New Construction Plumbing on O'ahu
Building a new home, ADU, or addition on O'ahu? Alpha Omega provides full plumbing services for new construction — from underground rough-in through finish fixtures — with permits, inspections, and the Hawaii-specific knowledge your project needs.
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What We Do
New Construction Plumbing Services
Everything your new build needs — from the first underground pipe to the last fixture connection.
Underground Rough-In
We set all underground supply and drain lines before the slab is poured — precisely located for every fixture in the design. This is the foundation of the entire plumbing system, and we get it right.
Above-Ground Rough-In
Once framing is complete, we run all supply, drain, and vent lines through walls and floors, stubbing out at each fixture location. Work is inspected and approved before drywall closes.
Solar Water Heater Rough-In
Hawaii law requires solar water heating on most new residential construction. We install the solar water heater rough-in and backup element connections as part of our new construction scope.
Fixture Installation
Final plumbing — sinks, faucets, toilets, showers, tubs, water heaters, and all appliance connections — installed correctly and tested before the Certificate of Occupancy inspection.
ADU Plumbing
Accessory Dwelling Units require full plumbing systems — often including septic system upgrades or new connections. We handle the full scope of ADU plumbing from permits through inspection.
Permits & Inspections
We pull all required plumbing permits, schedule inspections at each stage, and ensure every rough-in and finish inspection passes so your project stays on schedule.
Common Questions
Frequently Asked Questions
When should I involve a plumber in the new construction process?
Before finalizing the design if possible. Early plumber involvement prevents expensive changes — things like floor plan layouts that make plumbing runs unnecessarily complex or costly, or fixture placements that conflict with structural elements. We can review plans and advise before groundbreaking.
Does Hawaii require solar water heaters on new homes?
Yes. Hawaii Revised Statutes require solar water heaters on most new single-family residential construction. There are exceptions for structural or shading constraints that must be documented. As part of our new construction scope, we include the solar water heater rough-in and installation. See our water heater services for more detail.
Do new ADUs need their own septic or sewer connection?
It depends on the property. If your existing home is on city sewer, the ADU can typically connect to the existing line if the capacity is sufficient. If you're on a septic system, adding an ADU increases wastewater load and may require upgrading or expanding the system. We assess this during the planning phase.
How long does rough-in plumbing take for a new home?
Underground rough-in for a typical single-family home takes 2–3 days. Above-ground rough-in takes 3–5 days depending on the complexity of the layout. Finish plumbing (fixture installation) takes 1–2 days. We coordinate with your project manager to align with the overall construction schedule.
Can you work with my general contractor?
Yes — we work with GCs regularly and are used to coordinating with other trades. We communicate clearly about rough-in requirements, inspection hold points, and scheduling needs so your project doesn't experience plumbing delays.
Building on O'ahu? Start with the Right Plumber.
New construction plumbing done right from the start. Call Alpha Omega for a preconstruction estimate on your O'ahu project.