Should You Add a Hot Tub or Spa to Your Pool? Pros, Cons & Costs

Adding a hot tub or spa to an existing pool is one of the most requested upgrades we handle here at Top Knox Pools. And for good reason when done right, a pool and spa combo can dramatically elevate your outdoor living experience while adding real value to your home. But it's not without trade-offs, and the costs can vary widely depending on how you approach the project.

In this guide, we'll walk you through everything you need to know before making the decision from the practical benefits and potential drawbacks to real cost ranges and what the process actually looks like for homeowners across Knoxville, Maryville, Farragut, Oak Ridge, and the surrounding East Tennessee area.

What Is a Pool and Spa Combo, Exactly?

A pool-spa combo (sometimes called a "spool" when the two are blended into a single vessel) refers to an integrated design where a hot tub or spa is attached to — or built alongside — your swimming pool. There are three main configurations:

• Attached spillover spa: The most popular option. The spa sits elevated above the pool and water cascades down into it, serving as both a feature and a heating element.

• In-pool spa: The spa is built directly within the pool shell, separated by a raised edge or bench — no separate structure required.

• Freestanding spa addition: A separate hot tub installed near (but not connected to) an existing pool. The most budget-friendly integration, though not truly a combo.

The Pros of Adding a Hot Tub or Spa to Your Pool

1. Year-Round Use in Tennessee's Climate

Let's be honest — Tennessee winters are mild but real. A standalone pool in Knoxville typically sits unused from November through March. A spa changes that math entirely. You get 12-month outdoor living potential, not five or six months. For many homeowners, that alone justifies the investment.

2. Increased Home Value

According to the National Association of Realtors, outdoor amenities — including pools and spas — can return 50–80% of their cost in added home value, particularly in warmer climates and desirable neighborhoods. In competitive East Tennessee markets like Farragut or West Knoxville, a high-end pool and spa combo can be a meaningful differentiator when it's time to sell.

3. Hydrotherapy and Wellness Benefits

Hot tubs aren't just a luxury — they're used therapeutically for muscle recovery, joint pain, stress reduction, and improved sleep. The Arthritis Foundation endorses warm-water therapy as a legitimate tool for managing chronic pain. If you or anyone in your household deals with back pain, athletic recovery, or general stress, a spa could deliver tangible health returns.

4. Stunning Aesthetic and Entertainment Appeal

A spillover spa adds a dramatic visual element — flowing water, ambient lighting, and an architectural focal point that elevates the entire backyard. For homeowners who love hosting, it's a natural gathering spot and a guaranteed conversation starter.

The Cons You Need to Know Before Committing

1. Higher Upfront Cost

There's no getting around it — adding a spa to a pool project (or retrofitting one onto an existing pool) adds significant cost. If you're building new, an integrated spa typically adds $15,000–$30,000+ to your total project budget. A retrofit on an existing pool is often more complex and can run higher depending on plumbing access and the scope of decking work required.

2. Higher Ongoing Operating Costs

A heated spa uses more electricity and gas than a pool alone. Depending on how often you use it and how well insulated your system is, expect your utility bills to increase — potentially $50–$150 per month. A well-designed system with a good cover and programmable heating schedule can minimize this, but it's a real ongoing expense to plan for.

3. More Complex Maintenance

Spas require more frequent water chemistry management than pools — the smaller water volume and high heat mean chemical imbalances happen faster. If you're not prepared for that routine (or willing to hire a pool service company to manage it), the spa can become a maintenance headache.

4. Space Constraints

Not every yard is suited for a spa addition. If you're working with a compact backyard in a neighborhood like Bearden or Sequoyah Hills, a full spillover spa may not be feasible without careful planning and design. An in-pool spa or compact plunge-style spa may be better alternatives in those cases.

What Does It Cost to Add a Hot Tub or Spa to Your Pool?

