In brief
A smart home in a residence starts with the cables in the walls, and those are laid once. Before anybody shows you an app, you have to sit down and settle what the house is supposed to do by itself and why, because everything else follows from that list – including the answer to whether you need a system at all. Some decisions are made together with the electrical design, and changing any of them after the plastering means chasing walls: how the cables are run, the space for the distribution boards and the equipment cabinet, power and control for the shading, the outdoor cable routes. I program this system myself, with you involved, and I care less about how much it can do than about whether you can change it later without calling anybody. The alarm stays separate, and below I explain the one point where it meets the automation.
What the house should do by itself
The electrical installation is my favourite stage of a build, and at the same time the hardest one for clients. To place the sockets and the switches you already have to know where the beds will stand, what the kitchen will look like and which lights should come on when you press a single button – with a year still to go before the finishing work. On a residence the same difficulty grows, because the house is supposed to do more things by itself, and behind every one of them there is a cable somebody has to lay before the plaster goes on. (The houses I build are masonry, and the cables run in the walls under the plaster, so a cable that was forgotten means cutting a channel into a finished wall.)
So before you even start talking about particular solutions, sit down and think about what you would like to automate in your house, and why. What problems do you mean to solve with it? What annoys you in everyday life, and which things could be automated because you do them regularly? The answers are usually simpler than the brochures suggest. If you often forget to switch the lights off when you go out, it would help if all of them went off by themselves once you had left. If you get up at night to go to the toilet, it would be good if the light in the corridor came on at 5% instead of full brightness when you press the button, so that you get to the bathroom safely without waking yourself up. The shading can come down by itself when the sun reaches the terrace, and the heating can know that the house is empty.
Automation does the most good when it takes a whole job off the household’s hands. A robot that cleans the whole house is excellent automation of that kind: it needs attention literally once every few weeks, because it washes its own mop in boiling water, fills itself from the mains and empties into the drain; it has a small station plumbed into the water supply and the drainage, so the floors are washed every day while nobody is at home. That station needs a water point and a drain in a particular place, and that is a decision for the plumbing design, not for the appliance catalogue. Added after the tiling, it goes wherever there happens to be a socket and a tap.
Everything else then follows from the list of functions: how many cables and of what kind, how big the boards have to be, and quite often the conclusion that no system is needed at all. For many people a smart home is a mistake. You need some interest in the technical side and a willingness to get involved, so that a house that does things by itself does not start getting in the way. For this conversation I have a checklist for clients – something like 400 questions – so that the client can tick what he wants and, above all, see what the options are and what is available at all. Very often the list that comes out of that conversation is shorter than the client expected, and that is a good result, not a failure. I am not saying such a system has no advantages – of course it has. But there is nothing wrong with preferring to switch the light on with an ordinary switch and having no need for scenes, scenarios or any other automation. When my wife and I were considering a smart home system, we came to the conclusion that the only thing we cared about was being able to control the external roller shutters.
The possibilities are enormous, and that is exactly why it takes broad knowledge and experience to configure the system so that it is comfortable to live with. An experienced installer is indispensable if the system is really to make your life easier, rather than leave you wondering how to turn on the light in the living room. That applies to anybody who sets up a system like this, me included: what counts is how many such installations you already have behind you.
The second thing I put before the electrics is the interior design. Planning a smart home system without an interior design is working in the dark, and because the cabling has to be run in a completely different way, alterations to the installation are much harder than with a standard electrical installation. That is why I commission the interior design at the very beginning; I have written separately about how the aesthetic decisions in a residence fall into place.
What is decided together with the electrics
An ordinary installation is simple: a cable runs from the board to the switch and from the switch to the lamp, the switch breaks the circuit, and that is the end of it. In an installation built for automation, the controlled points – lighting circuits, shading motors, selected sockets – usually each get their own cable, run straight back to the board or to a sub-board on that floor. The button on the wall no longer breaks the circuit itself; it sends a signal to a module or onto the bus, and what happens next is written in the program. It looks like a detail, which is why it gets overlooked, but it means several times more cables and a board several times larger, and an electrician who does not know the house is to have automation will build an installation that cannot be reprogrammed later, because physically there is no way to do it. That is why the automation design should be drawn up together with the electrical design. If it turns up after the plastering, the scope shrinks and the cost grows: chasing, new plaster, repainting – and by then some things cannot be done at all.
