The Riveaux Road fire continued to threaten numerous communities southwest of Hobart.
Chief Officer Chris Arnol confirmed that three homes in the Glen Huon area were destroyed overnight.
"These homes were destroyed after they either came under ember attack or direct combustion by radiant heat," he told reporters.
"The homes that have been lost were within the warning areas in Frypan Road and Bermuda Road.
"Owners have been notified. We're grateful they're safe. By all reports their properties would have been undefendable. Their decision to leave early ... saved their lives."
Mr Arnol said he expected "further structural losses" but was pleased most people were following advice to evacuate.
An evacuation centre at the Huon Valley PCYC has housed hundreds of people for days, including Glenda Stokoe, 49, who has lived at nearby Geeveston with her husband for 14 years.
She left home on Monday leaving her husband to fight the fire.
"I've never seen it this bad. Everyone is on edge, they don't know what they might be going home to," Ms Stokoe told AAP.
Her home is just a couple of kilometres from tourism drawcard, the Tahune Airwalk, which has been closed for almost a week amid the bushfire threat.
While the airwalk's visitor centre was saved by firefighters overnight, other parts of the property were damaged or destroyed.
Not far away at the Southwood wood processing site, a fuel storage shed and chemical storage areas were damaged.
Police have urged fleeing residents to lock their homes after a 42-year-old man allegedly looted several properties in the Huon Valley area on Monday.
"Thieves are often opportunistic and I urge everyone to lock their belongings to prevent being a target of burglary," Inspector John Ward said.
Temperatures are forecast to peak in the mid-30s on Wednesday, when another 60 interstate firefighters are expected to arrive and join the battle.
"This fire fight is not over. We've got a long period ahead of us of no rain so there's no respite ahead of us," TFS District Officer Andrew McGuinness said.
The second fire carrying an emergency warning has been burning for almost a fortnight at Great Pine Tier in the state's central plateau.