Woman's face burnt in Sydney house fire

A woman has suffered facial burns in a fire that's destroyed a home in Sydney's southwest.

The house was well alight when firefighters were called to the blaze in Moore Street, Campsie at about 9am on Monday, a Fire and Rescue NSW spokesman told AAP.

A 40-year-old woman suffered burns to her face and was taken to the Royal Prince Alfred Hospital, while another person escaped unharmed.

The injured woman was also treated for smoke inhalation.

An investigation is underway into what caused the blaze, which authorities say completely "destroyed" the house.