Around 594,000 tonnes of carbon emissions could be cut by improvements such as installing solar panels, switching to LED bulbs and switching appliances off rather than on standby, the organisation said.
Mike Thornton, director of Energy Saving Trust Scotland, said: "Our homes are in better shape than a decade ago. Millions of cavity walls have been insulated in recent years and virtually no totally uninsulated lofts remain.
"We've now got to address leaky homes through energy-efficiency measures from lower cost draught excluders to higher cost wall insulation, encourage more people with suitable homes to invest in renewables and LED lighting and get people thinking about how, when and where they use energy."
Almost half say their homes have draught problems, 38 per cent experience condensation and 29 per cent have mould.