In a residential lease, the maintenance and repairs necessary to keep the leased premises in a livable (habitable) and safe condition are generally the responsibility of the landlord—unless damages are caused by the negligence or intentional conduct of the tenant or the tenant’s guests. In that case the landlord will likely maintain the right to make the repairs and charge the tenant for the repairs, and not allow the tenant or the tenant’s contractors to make the repairs.

The written lease agreement should address the responsibility for maintenance and repairs and will often prohibit or limit the tenant’s ability to do any maintenance or make any repairs—at least without the written permission of the landlord. One exception may be the tenant’s right to make repairs in an emergency situation to prevent harm to the property or its occupants.

In some limited circumstances a landlord may allow the tenant to maintain and make repairs to the leased premises when the landlord is confident in the tenant's ability to properly maintain the property and make the necessary repairs.

In New Jersey, the landlord is generally responsible for maintaining and repairing the rental property to ensure it remains habitable and safe, as per the state's warranty of habitability. This includes fixing structural issues, plumbing, heating, and other essential systems. If the tenant or their guests cause damage due to negligence or intentional acts, the landlord can repair the damage and bill the tenant. The lease agreement should clearly outline the responsibilities for maintenance and repairs, and typically restricts the tenant from making repairs without the landlord's written consent. However, in emergency situations, tenants may have the right to make necessary repairs to prevent further damage or harm. Some landlords may permit a tenant to handle maintenance and repairs if they trust the tenant's capability to do so properly. It's important for both landlords and tenants to review and understand their lease agreements and New Jersey's landlord-tenant laws to ensure compliance with maintenance and repair obligations.