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Feature by Julian Edgar Tips & Tricks for wiring new homes If you are building a house, or might do so one day, we have some helpful ideas that will help you get the most out of it. If you think of these things after it has been constructed, it’s usually too late! I am about 80% through building our new home. As an owner-builder, there’s been a lot to learn – and a few surprises along the way. One of the surprises is the amount of wiring. Not just mains wiring, but data cabling, for security cameras, HDMI cables, speaker cables... so many wires! So, if you’re building – or thinking of building – a new home, you need to know what wiring aspects to keep in mind. We’ll start with mains wiring. Mains wiring First, note that in Australia, you will need an accredited electrician to do the wiring. Of course, you can discuss your requirements or plans with them first. In more free countries like New Zealand, you can do some of the work yourself. If you do, it’s a good idea to get an electrician to check over your work and to provide advice. In many respects, mains wiring has changed little over a long time – but the way we use mains power has changed. One example is power points. Once, power points tended to be used for just high current devices – floor heaters, vacuum cleaners, the kitchen kettle and the like. Sure, there were lower-current uses like radios, TVs and hifi systems, but there wasn’t the plethora of low current plugpack-powered devices and USB chargers that now exist. So the number of power points fitted to old homes – perhaps a couple per main room – is now quite inadequate. 66 Silicon Chip In our new home, we have 63 double power points, and through contact with other owner-builders, I’ve found this is often regarded as a low number! Power points located outside are often overlooked – we have ten, including one for the legally required (NSW) rainwater tank pump, and another for a pool pump. Each bedroom typically has four – one on each side of the bed (for a light, clock or phone charger), another easily accessible (for a standing lamp or vacuum cleaner) and one inside each built-in wardrobe (for plugpack-­ powered low-voltage LED lights). One bedroom, where the double bed can be orientated in two different ways, has four bedside power points, so there will be one on each side of the bed irrespective of the two different bed orientations. Sourcing parts If your electrician is happy for you to source the mains cable and parts, do so! There are several Australian suppliers selling cable, power points, lights, switches and so on at excellent prices – often half the retail price. This isn’t for no-name brands, but for quality brands like Clipsal. You can save many thousands of dollars by taking this approach – but ensure you work closely with the electrician so that he or she gets exactly the parts they want. Australia's electronics magazine My home office has eight power points, with six located behind the L-shaped desk. It is cheaper to mount two double power points side-by-side than to use a quad (four-outlet) power point. Quad power points are expensive, and their mounting plates/boxes are also expensive. Of course, you can use power distribution boards rather than multiple power points positioned next to each other – the choice usually depends on whether they will be hidden or able to be seen, and on the total power draw of the devices (limited to a total of 10A or 2300W per outlet). Other power points installed include eight spaced apart in the loft. This large area may be used for all sorts of purposes in the future, possibly including a model train layout; many power points will make any use easy. There’s also a high-mounted power point for the wall-hung TV and high-mounted 15A power points in the bathrooms for infrared heaters. Remotely switched power points Importantly, there are also multiple power points that are switched on and off by normal wall switches. For example, wall switches are used to control two power points located inside the kitchen pantry. These each have plugpacks to power local low voltage LED lighting – one for a lighting strip under the wall-mounted siliconchip.com.au If the electrician is happy for you to source the parts that he or she will use, do so, as you’ll save plenty. Here I am picking up conduit for the underground supply cable. The ute’s tray is also full of cable, power points, switches and many other electrical parts. Seven outside floodlights will be controlled from this six-way switch. Cable is cheap, and when the house is still being built, easy to run. kitchen cupboards, and another that illuminates display shelves in high glass-fronted kitchen cupboards. Another remotely switched power point in the kitchen is for a booster fan for the range hood. Another two remote switched power points are located in the loft, allowing wall switches in the lounge to turn the sound system amplifiers on and off. Wall plate switches for remotely switched power points should include a pilot light to show the remote device is powered. The exception is where it is obvious that the remote power point is on; for example, it controls lighting. Neon pilot lights are available that slot straight into normal wall plates; for example, replacing one of the switches on a two-gang plate. On the advice of our electrician, the kitchen fridge is on a separate circuit. There are two reasons for this: 1. He suggested that the most common Earth leakage problem is caused by the fridge, and so isolating the problem is easy if that’s all that is on that circuit. 