Selling a home or rental in Hawaii can trigger a big tax bill, but a few basic moves can shrink it — good news for owners who plan ahead.

• Profit on a property sale gets taxed, and federal plus state taxes can take as much as 30% of the gain.
• Keeping receipts for major work like a new roof raises what the property "cost" on paper and cuts the taxable profit.
• Rental owners face the opposite effect: past depreciation write-offs get added back and make the taxable gain bigger.
• A main home lived in for at least two of the past five years qualifies for a tax-free gain of $500,000 for couples or $250,000 for singles.
• Timing matters for older owners who may need sale proceeds to pay for assisted living or nursing care.

Outlook: With so much Hawaii wealth locked up in property, owners who track improvements and time the sale carefully will keep far more of the money.