The Fire Service says it's still too early to identify what caused a house fire in Lower Hutt.

It took more than 30 firefighters several hours to bring the blaze at the two-storey Normandale Rd address under control.

Crews were called to the fire around 4.15pm yesterday, and had to call for back up three times.

No one was injured, but the young family with two small kids who lived at the property are understood to be devastated.