[Kirby]

I have been lurking here for a while and am genuinely impressed by the level of knowledge and helpfulness that I have seen.

My situation is that I have my first BEV (VW ID.3) on order and have started the process of having the charging point installed in my garage. There is a distribution box there with a light and a couple of sockets. I have recently discovered that when the developers built the house in 2013 the garage was not added as a separate circuit but seems to be on the same circuit as the ground floor sockets.
I would appreciate any advice on the consequences of this and suggestions for a safe and easy charger installation.
I have included photos of the distribution unit in the garage, the main fuse box and the meter if that is useful.

 

[Harry6]

Very unusual to have it of an existing circuit as it looks like it is a separate DB.
I would hope your charger installer would sort it out for you.

 

[Jeremy Harris]

Not uncommon to have a garage as a spur off the ground floor ring final, our last house originally had that arrangement, put in by the builder.

Your new charge point ideally needs to be connected into the tails using a small connection box, to provide a dedicated supply that's properly protected. Looks to be straight forward enough from the photos to do this. You might be asked to get an isolator switch installed before hand, and some suppliers will do this free of charge, some charge for it and some just tell you to get your own electrician to do it.

 

[Hitstirrer]

Much depends on the location of the various parts in this chain of supply. A sketch plan, with dimensions, of where the meter, house CU and garage CU are in relation to each other can greatly affect suggestions on how to proceed. The main company fuse holder is rated at 100 amps which is a good start but does not guarantee that it actually has a 100 amp fuse inside. As the house CU already has quite a few 32 amp outlets and one 40 amp for the shower the calculation to sanction another 32 amp car charger unit may be an issue. There are ways around this of course but whatever happens it is highly likely that a new cable will need to be run directly from the house side of the meter to the garage to replace the existing garage supply. This is why the 'geography' matters as the routing and distance will be critical.

 

[Kirby]

All sounds reasonably achievable. Terraced house with meter and main fuse box at front, garden (7m long) at rear and then garage behind that.

 

[Hitstirrer]

OK - but another couple of questions. You say 'terraced'. Is this house end of terrace with an outside wall at one end that can route an armoured cable? And is there a sturdy 7m fence at the garden end where a cable can be attached? Or is there evidence of a conduit from garage to house with a possibility of pulling a new cable through rather than have to route it around the house? In extreme circumstances sometimes a new cable has to go up the wall at the front then through the loft and back down at the rear. Then trenched across the garden. Hope this isn't needed.

 

[Kirby]

Not end of terrace, houses on both sides so no external wall. There is a conduit carrying the cable from the house to the garage that might be able to take another cable pulled through. Feels like it's getting more complicated. Why is the cable up the wall, through the loft and down the back wall not desirable, is it just cost? Or is there a practical reason to not do it?

 

[Hitstirrer]

Not end of terrace, houses on both sides so no external wall. There is a conduit carrying the cable from the house to the garage that might be able to take another cable pulled through. Feels like it's getting more complicated. Why is the cable up the wall, through the loft and down the back wall not desirable, is it just cost? Or is there a practical reason to not do it?

If there is a conduit that's good news for that part of the route as the old cable can usually be used to pull a heavier duty cable through. Of course, the existing cable might be already suitable to carry the load and not need a higher duty cable into the garage.

It's just cost really if a new cable has to be routed over the house. Both in extra cable and extra manpower and time to do that. Many people undertake that physical part themselves to save a bit of money. If that same cable can then be pulled through the existing conduit then happy days.

But best to wait for proper advice from a charge point fitter as they will be able to properly assess the whole installation. But the message is that all things are possible. Just some installations cost more than others. And even if the electrician pulls a face at the new total load there are electrical gizmos that can limit total draw to the house in cases like the car being plugged in when someone is taking a shower and the cooker is on as well as the kettle, TV and lights. Those witchcraft gizmos can lower the car charge in such instances to keep the total house draw below the company fuse rating.

 

[Redimp52]

Not end of terrace, houses on both sides so no external wall. There is a conduit carrying the cable from the house to the garage that might be able to take another cable pulled through. Feels like it's getting more complicated. Why is the cable up the wall, through the loft and down the back wall not desirable, is it just cost? Or is there a practical reason to not do it?

Your setup looks identical to what I have, mid terrace 20m+ from consumer unit to the charger location, electric already in the garage (although mine was a separate circuit). I couldn't use the garage circuit as it couldn't support a 7kW charger and the route for the wiring went under the patio and garden so upgrading it would have been expensive. In the end the electrician ran a new circuit through the house in trunking under the stairs, through one internal wall and back out the rear of the house, then he had a route that allowed him to attach the cable above ground round the back garden before reaching the Zappi mounted on a post, anything else would have required earth works to reach the garage and cost even more than it did.
Your biggest problem will be getting someone to even look at it and discuss options, I tried about 10 companies, only about 5 even aknowledged the enquiry, 3 of those once I submitted the diagrams and photos online never answered again, one said not interested unless I dug up the patio to route a new cable. In the end I found a company with good reviews that actually spoke to me and discussed options (quoted for 3 different options).

 

[Hitstirrer]

That's the experience of a lot of people. Once a sparky realises that it involves a long run of cable to be routed through, round, or over a house they lose interest and go to cherry pick easier jobs. This is why a lot of people do the cable routing themselves and leave the sparky some free cable at both ends to just couple up. A lot of people also run into domestic strife if they disturb the internal walls by running unsightly trunking and causing redecoration work. Hence the unattractive route of up a wall, through a loft, and down again being often used. But in this case it may be acceptable to run under the stairs and trunk to the back, then along the wall to where the existing conduit can be used to go under the garden. If that can be carried out DIY style then perhaps an electrician can be tempted to pay attention.

 

[Kirby]

Many thanks for your help, I feel better informed and will be better armed when discussing this with electricians now.