2. When people go away on holiday, they often switch off everything but the fridge – this is easily achieved if the fridge is on a separate breaker. Another two power feeds that are on separate circuits are for the pool water pump and the waste treatment system (the modern name for what was once a septic tank). The reason for running these on separate circuits is that, by fitting appropriate controllers at the siliconchip.com.au switchboard, it will be easy to operate these on excess solar power or offpeak tariffs. EV charging A major cable that we installed was for an outside charging point for an electric vehicle (EV). Single-phase AC chargers for EVs are typically rated at up to 7kW (about 30A at 230V). This high current requires its own circuit and, depending on the length of cable required, may need cable with quite a large cross-section of copper. The calculator at siliconchip.au/link/ ac69 is a useful tool to double-­check the cable being used by the electrician. In our case, because of the length, he used 10mm2 cable. Mains cable usually comprises Active, Neutral and Earth wires in a flat white cable. This is called TPS (thermoplastic-­sheathed) cable. A shut-off switch is needed at the EV charger – killing two birds with one stone, he used a 32A three-pin weatherproof external power outlet that has an inbuilt switch. The charger plugs into this power outlet. Many EVs now also have V2L (vehicle to load) functionality, where the car can act as a mains source. I own an MG4 EV that can provide up to 3kW – expect EVs in the future to be able to deliver more. So, rather than firing up a generator when we have a (not infrequent) blackout, another cable was laid to the EV charging point to allow the house to be powered by the EV. To protect anyone working on the external mains power lines when this occurs, the connection with mains must be broken by a switch – ie, the house is switched to back-up power The electrician will ask for your desired location and spacing of the various wall switches and fittings, so work this out ahead of time. From left to right, these mounting plates are for a light switch, isolation switch for a remote-controlled ceiling fan, space for the fan remote and the room temperature sensor mounting plate. Australia's electronics magazine March 2026  67 Where to locate the electronics Early in our house planning, I was thinking of making my home office the electronic ‘centre of things’. I envisaged a wall-mounted cabinet with terminations for Cat 6 cabling, cabling from the outside shed (for the security cameras) and speaker cabling for a whole-of-house audio system. Then I realised the cabinet would need to be huge because it would also contain the audio amplifiers, the digital video recorder (DVR) for the security system, the network switch/router and so on. So instead, I nominated some shelves in the loft space for all these functions. In a house without a loft, or where you want ground level access, you could use the equivalent of a linen cupboard. When designing a house, incorporating such an extra space is straightforward. Deciding on the location for the information centre is very important because it determines the route of many of the cable runs – especially the Cat 6 cables. If you choose to remote mount audio amplifier(s), it will also determine the location of speaker cables, line level (RCA) signal cables and possibly HDMI cables. and in doing so, disconnected from the mains. Note that this is not V2H (vehicle to house), where the EV’s battery seamlessly becomes part of the house system, charging and discharging in a two-way process. Unfortunately, because of power company regulations and the lack of suitable cars in Australia, V2H is still on the horizon. Heavy loads and dimmers Another pair of cables that surprised me because of their size were those for the stove and cooktop. Our electrician used 6mm2 for the cooktop and 4mm2 for the oven – this took into account any size or type for these two appliances, now or in the future. Another mains power aspect to keep in mind is lighting dimmers. The benefit of dimmers is that the current consumption falls proportionally as you dim the lights, so you can have plenty of lighting brightness available when required, but typically use little power at normal brightness levels. Modern smart dimmers have memory and slow-dimming functions, and the dimmer knob can be used as a normal on/off switch just by pressing it. These dimmers can also be easily wired to operate in two, three and even four way switching circuits, giving a lot of versatility in how you control lights. Nearly every internal light in our new house is operated by a dimmer, and the hallway lighting is controlled by three-way switching – one switch at each end and one in the middle. If using dimmers, ensure that you select LED lights that are dimmable. Some aren’t. The switchboard Consider where you want the switchboard to be located. It doesn’t need to be in the meter box; a location nearer to the area of maximum current draw (eg, the kitchen) will reduce the required lengths of expensive heavyduty cable. Standard 1.5mm2 cabling – typically for lighting – and 2.5mm2 for power points are both quite cheap because they are used in vast quantities. Thicker TPS cable is disproportionately much more expensive – it’s cheaper to make the main power feed, that doesn’t use TPS cable, longer. I chose to mount the switchboard centrally in the house loft. The advantages include proximity to the hot water system, kitchen & laundry, and plenty of space to mount the switchboard and later expansions (solar diversion relays etc). The disadvantage is that access to the switchboard is via dropdown loft steps. Modern smart lighting dimmers are energy efficient, remember their last setting and can be programmed for maximum and minimum light output. They are also easy to wire for two, three or even four way switching. 