A spur-of-the-moment decision to take his mother-in-law out for coffee was all that saved a Napier man from being killed when a drunk driver reversed repeatedly into his house.

Sea Breeze Bed and Breakfast owner Cafer Unac should have been sitting in his bedroom on his computer when a car came crashing through his front wall yesterday morning.

But he had ducked out to have a cup of coffee with his mother-in-law.

"I was so happy I wasn't here. Otherwise I would have been sitting in the room doing my emails."

Witnesses said the driver reversed out of a Marine Pde car park, across a traffic island, and into the Sea Breeze.

The driver then drove forward and reversed back into the historic building a second time.

The crash caused major damage to the front of the building but Mr Unac was confident it could be repaired quickly so that he could resume business.

His guests had left before the accident, which occurred just before 10am.

Auckland man Warwick Callaghan, who was on the footpath outside the neighbouring youth hostel, said the car came within a metre of hitting him.

"I could have touched the car as it passed.

"I thought he was trying to run me down."

He estimated the late-model Mitsubishi Diamante was travelling about 60kmh.

He said it hit a parked car in the southbound lane of Marine Pde, then reversed over a kerb and through plants on a raised traffic median before crossing the northbound land and smashing into the bed and breakfast.

"I was shouting at him through the window to get out of the car. I said, `Look what you've done to the building, you might have killed someone and you might kill yourself if you keep going.'

"He just gave me a vacant look."

Police said a man was in custody and was likely to face charges of reckless driving and drink-driving.