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The shower problem can be easily solved with a priority box, that works by only allowing one of the two showers to be on at any one time. You can either get a priority box set so that one shower takes precedence, or one that works on a first come, first served, basis. The most popular shower priority box is probably the Garo one, and they do one specifically to allow two showers and an EV charge point to operate from a current limited supply: Garo 1 Row 2 Showers 63A EV Charger Priority Distribution Board / Consumer Unit

Alternatively, you could opt for a charge point that has load limiting, although I think that you're already way over the maximum load with just the two showers and other stuff. An another option might be to look at fixing the shower problem with a shower priority box, then fitting a load limiting charge point.

There are lots of options to be able to install several high load devices safely, such that there is no risk of the supply being accidentally overloaded, just needs an installer that understands how best to make that happen for your installation.
 

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The issue is one of not relying on behaviour to prevent a circuit overload. Whilst some would be quite OK about modifying their behaviour so as to always keep the load within limits, others may well not be. For that reason the regs require that the risk of overload be mitigated in such a way that it doesn't matter what a consumer does, they cannot cause the installation to exceed it's rated current capability.

A priority box removes the need to remove one of the showers - it mitigates the overload risk by only allowing one to operate at a time. The basic shower priority box (without the EV capability) is this one: Garo 1 Row Shower Priority Metal Board | Express Electrical

I would advise trying to find a good local electrician that understands how to best design and install load limiting kit. It's not rocket science, but also not something that some of the big EV installers will really want to be bothered with - they very much work on the basis of making the EV charge point installation as simple for them, even if it means making things less convenient for the customer.
 

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Really you need two priority boxes or a charge point that will manage its load based on overall usage.
You can get a non-priority box that can control three loads: Garo 1 Row 3 Showers 40A EV Charger Non-Priority Distribution Board / Consumer Unit

This allows whichever of three loads comes on first to take priority over the other two loads. In practice this works fine for things like EV charging, when it's not likely that a car will be charging at the same time as other high current loads are in use.
 

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Just want to be thankful you don't live in France, or one of the other countries that have load-dependent tariffs. The "normal" supply in France is 6 kVA for a standard domestic tariff, and to enforce that EDF fit a disjoncteur différentiel to the incoming supply that trips the whole installation out if the tariff limit is exceeded. If you want to install a 32 A charge point you need to pay out for one of the higher tariffs, when EDF will then fit a higher rated disjoncteur différentiel to alloe a higher current to be drawn from their supply.
 

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Hi, Sorry for the delay as I was away for work. There isn't a box on the outside, only a black thick cable coming out of the ground and up the wall of the garage and through the wall at the top where it comes out inside. I will probably get a couple of survey / quotes done for any extra work needed, thank you.
The crimps are in this photo, and I very definitely would not want to run 32 A through these for hours on end:

Circuit component Hardware programmer Electronic engineering Electronic instrument Electronic component
 
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