Unjust enrichment lawsuit over management authority, management fees and rental income from a large commercial building

This was a dispute between a management company that had managed a large commercial building for many years and the building's unit owners' association over management authority and the ownership of management fees and rental income.

The association claimed that the management company had collected management fees and leased out common areas for profit without proper authority, and sought the return of unjust enrichment.

Attorney Jaehoon Lee represented the management company on appeal.

The main issues were whether the management fees collected by the management company and the rental income from the common areas constituted unjust enrichment, and how the amounts actually received and the scope of return should be calculated.

Further issues were whether the costs the management company spent to maintain and manage the building could be deducted from its obligation to return unjust enrichment, or set off on the basis of a claim for reimbursement of necessary and beneficial expenses under the doctrine of management of affairs without mandate.

Attorney Lee reviewed materials on the management of the building and its leases, and analyzed whether each individual space had been leased, the actual rent and management fees received, and the scope of return.

In particular, to prove the personnel and operating costs incurred over many years of managing the building, he reviewed accounting and tax records, including income statements, tax invoices and withholding tax filings, and contested whether the unjust enrichment claimed by the association existed and in what amount.

He also reviewed the manager's right to reimbursement of expenses spent on maintaining and managing the building and the law on set-off, and presented arguments on appeal to limit the management company's liability to return funds.