I want to build a hot tub – where do I start?

I want to build a hot tub - where do I start

I want to build a hot tub – where do I start? If this is you then read on. In this article I will try and give you all the information you need to think about if you want to build a hot tub but do not know where to start.

The Location


If you want to build a hot tub then the first thing you need to decide on should be the location. Quite often, in your property there is an “obvious” location. Either, there is a place with a. view, or perhaps there is only one place that you can site you new tub.


Either way, you need to make sure the location is going to work for you. Think about the tub, the orientation, the location of the control room (see below) Where is your water source (how are you going to fill it up) Where are your drains (for when you want to empty it) All of these things you need to think about for the location.


Don’t forget the control room.


If you want to build a hot tub, then you need to have a control room. On this blog and on my YouTube Channel I talk a lot about the control room placement and how important that it. Make sure you leave enough space when you are thinking about building your tub and looking at the location.



The Size & Shape


Size and shape are important. Complicated shapes are going to be more difficult to build. Larger tubs are going to take more time to heat up and will have a larger running cost.


Think about the size and also think about the volume of water that is going to be in the tub. It is always a good idea to check against some of the plastic shell tubs that you can see on the market. This will give you an indication if you are going to be “too big”.


To help you out here, the average tub size that my customers are building at the moment is 8’ x 8’ – some are bigger and some are smaller but this can help give you a starting point if you are struggling to get started with your hot tub project.


The Construction Type


The construction method that you choose is going to be important. What are your skills? Are you more of a timber kind of a person than a brick layer? If so, then forming might be for you. If you can lay blocks – then this is an obvious choice.


Then, there is always the “slightly left field” way of doing things with the ever increasing in popularity ICF blocks like TubBlox. With the insulation already there for you and a super easy method of putting the form together – ICF blocks are becoming more and more popular.


Electrical Planning


A hot tub typically requires a dedicated 240V/50A electrical circuit with a GFCI (ground-fault circuit interrupter) protection. This means that the electrical service to the hot tub must be a separate circuit from other electrical devices in the home, and the circuit must be protected by a GFCI device to prevent electrical shock.


It is important to consult with a licensed electrician to ensure that the electrical service to the hot tub meets all local codes and regulations and that the wiring is properly installed and grounded.


230V I hear you say, we don’t have this in the USA – you do. Generally coming into your home you have 2 x 115V inputs. An electrician can wire these for you to give you the voltage you need.


To get 230V from a split system, you would need to use the L1 and L2 wires to provide the voltage. The L1 and L2 wires are the two hot wires that provide the voltage for the split system.


In a 230V circuit, L1 and L2 are connected to opposite legs of the electrical service, with L1 typically providing 120V and L2 providing the other 110-120V for a total of 230V. It’s important to consult with a licensed electrician to ensure that the circuit is properly wired, grounded, and in compliance with the local electrical codes and regulations before connecting the split system


We need a higher voltage as that reduces the current draw and makes it safer to use. I have a much more in depth article here on hot tub electrics.


Heating Method


There are several heating options available for DIY hot tubs, including:


  1. Electric heating: This is the most common option for DIY hot tubs as it is relatively simple to install and maintain. Electric heating elements are found inside pretty much every Spa Pack on the market so it is simple but can be slow and expensive to use.
  2. Gas heating: This option uses a gas-fired boiler or a gas-fired heater to heat the water in the hot tub. This option is more expensive than electric heating, but it can heat the water more quickly and is more energy-efficient.

  1. Solar heating: This option uses solar panels to collect energy from the sun and transfer it to the hot tub to heat the water. This is a more environmentally friendly option, but it may not be as efficient in areas with limited sunlight.
  2. Wood-fired heating: This option uses a wood-fired stove or a wood-fired heater to heat the water in the hot tub. This is a more rustic and traditional option, but it can be more labor intensive and may not be as efficient as other options.
  3. Air Source Heat Pump – certainly my favourite option at the moment.

An air source heat pump (ASHP) can be a good option for heating a hot tub, as it is a relatively energy-efficient way to heat the water. ASHPs work by absorbing heat from the air outside and transferring it to the water in the hot tub. They have the advantage of not requiring a separate fuel source like gas or electricity, just electricity to run the compressor and fan.


However, there are some things to consider before choosing an ASHP as a heating option for a hot tub:


  1. Climate: ASHPs are less efficient in colder temperatures, so they may not be the best option in areas with severe winters.
  2. Size: The size of the ASHP will depend on the size of the hot tub, so it’s important to ensure that the unit is large enough to heat the water efficiently.
  3. Cost: ASHPs can be a more expensive initial outlay than other heating options, so it’s important to consider the initial and ongoing costs before making a decision.


Features, Jets and More


It is possible to add a water feature to your hot tub. Some popular water feature options include waterfalls, fountains, and water jets with lighting. You do need to have a good think about what you are going to add and how you are going to do it.


It is not something you want to add afterwards as a water feature may affect the electrical and plumbing systems of the hot tub. Additionally, the type of water feature that can be added to your hot tub will depend on the design and construction of the hot tub.


My Plans and Designs are Great way to Get Started with your DIY Hot Tub.


In My Online Store, I have a huge amount a ready-made designs and plans for you to use. This is a great way of getting started.


All of these plans come with multiple plumbing layouts, they come with access to my video course and all include the Ultimate DIY Guide as standard. Huge amounts of value and a great way to start your DIY Hot Tub Project.

Can I Help You?

If I can help you in any way I would love to hear from you. You can get in touch using the form below.

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.

Today, I've helped over 1000 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

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