The cold cellar contains two jars, a folding chair, and the belief that it could be an office. It might become useful space. First, decide whether it is staying a cold cellar.
Choose which side of the house boundary it belongs on
NRCan's basement guidance describes insulating the separation between a heated basement and an unheated cold cellar. Converting the cellar is a different proposal: the thermal and air-control boundary may need to move.
Have the designer assess the slab, walls, overhead structure, moisture history, and connection to the rest of the basement. Sealing the vents is not a complete conversion design.
Test the intended use honestly
Measure finished height and usable width after the proposed assembly. Consider daylight, ventilation, access, and the temperature expected in that room. An office and a storage room make different demands on a small enclosed space.
Compare conversion with better separation
- A properly assessed conversion to conditioned space.
- Retaining an unheated cellar with a better separation from the basement.
- Improving storage and access without changing the room's environmental role.
Ask the municipality what approvals the proposed use and construction require. Avoid describing the project as just insulation if it includes structural, mechanical, or layout changes.
A cold cellar does not need to become a bedroom or office to earn its place. The sensible option is the one that gives it a clear job and a coherent building detail.