What To Know About In-Ground Hot Tubs

Nothing says “luxury” like a hot tub, and building one into the ground adds an exclamation point.

Currently there are 7.3 million hot tubs in operation in the United States, according to data from the Pool and Hot Tub Alliance. That’s more than double the number reported by the Los Angeles Times in 1996.

This increase in popularity signals the hot tub’s transition from a novelty to a relatively common fixture in modern neighborhoods. The surge owes much to the COVID-19 pandemic, when travel was limited and homeowners needed relief from lockdown blues.

California, where I live, is the nation’s hot tub capital, and I’ve seen my share of in-ground and above-ground ones. Part of my daily routine includes a visit to the in-ground tub at the local health club. And whenever I need to truly escape reality, I pop next door to soak in the wooden tub my neighbor built into his deck.

So many of my friends have above-ground and built-in tubs that the novelty has worn off a bit. But there’s still no better way to spend a chilly winter evening.

In-ground hot tubs aren’t as common around here as above-ground ones, for the obvious reason — they’re more expensive to install. Some with in-ground tubs made the extra effort to create a true oasis with stone liners, atmospheric pool lights and plenty of surrounding greenery.

What Is An In-Ground Hot Tub?

Build a waterproof container that can hold three or four people, fill it with hot water, and you’ve got a hot tub. It isn’t complicated. You can set it above ground on a foundation, bury it with the rim at ground level, or partially bury it to make it half-sunken.

You could conceivably drain your tub after every use and refill it before the next one, like a bathtub. But it’s more convenient, and less wasteful, to keep the water hot and clean. That’s where complications arise.

The tub needs water intake and output ports, a filtration system, and pipes to connect everything together. When you sink a hot tub into the ground, the hole must be big enough to accommodate all this plumbing. And you need panels or trap doors to access it so you can make repairs.

In-ground hot tubs can be made of concrete, stone, tile, gunite (sprayed concrete — a common pool liner material) or acrylic. They typically include a deck around them to make it easier to get in and out. Some even have stairs, and many contemporary ones also have hydrotherapy jets. Get to know if your deck is the right spot for a new hot tub with help from industry experts.

Concrete and stone tubs usually feature flat bottoms with ledges for sitting, while acrylic ones often come with molded bottoms with strategically placed jets for a relaxing water massage. The jets, as well as the heater and filtration pump, draw a lot of power, so most in-ground tubs operate on 240-volt circuits. If you can generate that electricity from solar panels, so much the better.

In-ground hot tubs are similar in some ways to in-ground swimming pools. You maintain the water the same way, balancing pH and sanitizer levels to keep it safe and clean. But instead of chlorine, many hot tub manufacturers recommend bromine for sanitizing because it’s gentler and lasts longer. Here are our favorite hot tub shelter ideas for a cozy outdoor experience.

You can also drop a pre-made hot tub into the ground rather than building it from scratch. You don’t have the pre-manufactured option with a swimming pool.

In-Ground Hot Tub Pros and Cons

If you’re in the market for a new hot tub, here are some pros and cons of in-ground tubs to help you decide (you should also consider these hot tub accessories to go along with your purchase):

Pros

• Unobtrusive: A sunken hot tub has a minimal impact on the landscape design. It’s as easy to incorporate it into a garden as a patio or deck, and won’t affect the sight line.
• Permanent: Like an in-ground swimming pool, a sunken hot tub becomes an integral part of the property, often raising the resale value of the home.
• Accessible: Climbing into an above-ground hot tub can be a chore for some. Anyone who can crouch down and sit on the deck can easily get into a sunken tub.
• Energy efficient: Because the ground provides thermal insulation, it costs less to keep the water hot.

Cons

• Expensive: It costs more to install than an above-ground tub. Repairs are also more costly because of limited access to the plumbing.
• More vulnerable to debris: Because the lip is at ground level, it’s easier for leaves and other debris to blow in, so it needs more frequent cleaning.
• Difficult to cover: Custom-built in-ground hot tubs need custom covers. Because the cover is at ground level, it can be inadvertently displaced.
• Permanent: You can’t take it with you when you move.

How Much Does an In-Ground Hot Tub Cost?

Compared to an above-ground hot tub, a sunken one is a major investment. Expect to pay $5,000 to $25,000 or more, depending on the size of the tub and the type of material. An above-ground tub runs from $3,000 to $12,000.

You may opt to buy an above-ground tub, then have it sunken or partially sunken into the ground. If so, you’ll pay from $3,000 to $5,000 for excavation and installation, along with the cost of the tub itself.

In-Ground Hot Tub Installation

Installation of a factory-made in-ground tub calls for planning and preparation. Go to www.call811.com to get necessary underground utilities marked, choose a suitable location, get building permits and excavate.

After excavation, you need to install a drain with plumbing and construct a foundation that can support the tub. Finally, there’s the installation of plumbing and electrical circuits for the tub equipment, often positioned in a nearby outbuilding.

When the tub arrives, it needs to be positioned in the hole, which usually requires a crane. Then a professional installer connects the plumbing and completes the electrical hookups.

Once all that work is done, fill the tub with water and check out the operation of the equipment. Now you’re ready to add sanitizers and start enjoying your new backyard retreat space. Looking for more? Here are our favorite backyard hot tub privacy ideas.