Several of these decisions are made earlier than most people assume.
The first is space. A residence has several distribution boards – for each floor, for the garage, for the pool plant, for the garden – and each of them needs more room than today’s design suggests, because automation modules take up far more space on the rail than the protective devices alone. On top of that comes a cabinet for the electronics: the network, the automation server, the back-up power supply. It needs a room that is dry, cool and accessible for servicing, and preferably not on the other side of a bedroom wall, because the fans hum. That room has to be drawn into the design; if somebody goes looking for it after the fact, it ends up in the garage next to the lawnmower.
Next come the routes outdoors. The gate, the intercom, the garden lighting, the irrigation, the cameras, the technical outbuilding and the charger in the garage all need a cable that passes through the foundation and the ground before the facade and the paving exist. On every such route we lay more ducts than the design calls for, separately for power and for signal cables, and the spare ones stay empty, with a draw wire inside. An empty duct is a small thing in an installation like this, while digging through a finished terrace means taking the terrace up and laying it again.
Shading is the third item, and on a residence one of the most troublesome. With large glazing, external venetian blinds and roller shutters are an installation in their own right: every opening needs power and control, above every one there has to be room for the housing, and somewhere high up there has to be a wind sensor, set to the thresholds the shading manufacturer specifies, that raises the blinds before the wind breaks them. A lowered blind works like a sail, and on open ground I treat that sensor as compulsory; blind manufacturers usually make it their condition too. With this many windows, crank-operated shading stops making sense, and the housing, the cable entry and the power supply for every opening have to be on the facade and electrical drawings, because the shading supplier comes later and finds whatever is there.
Then there are the small things people forget most often and remember when the plaster is fresh: ceiling tracks for motorised curtains, speaker cables for the cinema and the audio zones, a wired network wherever a television or a desk will stand, and deep back boxes throughout the house, because a shallow one has no room for a module, the connectors and a spare length of cable, and the difference in price is nil. And there is power: if a charger is one day to stand in the garage and a heat pump by the pool, the question of connection capacity comes up long before the question of the system.
The last item is surge protection. A residence with automation is full of electronics, from the modules in the board to the motor in every window, and a single surge from the grid can take all of it out at once. The protection is staged – in the board, at the equipment and, in an extensive installation, along the way as well – and it covers the network lines and the camera cables too, especially the ones that leave the building, although almost nobody remembers them. Without proper earthing no arrester has anywhere to send the energy, and an arrester picked at random, without checking the earthing or planning the protection as a whole, mainly makes you feel that something has been done. Part of this follows from regulations, the rest from common sense.
Everything I have described above has one thing in common: it has to be settled before the plastering. It is better to have all the protective devices fitted straight away. If a cable turns out to be missing, you want to find out before the plaster and the floor screeds go on. That is why we photograph the walls with the cable routes in the week they are visible for the last time.
What the system depends on
When a system is being chosen, the question that usually comes up is whether to go with KNX or with a single manufacturer’s system, because most integrators start with the one they sell. That is normal, and not a criticism in itself. I start somewhere else: on whom, and on what, will this house depend for the next 20 years?
The first dependency is a person. Automation does not end on handover day, because the first months after moving in are a time of fine-tuning: a scene that turns on too much light in the morning, a blind that comes down too early. The installer comes back 2–3 months after the move to ask how the house is to live in and to make whatever changes are needed. If you want to modify something later, you will most likely have to call the same specialist, or somebody who works with the same manufacturer’s system. The list of functions is a conversation, because no two builds are the same. And needs change – after three months, after half a year, after a year of living there – so you should be able to change the small things yourself, which for many people is easier than calling a service engineer; the system should let you make such a change easily, without rework and without large costs. If every change needs a visit from one particular person, that is not a fault in itself, but it is a dependency you would rather know about before signing the contract than three years later.
