The house on Swamp Rd, north of Leeston, was engulfed in flames when fire crews from Rolleston and Burnham arrived shortly after 5.30pm.
Extra resources were called from Lincoln, including water tankers to tackle the fire at the rural property.
It took firefighters an hour to contain the fire by which time the house was extensively damaged.
A fire investigator will look at the possible cause of the fire today, which is not being treated as suspicious.
One person was treated by ambulance from smoke inhalation, Fire and Emergency shift manager Lyn Crossan said.
A post on the Leeson Volunteer Fire Brigade Facebook page said the fire had hit "one of our own".
The post said the house belonged to a family of two adults and four children aged 6, 5, 4 and 2.
"The most important part is they are safe, but all they have left are the clothes they stand in."
Scores of people responded to the post with offers of household goods, including a wooden table and chairs, a leather rocking chair, several beds, clothing, toys and even make-up and skincare products.
The local fire brigade plans to set up a Givealittle page.
Crossan said the public should never underestimate how quickly a fire can spread.
