Designing ADUs and Ohana Units in Kailua: Small-Footprint Luxury on Real Windward Oahu Lots

The finished Lanikai guest house — three bedrooms, two baths, and a garage designed into 800 square feet.

Everyone on the Windward side seems to be asking the same question right now: can we add an ADU or Ohana unit to our lot? The more useful question is how do you design one that actually lives well on a real Kailua or Lanikai lot — the small, sloped, flood-aware, salt-exposed lots that make the Windward side so beautiful and so demanding. We have designed exactly these, including a guest house tucked behind Buzz's Steakhouse in Lanikai, and a second one taking shape in our own backyard on Mokolea Drive right now.

Here is how we think about designing an Ohana that earns its place on a real lot.

The lot sets the rules — so we design to them

The Lanikai lot pools in big rains. We let that fact shape the design — elevating the home instead of fighting the water.

On Windward Oahu, the site is the first design input, not an afterthought. Our Lanikai guest house sits on a lot that pools with water in big rains. The design answer was not to fight the water — it was to raise the entire structure and let that elevation shape everything above it: how you enter, how the garage relates to the street, how the building meets the yard. A lot with flood history is not a disqualifier for an Ohana. It is a design brief. Some of the most characterful homes we have designed started as so-called problem lots.

What 800 square feet can actually hold

The finished Lanikai guest house fits three bedrooms, two bathrooms, a single-car garage, and an outdoor shower into 800 square feet across two stories. The moves are old ones done carefully: high ceilings that let compact rooms breathe, sightlines that borrow space from adjacent rooms, storage designed into the architecture instead of bolted on, and finish quality concentrated where you touch and look every day.

Small footprint does not mean small living. It means editing. A well-designed Ohana unit lives far larger than the square footage suggests — and in Kailua and Lanikai, where every buildable foot is precious, that editing is the whole game.

Built-ins do the heavy lifting: a custom bunk room sleeps the whole family without stealing floor space — storage and beds designed into the architecture, not bolted on.## Coastal materials, specified for the salt air

Coastal materials, specified for the salt air

A beachfront Ohana is only as good as the materials that survive the environment around it. Salt air is undefeated. Every fixture, hinge, and finish on the Windward side has to be specified for coastal exposure, or it will not last. In the Lanikai guest house that meant a custom staircase with glass railings — designed in partnership with a mainland manufacturer, with dozens of hours spent verifying exact measurements and fit inside a compact footprint — alongside high-end appliances, designer fixtures, and lush custom landscaping. The result is a private retreat that feels far more generous than its size.

We are living it twice

We are designing this again in our own backyard. The cottage replacing the shed at our Mokolea Drive home is a backyard Ohana cottage in the same language — flood-aware, compact, and designed to live large. We are documenting that series publicly as it takes shape, so you can watch the design decisions happen in real time.

Our own Mokolea Drive backyard — the next Ohana we are designing, a backyard cottage.

Thinking about your own lot?

We are a design-led interior design and renovation studio in Kailua. We design ADUs, Ohana units, and whole-home renovations for Windward Oahu lots — including the complicated ones — and provide full design and construction management from first sketch to final walkthrough. If you want a straight answer about what your lot can hold and how to make it live far larger than its footprint, that is a conversation we have every week.

Talk to us about your lot →