Cost is the number one question we hear from homeowners across the Knoxville area. Here's a transparent breakdown of what you can expect in 2024–2025, based on projects Top Knox Pools has completed across East Tennessee:

Spa Type / Scope	Cost Range	Notes
New Build – Integrated Spillover Spa	$15,000–$30,000+	Added to new pool construction
Retrofit – Adding Spa to Existing Pool	$18,000–$40,000+	Depends on plumbing access & decking
In-Pool Spa (new construction)	$10,000–$20,000	Simpler; within the pool shell
Freestanding Hot Tub Near Pool	$5,000–$15,000	Least invasive; no plumbing tie-in
Monthly Operating Cost (estimate)	$50–$150/mo	Varies by use, insulation & rates

Important note: These figures reflect general market ranges and typical project scopes in the Knoxville, TN area. Your actual cost will depend on yard access, existing plumbing, the spa's size and features, and the finish materials you choose. The only way to get an accurate number is through an on-site consultation which is exactly what we offer.

💧 Get a Free Cost Estimate for Your Knoxville Pool Spa ProjectReady to find out what a spa addition would actually cost for your yard and your budget? Call Top Knox Pools today at (865) 335-8047to schedule your free, no-obligation on-site consultation. We serve Knoxville, Maryville, Farragut, Oak Ridge, Lenoir City, and all of East Tennessee.

Should You Add a Spa to Your Existing Pool or Build One New?

This is one of the most nuanced questions we work through with homeowners. Here's a quick framework to help you think it through:

• Build new if: you're planning a pool renovation or starting from scratch — integrating a spa from the beginning is almost always more cost-effective and design-cohesive than retrofitting later.

• Retrofit if: your existing pool has accessible plumbing and your deck has room for a natural extension this is doable and done regularly, but budget more time and money than a new build.

• Consider freestanding if: your budget is tight or your yard layout doesn't accommodate a built-in spa a quality portable hot tub near the pool still delivers many of the wellness and entertainment benefits.

Quick Answers to Common Pool Spa Questions

Can I add a hot tub to my existing inground pool?

Yes — in most cases. The feasibility depends on your existing plumbing, available space, and structural considerations. A site visit from an experienced pool contractor (like Top Knox Pools) is the fastest way to determine what's possible for your property.

Do pool spas require separate permits in Tennessee?

Yes. In Knox County and surrounding municipalities, adding a spa to a pool or building a new pool-spa combo requires a building permit. Top Knox Pools handles the permitting process for all of our clients — it's included in our project management.

How long does it take to add a spa to a pool?

A new integrated spa on a pool build typically adds 1–3 weeks to the project timeline. A retrofit — depending on complexity can take anywhere from 2 to 6 weeks once construction begins. Planning and permitting add time on the front end, so starting the conversation early is always advisable.

Why East Tennessee Homeowners Choose Top Knox Pools

Top Knox Pools isn't just another pool company. We're a locally rooted team that has designed and built custom pools and spa combinations across Knoxville, Maryville, Farragut, Oak Ridge, Lenoir City, and throughout East Tennessee for years. We know this region's soil, its climate, and — most importantly — what East Tennessee homeowners actually want from their outdoor spaces.

When one of our clients in Farragut came to us wanting to transform their dated 1990s pool into a resort-style backyard, we designed a raised spillover spa with LED lighting and a natural stone surround. The result? A complete outdoor transformation and a neighbor who called us the next week to inquire about their own project.

That kind of word-of-mouth trust is what we build on. Our process is transparent: we walk you through options that fit your yard, your lifestyle, and your budget not just the most expensive upgrade we can sell.

The Bottom Line: Is a Pool Spa Combo Worth It?

For most East Tennessee homeowners who use their pool regularly and want to extend their outdoor season, the answer is yes adding a hot tub or spa to your pool is worth serious consideration. The key is going in with clear expectations about cost, maintenance, and what type of spa actually fits your yard and lifestyle.

The worst thing you can do is make a decision based on a magazine photo or a general price estimate from the internet. Every backyard is different. Every budget is different. And every family uses their outdoor space differently.

That's why we always start with a conversation not a sales pitch. Top Knox Pools has helped hundreds of Knoxville-area families build outdoor spaces they actually love. We'd be glad to help you figure out if a pool and spa combo is the right move for yours.

Ready to Transform Your Backyard?Call Top Knox Pools at (865) 335-8047or visit our website to schedule your FREE consultation today.Serving Knoxville, Farragut, Maryville, Oak Ridge, Lenoir City & all of East Tennessee.