The second dependency is the manufacturer. You build a house for decades, and the modules, controllers and apps will change several times in that period. If the system is the property of one manufacturer – built on its devices, its software and its licences – the house inherits that company’s fate: takeovers, changes of business model, the end of support. An open standard such as KNX is built differently: it belongs to no manufacturer, many makers produce the devices and they can be mixed in one installation, and another integrator working in the same standard can take the project over, provided you have the project file, the passwords and the keys. That does not make single-manufacturer systems worse; some of them are quicker to program, suit the pool or sauna plant better and can be more convenient for the owner in everyday use. I only want it to be known, before the contract is signed, who will be servicing this in five years and on what terms.
The third dependency is the central unit. In some systems every device carries its own logic, so the button talks to the module directly and the light works even when the server, the router and the app are all down. In others everything passes through one central unit, and when it fails, the house fails, because no light comes on from any button until somebody arrives. Both arrangements have their uses, and the requirement I set does not depend on which one it is: the button on the wall has to switch the light locally, without the central unit, without the internet and without the manufacturer’s server, so that the module in the board and its power supply are part of the basic infrastructure of the house. The shading has a defined state in case of failure, and whether it should close or open is not obvious at all – it is settled separately for every room. With gates, what happens without power is decided by the drive and its safety devices – stopping, manual release, access for the emergency services – and the automation gets a say only after them. I wrote about the manufacturer’s server in the texts on the alarm and on the cameras, so here only the short version: a service works for as long as it pays somebody to keep it running.
Finally there is the power. The cabinet with the electronics gets a back-up supply, and when the power comes back the system has to start up by itself, with no logging in and no phone call to the service company. It is also the simplest acceptance test you can imagine: switch off the main switch, wait a moment, switch it back on and see what comes back by itself and what needs a person. I do not know which of today’s companies will still exist in 15 years, which is why I require the basic functions of the house to keep working even if one of them disappears.
Whose project it is
There is one more thing nobody talks about when the contract is signed, and it usually comes out years later: the whole logic of the house sits in the project file. It holds the function of every button, the device addresses, the scenes and, in newer installations, the encryption keys as well. Whoever has that file and its password can change the house; whoever does not can, at most, guess.
In many installations that project exists only on the installer’s laptop – no copy with the owner, no device list, no description of what each module does. As long as the installer answers the phone, nobody notices. When he stops, because he has changed trades, moved away or his company no longer exists, a new integrator stands in front of the house as if in front of somebody else’s computer without the password. A lost project password usually cannot be recovered, and what is left is rebuilding the project from scratch.
On my builds I program this system myself, but you certainly have a part in it, because we have to think through how you will use the house and how you will live in it, so that the functions make sense to you. What matters just as much is that you can edit them yourself afterwards.
At handover I give you the project file with its password and keys, the device list with a description of the functions, the administrator passwords and a plain-language guide for the household, in writing and on video: which button does what, what works after a power cut and whom to call. That is your property, the same as the walls. From the moment of handover only you have access to the system, until you give it to somebody yourself; mine stays only if you ask for it, or for as long as work is still going on. I describe who has access to what in the house more fully in the text on security in layers. It also happens that the system of the whole house is registered to the installer’s account or to the first owner’s, and when the house is sold it turns out that the previous owner still has access – which is why I ask whose account all of this is registered to.
Around the automation, more trades meet than you can see from the outside – the electrics, the shading, the pool plant and the alarm – and they meet at several points. I schedule the work of each trade so that it is finished before the walls are plastered.
What stays separate
There are a few things I do not hand over to the automation, even though it could control them.
I run the alarm separately and connect it to the automation at one agreed point: information flows one way only, from the alarm to the automation, and only as much as the automation needs – for instance that the house is armed, so that it can switch the lights off – while arming and disarming stay with the alarm alone, on a separate installation of its own. I explained why it is done this way in the text on the alarm system, and I will not repeat it here.
Devices keep their own controllers wherever the manufacturer has built safety interlocks into them: the heat pump, the heat recovery ventilation unit, the pool plant and the pool hall dehumidification, the sauna, the gate drive, the car charger. Each of them looks after itself – defrosting, the temperature limit, the photocell in the gate – and that is how it has to stay. The automation gets readings from them and may ask for a setting within the permitted range, but it does not drive the compressor or the heating element directly. One system that rules everything sounds good in a presentation; in practice it means that a single update can break the heating, the gate and the pool at once, and the heat pump engineer who arrives and finds no manufacturer’s controller has nothing to work on.
