noun
common area maintenance fee; condo fees
A monthly fee paid by apartment or condominium residents for shared building expenses such as lighting, cleaning, and elevator maintenance. Often listed alongside rent or management fees.
家賃とは別に、共益費として毎月5000円かかります。
In addition to rent, there is a monthly common area fee of 5,000 yen.
このマンションの共益費には、廊下の電気代や清
The condo fees for this apartment include hallway electricity and cleaning costs.
修繕積立金 is a reserve fund for future large-scale repairs, distinct from the ongoing monthly common area fees (共益費).
Compound of 共益 (common benefit) and 費 (expense). The term is a modern legal/real estate coinage.