Mr Tempero (47) cleaned out the shed, just south of Oamaru, during the Christmas holidays and has just completed his first car in it - a replica 1952 Maserati A6GCS coupe.
The car, which is destined for a private Maserati museum in Auckland, was "fantastic" to drive, he said.
The Tempero Coach and Motor Company was established by Alan Tempero in 1946.
His son Errol took over in 1970, and he was joined by his son, Rod, in 1977.
Errol Tempero sold the business in 2002 and Rod Tempero continued to work there until earlier this year.
Yesterday, Mr Tempero said he would be both building and restoring cars, and he was expecting both domestic and international customers.
Among the business received to date are orders for a 1967 Ferrari P4 and a 1957 Lister Jaguar, both for New Zealand buyers, and a D-type Jaguar for an American.
Building cars was Mr Tempero's interest as well as his work, and his new workshop - minus the chooks - was proving an ideal location.
He has employed one staff member.
The Black Diamond Trail expedition across North Africa, which Mr Tempero will travel with, has been delayed until September next year.
Mr Tempero will drive his World War 2 Chevrolet truck 3500km from El Alamein to Tunis.
His truck will be one of two used on the expedition, which will include a documentary film crew.
