It is becoming more and more important for homeowners to consider alternative heating sources, it has been suggested.Daily Telegraph gardening expert Jean Vernon noted that as electricity and gas bills rise and people look for more eco-friendly ways to heat their homes, more may turn to firewood as an option.Many of us with largish gardens are already using them for a supply of kindling and firewood for open fires and wood burners, said the writer.But most gardeners could do a lot more to practice self-sufficiency in home-grown wood.Indeed, it was suggested that once people have compiled the right kit - a chopper, a saw, a mechanical splitter - they will be able to chop up large branches on site with relative ease once trees have been suitably and safely felled.Homeowners can also do their bit for the environment by making more efficient use of water in their kitchen sinks, as well as by implementing various energy saving measures.Earlier this week, meanwhile, the Association of Residential Letting Agents (ARLA) argued that people should try to improve the efficiency of houses before they are forced to do so by government regulation.