68 Silicon Chip Australia's electronics magazine Run any cables that might be needed in the future while the house is being built. This outside box contains a power feed for an air conditioner, should one be needed. When considering mains wiring, don’t forget outside lighting. Two-way switching of lighting in an outside shed is useful (you can operate the shed lights from both the house and shed), and house-mounted floodlights can provide excellent yard illumination, especially in dark rural areas. Many people also use decorative lighting along the side of driveways. Finally, on mains wiring, it costs little to run extra cables at the time the house is being built – regular thickness TPS cable is cheap, and access for the electrician through a half-built house is quick and easy. Therefore, if you can foresee any potential future requirement for power in a location, get the electrician to run that cable at construction time. For example, we do not plan on having air-conditioning since our energy modelling suggests we shouldn’t need it. But what if that modelling is wrong? In case it is, 15A cables have been run to each end of the house, terminating in outside weatherproof boxes. If air conditioners do need to be later installed, accessing power will take only moments, with isolation switches replacing the blank front faces of the boxes. Audio-visual cabling Cabling for audio-visual purposes can be bigger than Ben Hur – but let’s start with speaker wiring. While the current fashion is for Bluetooth speakers (eg, the rear speakers in a home theatre system), I much prefer hard wiring. If it’s done when the house is being built, it is quick, simple and easy – and of course, you can do it yourself. siliconchip.com.au Note that depending on the type of home theatre system you are running, you may need to wire in a lot of speakers! Speaker cable can be expensive, but there is a solution. If instead of speaker cable you select low-voltage garden lighting cable, you’ll find a 100m roll costs about $200 – and that’s for cable with a 3.4mm2 cross-section! This is about the equivalent of AWG 12, but it is much cheaper than similar-size cable sold as speaker wire. This cable is sufficiently thick for any length of speaker runs in a normal house – for short runs, you can of course use thinner cable. It will work just as well as speaker cable. Audio guru Douglas Self agrees that the type of cable used for speakers doesn’t really matter. In his book “The Design of Active Crossovers” (Elsevier, 2011), he writes, “The main factors in speaker cable selection are therefore series resistance and inductance. If these parameters are less than 100mW for the roundtrip resistance and less than 3μH for the total inductance, any effects will be imperceptible.” So speaker cable doesn't need to be anything special, as long as its resistance is low enough. You will need to decide how to terminate each end of the speaker cables. Normally, termination at the speaker end is via a wall plate with binding posts or jacks. However, this adds considerable expense and requires further cables to connect the wall plates to the speakers. An alternative is to use a brushed plate. With this approach, the cable simply passes through the wall plate brushes to the speaker or amplifier. When cabling for speakers, don’t forget any outside areas like a patio or deck. Depending on where the various amplifiers and signal sources are, you may also need to use HDMI and/or RCA (line level) connections between them. For example, in my house, the subwoofer amplifier is remote-mounted in the loft and is connected via long line level cables to the sub-out connection of the home theatre amplifier (near the TV) and a short line level cable to a Bluetooth audio input. It connects to both sources via a custom mixing cable, as described in an article from March 2025 (siliconchip.au/ Article/17787). siliconchip.com.au Low-voltage garden lighting cable is one of the cheapest ways of getting heavy-duty cable suitable for long runs. It’s usually much cheaper than similar size speaker cable. Cable for a speaker in an outside deck area. I chose not to use a wall plate with sockets but to simply feed the cable through a sealed hole in the wall cladding to the speaker. We didn’t have a home theatre system in our previous house. Because I was a little uncertain how all the cabling would play out, we set up the entire system in the unfinished house so that all cable runs could be checked before plasterboard closed off access. RJ45 plugs to Cat 6 cable and finding it very difficult (especially with thicker 23AWG cable), I decided to buy pre-terminated cables. Because these cables are available in a wide variety, it was easy to select cables of the right length. Wall plates are also available with female/female Cat 6 connectors, so running the Cat 6 cabling is as easy as just plugging the cables into the back of the wall plates. Cat 6 cabling Cat 6 is the most universal cable you can run in your house. It can be used to network computers, printers, security cameras, security systems, games consoles, smart TVs and VoIP phones. It can even network one switch to another switch and connect a wireless access point to the network. Additionally, it can be used as low-voltage power cabling, eg, for operating remote relays or intercoms, or for sensing environmental factors like temperature or wind speed or for powering a wireless internet dongle. Via adaptors, HDMI and USB signals can be sent down long runs of Cat 