whole-equation-60056
While you may not be able to afford a full refit, there is a lot you can do at low cost, and often in the course of ordinary planned maintenance. The Cooperative Research Centre for Low Carbon Living has developed a handy guide for social housing refits which grades potential refits from simple/low cost to complex/high cost. You can check it out here. The Green List has a handy taster here.