Building an Additional Rental Unit (ARU) on Kauai is one of the smartest moves to boost your property's value, especially in a high-demand area like Poipu. Since your property already features a "large yard" and a "cool breezeway," you likely have the physical footprint to make this happen.
Kauai’s ARU program is specifically designed to add density to residential lots. Unlike a traditional guest house, an ARU can be rented out independently. Here is what you need to keep in mind for your pocketbook:
Water & Sewer: This is your biggest hurdle. You'll need to confirm the Department of Water and Wastewater Division have capacity for the extra load.
Size Limits: ARUs on Kauai are generally capped at 800 sqft or a percentage of the main dwelling's size.
Parking: You must provide at least one additional off-street parking space for the new unit.
Design: Since you're in the historic Weliweli track, you'll want the unit to match that "Old Kauai" charm to keep neighbors happy and property values high.
| Development Factor | ARU Standards |
| :--- | :--- |
| Max Unit Size | Up to 800 sqft |
| Permitted Use | Long-term or mid-term rental |
| Parking | 1 dedicated stall required |
| Utilities | May require separate meters |
Since your main home is already pulling a strong $5,495 rent estimate, adding a small 1-bedroom ARU could realistically add another $2,000–$2,500 to your monthly cash flow. Just double-check that there aren't any specific subdivision CC&Rs for Weliweli that restrict additional structures!