Oasis Pools
Design

Raised Spas and Spillovers: Designing the Spa Into the Pool

·3 min read·Oasis Pools

An attached spa is the most requested addition on the pools we design, and the question that follows is always the same: raised or flush? The answer shapes the whole look of the pool, the plumbing behind it and, more than people expect, how often the spa gets used. Here is how we think about it.

Flush spa

A flush spa sits at the same level as the pool, separated by a dam wall just below the waterline. It is the cleanest, most modern look, and it makes the pool feel bigger because the water reads as one surface. Structurally it is the simplest, which keeps cost down. The tradeoff is that the spa does not announce itself; from the house it looks like part of the pool, and there is no spillover to hear or see.

Raised spa

A raised spa sits above the pool, usually with the spa wall facing the pool finished in tile or stone. The wall doubles as a bench inside the pool, which is one of the most used features in the whole yard. The height gives the spa presence from the house and the patio. Raised spas need steps up from the deck, a structural wall and more finish material, so they cost more, and they need a bit more thought about where people climb in and out.

The spillover

A spillover is water flowing from the raised spa over its wall into the pool. It can be a smooth sheet over a single wide edge, a series of scuppers, or a rough stone cascade. It gives the pool a water feature without a separate structure, and the sound is one of the main reasons people choose a raised spa in the first place. If you are sensitive to sound, our post on water feature noise is worth a read, because a sheet spillover and a stone cascade sound very different.

The spillover runs off the pool's circulation, not the spa's heater. When the spa is being used, a valve isolates it so the heater is not warming water that then flows into the pool. On an automated system this is a button; on a manual system it is a valve at the equipment pad.

Plumbing and heat

An attached spa shares the pump, filter and heater with the pool, with valves that switch between pool mode, spa mode and spillover mode. The spa also has a blower or a dedicated jet pump for the jets. Heater sizing matters here: a spa needs to come up to temperature in a reasonable time, and a heater sized only for the pool will feel slow. Sizing a pool heater explains the math. A gas heater is the usual choice for spa use because it heats fast; a heat pump is efficient for the pool but slow for the spa.

Where the spa goes

The best spot is close to the house and the patio, on the path from the back door, so getting to it on a cool evening is a few steps rather than a walk across a wet deck. It should be in the sightline from the main indoor room, and ideally sheltered from the prevailing wind. On a sloped Piedmont lot, a raised spa at the uphill end of the pool often solves a grading problem and looks intentional doing it; building on a slope covers that layout.

Attached vs stand-alone

A portable or stand-alone spa next to the pool costs less, heats faster because it holds heat under a cover, and can be added any time. An attached spa looks like part of the design, shares equipment and gives you the spillover and the bench. If the spa will be used year round and the pool is closed in winter, a stand-alone with a good cover is more efficient. If the look and the integration matter, attached wins. Hot tubs and spas for NC homeowners goes deeper on that choice.

Details we decide up front

We build attached spas as part of custom pools across the Triad, including Jamestown and Lewisville. Ask for a free consultation and we will sketch how a spa fits the yard before anything is committed.

Frequently Asked Questions

Does a spillover spa waste heat?When the spillover is running, warm spa water flows into the pool and cools. That is why the spillover is usually on its own valve or automation setting, so it runs for the look during the day and is shut off when the spa is being heated for use.
How high should a raised spa be?High enough to act as a seat from the pool side, roughly bench height, is the most common. Higher looks dramatic but adds structure, steps and cost, and a spa you have to climb into gets used less.
Can a spa be added to an existing pool?Yes, as a renovation, though it means new plumbing, a heater sized for it and usually a new equipment layout. A stand-alone spa next to the pool is simpler to add later than an attached one.
Is a raised spa harder to maintain?Slightly. It has its own surface to brush, its own jets and drains, and the spillover wall collects scale at the waterline. None of it is difficult, but it is more surface area.

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Oasis Pools builds custom pools and outdoor living spaces across High Point, Greensboro, Winston-Salem and the Triad. Tell us about your yard and we'll put together a free, no-pressure consultation.