6. In short, think of Cat 6 cabling as the communications backbone of the house. In our house, I have run Cat 6 cabling from the information centre in the loft to: • my home office • my wife’s work desk • the two main bedrooms • the kitchen • the TV in the lounge • the shed • each external security camera location After fiddling with fitting my own Australia's electronics magazine Security cameras Security camera systems are available in three types: wireless (no cabling), analog (using coaxial cable for the signal and a pair of wires for power) and digital IP cameras (using Cat 6 cabling and POE [power over Ethernet]). In our house, built on a five-­hectare rural block, we use wireless for long-distance monitoring, and IP cameras for the house and shed. A major advantage of IP cameras in our application is that the shed is connected to the house via Cat 6 cable, and by Optic-fibre based cables can be used for long HDMI runs. For example, these can be used to connect a security camera digital video recorder (DVR) to the main TV, allowing review of footage on a large monitor. March 2026  69 using a network switch in the shed, multiple security camera feeds can be fed via this single cable to the DVR in the house. Depending on the location of the DVR, you may need to use a long HDMI cable to connect it to a viewing monitor. Many people use their main TV as the security monitor (it’s likely to be the largest display in the house), so either the DVR needs to be located near the TV (and thus all the camera cables also need to come to this spot), or a long HDMI cable needs to connect the DVR to the TV. We chose the latter approach. Conventional HDMI cables are limited to about 15m. However, longer active fibre-optic HDMI cables are available in lengths up to 30m. Note that these must be connected the right way around; they have a transmitter (labelled ‘source’) and receiver (labelled ‘display’) built into the respective plugs – something I initially didn’t realise! Fibre-optic HDMI cables are also subject to less RF interference than conventional HDMI cables (and produce less interference) but they have a downside. Should the electronics in the transmitter and receiver (integrated into the plugs) fail, they will be difficult to replace. A more reliable alternative is to use RG-6 coaxial cable with SDI (Serial Digital Interface) converters at each end. However, there is a further subtlety with a remote-mounted DVR. To operate the DVR (eg, to play back security footage) requires a mouse connection to the DVR, and that mouse needs to be operable from where you can see the TV. Conventional USB cables are limited to about 5m (for a longer cable you need an amplified ‘repeater’ cable), but a Bluetooth mouse will usually work over the required distance. Selecting a Bluetooth one-handed finger trackball mouse means you don’t have to rest the mouse on a surface when using it, and the mouse can easily be stored near the TV when not being used. Other stuff If you are building a house – or having one built for you – don’t forget you can do whatever idiosyncratic things you want with the non-mains wiring. For example, in our solar passive house, I want to be able to display and log temperatures throughout the house, including temperatures in every room, in the concrete slab (that stores heat and can act as a heatsink) and near the ceiling in two rooms with raked ceilings. This sensing is achieved using thermistors, including some buried in plastic tubes inside the concrete when the slab was poured. Signals are fed to two Picolog 1012 analog loggers with data displayed on a touchscreen PC located in the hall, with an HDMI-fed repeater screen in my office. Several hundred metres of cables are used. Home automation I decided against using full home automation because its advantages (automatic control of door locks, light dimming, air conditioners, opening and closing of vents etc) seemed to me to be outweighed by its complexity and the likely life of such specific hardware. A finger trackball mouse is a convenient way of operating a remote security camera DVR when the main TV is being used as the monitor. It overcomes the need for a long, active USB cable. Of course, you might decide otherwise, in which case you’d definitely want to run as much of the wiring as possible during construction of the home. Many home automation devices will work over Cat 6, so make use of that where possible. Conclusion The wiring decisions that you make have the potential to greatly alter the liveability, energy efficiency and cost of a new home. Think through the different systems very carefully, as it is easy and cheap to install wiring when the house is being built, but expensive and difficult to do so afterwards. Where possible, test the wiring as it is being installed. If it can be done, temporarily set up whole systems (eg, security cameras) to ensure you’ve not forgotten any required cables. Finally, by working closely with an electrician for the mains wiring, and doing the other cabling yourself, it’s also possiSC ble to save a lot of money. What about wireless? A brush plate on an internal brick feature wall. Brush plates allow cables to pass straight through, so pre-terminated cables (eg, HDMI) can be easily used. 70 Silicon Chip Australia's electronics magazine A good rule of thumb to use is: when connecting to a portable device, use wireless. When connecting to a device that stays in one location, use Cat 6. Cables are more reliable and have higher bandwidths than wireless. They are also far less subject to interference. For example, we have experienced WiFi dropouts near the kitchen when a microwave is running! siliconchip.com.au