Hot Tub Control Room Design: Distance, Height, Size and Layout

Last updated: September 2026

The control room is the brains of your DIY hot tub. It’s the room or space where you house the pumps, blowers, spa pack, dosing kit, heater and every other external component. Without it, your hot tub would just be a tub.

There’s a lot to think about when you design one, so here’s what matters: distance, elevation, size, services and maintenance.

The distance

For a DIY hot tub, keep the control room as close to the tub as you can. The shorter the pipe run, the higher the pressure and the more power you get at the jets. I recommend keeping it within 15 to 20 feet (4.5 to 6m) of the tub.

Go further and standard blowers can struggle, and you may lose jet power from the pump unless you make design changes. Larger distances can be done, but they need bigger pumps, sometimes bigger pipework, and heavier-duty equipment such as air blowers, so they cost more.

Elevation: where the control room sits relative to the water

The height of the control room relative to the waterline is one of the most important decisions you’ll make. Getting it wrong can lead to system failure and expensive corrections.

	Below the waterline (recommended)	Above the waterline
Pumps	Standard hot tub pumps, fed by gravity	Needs specialist self-priming pumps
Priming	Natural, because water flows to the pump	May need extra priming arrangements
Cost	Lower, because you use hot tub parts rather than pool equipment	Higher equipment cost
Strain on equipment	Reduced	Higher
When to use	Whenever the site allows	Only if site constraints force it

If your site forces the control room above the water, read using a priming circuit on a centrifugal pump and the self-priming pump options before you commit.

Test your elevation

1. Install temporary piping from the tub to the control room.
2. Open the valves with the pumps off.
3. Water should flow freely through the pipes.
4. If it flows on its own, your elevation works for standard hot tub equipment.

Control room size

I get asked a lot how big the control room should be. As large as your limits allow. The bigger it is, the easier it is to maintain, repair and upgrade later.

I made the mistake of building a small control room for my own hot tub, and it caused maintenance headaches. It was such a challenge that I remodelled a year later. You can see the new one in my hot tub control room remodel or in this video.

Suggested space requirements

Item	Space to allow
Each pump	1ft wide x 2ft long (about 300 x 600mm)
Each blower	Same as a pump
Spa pack	Same as a pump
Cartridge filter (50 sq ft)	1.5ft of vertical height (2ft or 600mm is better)
Heater	Varies, so check the specifications and plan accordingly

These are floor-space guides for each item. Add space to reach and service them, room for pipework and unions, and room for whatever you might add later, such as an air source heat pump or a circulation pump (how to add one).

Note: unlike swimming pool equipment, hot tub parts should be covered and protected, so don’t leave them exposed. Give the enclosure ventilation so heat from the heater, blower and spa pack can escape, and make sure the space can’t flood and stays frost-free where winters are cold.

Services

Electricity, water, gas or propane: whichever services you need must reach the control room, so check it’s feasible, especially in a rural location. Plan the cable route before you pour anything, and have the electrics installed by a qualified electrician. My guides to hot tub wiring and hot tub electrics explain what’s involved.

Maintenance

Finally, think about maintenance. Mostly that comes down to the size of the room, but it’s also about piping everything neatly and labelling it. Clear labels and valves and unions in the right places make future servicing much faster. Noisy equipment is another reason to plan space and insulation: noisy hot tub pump covers the causes.

A well-designed control room saves time and money through easier maintenance and less strain on the equipment. When in doubt, go larger than you need today so you can expand later.

Want the layout done for you?

My Ultimate Hot Tub Control Room Guide is a PDF with step-by-step instructions for building a control room setup (it’s a guide only, with no parts supplied). The control room layout and plumbing are also part of my DIY hot tub plans, and for a custom tub I can draw it up as part of an architectural CAD and 3D plumbing design. See also the control room post.

FAQs

How close should the control room be to the hot tub?

Ideally within 15 to 20 feet (4.5 to 6m). Longer runs lose flow and need bigger pumps, pipe and blowers.

Should the control room be above or below the water level?

Below is best. Standard hot tub pumps then prime naturally with gravity-fed water. Above the waterline you’ll need self-priming pumps and possibly extra priming arrangements.

How big should a hot tub control room be?

As big as you can make it. Allow roughly 1ft x 2ft for each pump, blower and spa pack, about 1.5 to 2ft of height for a cartridge filter, then add room to work and to expand.

Do I need to cover the equipment?

Yes. Hot tub parts aren’t designed to be left exposed to the weather like pool equipment. Keep the room ventilated, dry and frost-free.

What if my control room is too far from the tub?

You can do it, but you’ll need bigger pumps and often bigger pipework and heavier-duty blowers, so the cost goes up. It’s better to redesign the layout to bring it closer.

Got a question about your own build? Drop it in the comments below. I read them all.

Cheers,
Andi

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Thanks - Andi

 

Hi, Andi here. I own Buildahottub.com and also write all of the articles and info pages on the site. Some years back now, I built my own hot tub but struggled to find the information I needed. So, once my tub was complete, I started this website to help others in their own pursuit of hot tub and plunge pools DIY building information.

Fast forward to 2025, I've helped over 1400+ DIY customers just like you all over the world build hot tubs and pools. Have a good look around the site, there are lots of resources here. Please do get in touch if I can help you. - Cheers, Andi