The taxidermist - who moved to Queenstown four years ago following the Canterbury earthquakes - said his first concern was his new black labrador puppy, which he had left at home while he went to see friends on holiday from the North Island.
"When I got home I almost crashed the car.
"That was my first worry ... she's all right; she's a bit frantic."
Crews from Arrowtown, Frankton and Queenstown were called to the property, in Arrow Junction Rd, about 6.15pm after one of Mr Jacobs' tenants, who lives in an adjoining flat, smelled smoke.
"She turned on the telly for the six o'clock news and she could smell something.
"They think it might have been the computer, or something in the office anyway, but ... I was only out for, like, 20 minutes and "woosh".
Mr Jacobs, who is insured, said he was also grateful a track had just been cut to a water tank behind the property - and that his smoke alarms had worked.
While there was likely to be extensive smoke and water damage to the property, Mr Jacobs planned on staying last night with his friends at a bed and breakfast they'd hired.
Last night, however, he was trying to look on the bright side.
"It's still standing."[With] earthquakes they don't usually stand after an earthquake, so that's a good, positive thing."
Arrowtown Volunteer Fire Brigade station officer Nathan Clark said by the time crews arrived at the property smoke was coming out from under the eaves and a crew wearing breathing apparatus was sent in.
Fire safety investigators would work today to determine the cause.