What also stays separate is everything that does not need to be automatic at all. Automation is there to solve the problems on the list, and if the list is short, the system should be small too.
When it is not worth it – and what to leave for later
When the list of functions is short. If what is left on it is the shading, the gate and the light on the drive, a full bus system for the whole house is overkill, because a few simple modules do the same at a fraction of the complexity and with one person fewer on the service list. The condition is that the installation is laid with extension in mind: cables straight to the board, deep back boxes, spare room. That leaves room to change your mind at little cost.
When the decision comes after the plastering. Then what is left is wireless: modules in deep back boxes, battery-powered sensors, control of groups instead of single points. In an ordinary house that is often enough; in a residence that option is limited, because most of the value lies in things wireless cannot do – power to the shading, the outdoor cable routes, the boards and the cabinet.
When the system is meant to replace the design. No automation will fix a house in which the buttons are in the wrong places because nobody knew where the bed would stand. The function of a button can be reprogrammed; the wall the back box sits in cannot.
I do not promise that the electronics will last 20 years without servicing, because they will not, nor that I will tell you how the automation is arranged in particular houses I have built – I do not do that, in texts or in conversations. Nor do I promise that the app your house runs on will stay the same for the next 20 years, because it certainly will not; that is why the question of who will be able to change things takes up so much room here.
What I ask before I say yes
- What is the house supposed to do by itself – is there a list of functions for every room, written down before any conversation about any system?
- Is the automation design being drawn up together with the electrical design, and does the electrician know that the cables run straight to the board?
- How much room is left in the boards once everything in today’s design has been fitted, and where will the equipment cabinet stand?
- Which outdoor routes have a spare empty duct, and were the cable routes photographed before the plastering?
- Does the button on the wall switch the light on when the central unit is down? And when the internet is down and the manufacturer’s server has been switched off for good?
- What position does the shading move to if the system fails, and who decided that for each room? And the gate: what does the drive do without power, and how is it opened by hand?
- Will the project file, the passwords and the keys go to the owner at handover, who else will have access to them, and what will the owner be able to change without help?
- Where is the point of contact with the alarm, and can the automation only read the alarm, or control it as well?
- Which devices keep their own controller, and what exactly can the automation tell them to do?
Frequently asked questions
KNX or a manufacturer’s system – which to choose for a residence?
That question is shorthand for another one. I ask what the system will depend on: one installer, the existence of one company, its server, one central unit. An open standard answers some of those questions by design, because it belongs to no manufacturer and another integrator can take over the installation – but only if you have received the project file, the passwords and the keys. A single-manufacturer system is sometimes the better choice, as long as the answers to the same questions are satisfactory and written into the contract: local operation without a server, the project and the passwords with you, servicing available from more than one company. Only after those answers does a conversation about a particular system make sense.
Can a smart home be added to a finished house, after the plastering?
Part of it, yes, wirelessly: modules in deep back boxes, battery-powered sensors, control of shading that already had power. What needs cables laid in advance – separate circuits, power to the motors, sensors in the walls, room in the board – cannot be added without chasing the walls. In an ordinary house wireless is often enough; in a residence it usually is not, because what matters most there is the shading, the outdoor cable routes and the equipment cabinet.
Should home automation control the alarm?
No. The automation may know that the house is armed and, for instance, switch the lights off, but arming and disarming belong to the alarm, on its own separate installation, and the contact between the two is one defined point. The reason is simple: an alarm has to be predictable, while automation is, by design, something somebody retunes regularly – so servicing one should not open the other.
How much does automation cost in a residence?
You cannot work it out from the floor area at all. The price depends on the list of functions, the number of shading units and controlled points, the number of systems that have to talk to each other, and when the decision is made, because the same thing costs one amount when it is planned with the electrics and another when it is added after the plastering. Until the list exists, every figure is plucked out of thin air.
I answer other questions – about working together, discretion and how the first conversation goes – in the Questions section.
If you are thinking about a house that is supposed to do part of the work by itself, that conversation should take place before the electrical design. Let’s talk about your project.