The one-day hearing for those interested in seeking standing will take place Oct. 26 at a motel in Elliot Lake, a commission spokesman said Tuesday.
Mark Wallace, one of the inquiry's lawyers, said he couldn't tell how many applicants might want standing, which will allow them to get legal funding and examine witnesses.
"The unknown variable would be the number of people or groups from within the community that would be applying," Wallace said from Ottawa.
Wallace said only one day was needed because the applications need to be done in writing — the deadline is Oct. 17. Commissioner Paul Belanger could make a decision based only on the paperwork and some may opt not to make an oral presentation.
It will be at Belanger's discretion as to when he makes his decisions.
The inquiry was called after part of the rooftop parking garage at the Algo Centre Mall collapsed in June, killing two people and injuring several others.
The probe will look at the causes of the collapse as well as the emergency response, which some criticized as slow and inadequate.
Those with a "substantial and direct interest" or whose participation could be helpful to Belanger are being urged to apply for standing.
To date, the commission has sent out more than 40 "summonses" to organizations such as the municipality of Elliot Lake and ministries of the provincial government demanding production of documents. Some summonses request explanatory or other reports.
Recipients are legally obliged to comply with the demand.
The commission will have to pore over the returned material and do a "very time-consuming" review to determine their relevance before they can be shared with inquiry participants, Wallace said.
"That's occupying a significant part of our time," he said.
Commission lawyers have also been interviewing people in the community.
Actual evidentiary hearings were scheduled to start early next year, and Wallace said it appears the commission was still on track.
After the collapse, many residents said the mall had frequently leaked and showed clear signs of damage, but one municipal source said no one ever formally complained.
Inspections apparently turned up nothing potentially catastrophic.