A NSW couple leased an apartment for just over 12 months from an owner, who managed the property himself. During the tenancy, the couple carried out various modifications to the apartment with the owner's consent, including the installation of light fittings, shelving and blinds. When the tenancy ended, the owner lodged an application to the NSW Civil & Administrative Tribunal, under section 69 of the NSW Residential Tenancies Act 2010, seeking compensation for the cost of rectification work required as a result of the alterations made to the property. At the hearing, the owner conceded that he had consented to any alterations, "as long as it adds value to the property". However, he was shocked when he discovered the extent of the alterations, and was now seeking compensation. The tenants replied that every alteration was made with the owner's consent, and that he had even agreed to reimburse them for their expenses.

a. What would the tribunal need to consider before making a determination