A small Lower Hutt business says it will cost thousands of dollars to reopen after a fire tore through the restaurant.

Firefighters were called to fire at Roti Bay - a store popular for its roti wraps - about 1am on Saturday.

Owner Roshan Sheriffdeen said he was in shock when he got the call from emergency services.

He said he raced to the shop, and saw the large front window broken, some of his equipment outside, fire crews, and police cars.

"I couldn't talk ... it was emotional. So sad to see my shop gone."

Sheriffdeen said he understood an electrical fault caused the fire at the store he rents. However, a police investigation into the fire continues.

The broken window has been boarded up; past the burnt door an acrid stench lingers days after the fire.

Inside, the ceiling is black and peeling, looming over burnt menus and signage in the small shop.

Sheriffdeen opened the store in 2010, after moving to New Zealand from Sri Lanka.

He said he built the business from the ground up, providing for he and his wife's three kids who grew up with the store.

Now, Sheriffdeen said his landlord needs three months to sort out insurance, leaving the business with an uncertain future.

He said he expected to lose upwards of $100,000 in that time - in rent, staff wages, and food supply bills.

"It's gonna be really tough ... I can't work."

"It's a hell of a lot of money I have to pay rent here."

But the community has rallied around the family, raising over $6000 on a Givealittle page to help rebuild the store.

RNZ saw several locals come over to Sheriffdeen to offer condolences and hugs.

"I don't have any family with me, and I come here and now these people are my family," he said.

Students from St Bernard's College visited the store often, and expressed their support with a haka outside the store yesterday.

Sheriffdeen began cooking at his uncle's store called Bay in Tangalle, Sri Lanka, near the sea.

He named his business Roti Bay as a nod to his past.