Bob Bradshaw (77) worked at the former municipal supply gasworks for about 25 years, until shortly before it closed in 1988.
And he has been a volunteer supporter of the subsequent gasworks museum at the Braemar St site for more than 20 years.
There had been many frustrating delays in developing the museum over the years, but progress was now being achieved, including on the previously endangered museum fitting shop, he said this week.
All too many of Dunedin's old buildings had been "bowled over".
The main building contractor is Stevenson and Williams Ltd.
Architectural planning for the restoration and redevelopment project is being undertaken by Ian Butcher Architecture Ltd.
The roofing and much of the external work had been completed. Double-glazed windows would soon be installed in brick arches, and internal painting was under way, Mr Butcher said.
"I'm delighted by the standard of worksmanship."
The project had been "quite challenging", involving righting brick walls out of alignment and other difficulties, but it would be completed in about a month.