Ranging in cost from $5 to $500, the models are a broad selection of trucks, tanks, boats, planes and military vehicles.
Of those 420-odd models, only about 100 have been built.
Surrounded by boxed and constructed models, with a model train track in the centre of the room, Mr Hills said the hobby, which had been moved from the kitchen table to the sleep-out, was about enjoyment.
''The worst part is finding a place to put all the finished ones.''
Being a modeller did not take any skill at all, Mr Hills, who is a mechanic, said.
''Just a little patience is all. If you don't have any, you can still put a model together that looks something like an aeroplane.''
For him, models were about the pleasure of building something that looked good.
''Some people build furniture that looks really good ... I build models.''
There did not need to be any reward, it was just about fun.
Although he only spent about an hour a week on his models, he wished he could spend more, he said.
The average model could take about 20 hours to complete, but his model of the Titanic had taken about 180 hours because of the level of detail.
While he was not a history buff, during construction of many models from military history he had read books about what he had been building, and learned about them.
A member of the 16-strong Central Otago Model Society, Mr Hills will be among a group of people at Alexandra Community House today during a ''Give it a go'' day.
During the Art Craft Incorporated-organised event, people will be able to attend and learn how to construct and decorate a model aeroplane, provided free of charge by the model society.
Organiser Kathi McLean said a lot of people in the town did not know about the different activities on offer in the town.
The day would offer people a chance to learn about the groups without any cost involved, and an opportunity to take a step further and join them if they wished, she said.
Other groups at the event will be the Central Otago Arts Society, the Alexandra Patchwork group and Alexandra Sewing Circle, the Spinners and Weavers, and the Alexandra Pottery Group.
The day, running from 10am-3pm, will provide the public with an opportunity to try out any of the crafts free of charge.
Mr Hills said the event was a membership drive by the model society, as it hoped to attract larger numbers to the group.
Although there were junior members in their teens, most in the group were older than 50.
Models constructed by the model society from World War 1 and the Vietnam war are on display at the community house as a part of commemorations of each war.
