The cause of a house fire in Waihi on Friday is being labelled accidental as a fire safety officer continues his investigation into the blaze.

The Waihi Fire Brigade was called to the fire on Barry Road at about 10.30am to find the house 'well involved” in fire.

A house on Barry Road, Waihi, was badly damaged when flames engulfed the building on Friday.

At the time, Northern Fire Communications shift manager Scott Osmond said it was a substantial fire and the house was badly damaged.

'Luckily, no one was home at the time,” says Scott.

Tauranga fire risk management officer Bill Rackham was called to the fire to investigate the cause.

'My investigation is currently still underway,” says Bill. 'I believe the cause was accidental.

'I am focusing my investigation on a personal electronic device that was plugged in to charge the battery and left on a couch while the owner had gone out.”