This article is the conversation we would have if you called us today for a quote. It is written for homes in Spain, so it refers to Spanish regulations and prices.
The question almost nobody asks first: can your contracted power cope?
Before looking at chargers, look at the meter. Most homes in Madrid have a contracted power of between 3.45 and 4.6 kW. A standard home charger draws between 3.7 and 7.4 kW while it is running.
The maths is simple: if you have 4.6 kW contracted, the oven on and the air conditioning running, there is no headroom left to charge the car without tripping the main switch.
There are three ways to solve it. The first is to increase your contracted power, which is usually the easiest option but raises the fixed part of your bill every month. The second is to install a charger with dynamic load management: a device that adjusts the charger's power in real time according to what the rest of the house is using. The third is to charge only during off-peak hours, when household consumption is at its lowest.
We tend to recommend the second option to almost everyone. It costs a little more to install, but it avoids a permanent rise in your fixed bill and means you don't have to think about what else is switched on.
Where to put it: far more important than it seems
In a detached house it is straightforward: the garage is yours, so you decide. Even so, there are two things to consider. First, the distance between the consumer unit and the spot where the charger will go — every extra metre of cable adds cost and, over long runs, efficiency losses. Second, the type of cable route: surface-mounted in trunking, recessed into the wall, or across the ceiling. The final finish varies a great deal depending on how this is done.
In a residential community it is more complicated, but not impossible. Spain's Horizontal Property Act gives you the right to install a charging point in your parking space without needing approval at a residents' meeting. You simply have to notify the building administrator. The installation runs from your own meter, so you pay for the electricity you use.
What does take judgement is the cable route from your meter to your space. In a shared garage, that cable may have to run for tens of metres and pass through communal areas. A good installer plans the route to be as short and clean as possible, not whatever happens to be convenient.
The actual installation: what happens on the day the technician arrives
A well-done installation in a standard home takes between three and five hours. These are the steps:
First, check the existing installation: consumer unit, residual current device, circuit breakers. If anything does not comply with regulations, it has to be fixed before anything is installed. That is not negotiable. If needed, we quote for it separately before we start.
Second, run the cable from the consumer unit to where the charger will go. This is where you see the difference between professional and amateur work: if the cable is left on show in badly aligned trunking, you will notice the poor installation every time you park.
Third, mount the charger on the wall, connect it and configure it. Configuration is the step where most mistakes happen — a badly configured charger can seem to work fine while charging at 50% of its real power, or cause random tripping that the user can't make sense of.
Fourth, test under real load. With the car plugged in, check that the current reaching it is what it should be. If you have dynamic load management, simulate several scenarios (air conditioning on, oven running) to make sure the charger adjusts correctly.
Fifth, explain everything to the customer. How to switch it on, how to pause it, what each indicator means, what to do if something goes wrong. This step is skipped more often than it should be.
The paperwork you should be given (and often aren't)
A home charging point installation produces two mandatory documents:
The CIE (Electrical Installation Certificate), signed by an installer authorised in the Especialista category under the REBT (Spanish low-voltage regulations). This is the document that legalises the installation with the authorities. Without it, your electricity company may refuse to change your tariff or require you to legalise the installation afterwards, at extra cost.
A written warranty on labour and installation. Búfala Tech, for example, offers 24 months on the installation, and the charger we supply carries the three-year legal guarantee. If your installer gives you nothing in writing, you have a problem the day something goes wrong.
It is also worth asking for the charger manual, the technical data sheets for the installed components and a photo of the modified consumer unit. None of this is mandatory, but a good installer hands it over without being asked.
How much does it really cost?
It is the most common question and the hardest to answer in writing, because it depends on three things: the charger you choose, how complex the installation is and whether you live in a residential community.
An honest range: in a detached house with a standard installation, most projects come in at between €1,200 and €2,500 all-inclusive (a well-known charger brand, full installation, paperwork and VAT). In a residential community with a long cable run, it can rise to €2,500–4,000.
Be wary of quotes under €800 that include "everything". It usually means a charger of doubtful quality, an installation without power management, or both. And then comes the surprise the first day the residual current device trips.
Five questions to ask before you hire anyone
Whether it's us or another installer, these five questions give you a clear picture:
One. Are you registered as authorised installers in the Especialista category under the REBT?
Two. Do you sign the CIE yourselves, or do I have to arrange it myself?
Three. Which charger brand and model do you recommend, and why that one?
Four. Does the installation include dynamic load management, or will I need to increase my contracted power?
Five. What warranty do you give on labour and installation?
A serious installer answers all five without hesitation. If any answer is vague or evasive, get a second opinion.