"If you break it down to the basics, you talk about passive design which is using what you have got, the sun, the sun's orientation and local climate.
"You can use local climate to control how warm or cold your house is. With correct orientation and correct materials there is nothing saying your house can't gain and maintain heat right throughout the year and with correct window placement and control you can cross-ventilate in summer by using local wind patterns."
Event manager Dayna Comeskey said sustainability was no longer a niche market, as mainstream consumers looked for more information and product alternatives.
The event was the perfect opportunity to bring together a great range of sustainable options and experts under one roof, she said.
"There are so many of these products available and the expo is making them easily accessible to Bay residents."
Feedback from exhibitors and the community had been positive, with plans afoot to hold the next expo in September, next year, she said.
This weekend's Down to Earth Expo would showcase everything from sustainable building and renovation options to the latest food, beverage and health products and alternatives for the garden and pets.