Smart home technology has moved well beyond the novelty stage. Automated lighting, multi-room audio, whole-house heating control, integrated security, EV charging, solar monitoring: these are now mainstream features in ambitious residential projects. The homeowners who get the most from them are the ones who designed the infrastructure in at the start. The ones who try to retrofit it later spend significantly more and still end up with compromises.
If you're building an extension, doing a loft conversion, or embarking on a major renovation, the building works give you a window to install infrastructure that would otherwise require significant disruption. Use it. Even if you don't install the smart home systems immediately, putting the right conduits, cables, and network infrastructure in place now costs a fraction of doing it retrospectively.
Network Infrastructure is Everything
The single most important smart home infrastructure decision is the network. Most smart home problems, including unreliable automation, slow responses, and devices that drop offline, trace back to poor Wi-Fi coverage or network congestion. The solution is wired: a structured cabling installation that puts a network socket (RJ45) in every room, feeding back to a central patch panel and a managed switch.
The standard to install is Cat6 or Cat6a. Cat5e is still technically adequate but Cat6 is only marginally more expensive and provides headroom for future 2.5Gbps or 10Gbps connections. Install cables in star topology: individual runs from each room to a central distribution point (typically a comms cabinet in a utility room, loft, or cupboard).
How many cables per room? More than you think. A bedroom might need: TV point, desk or bedside network point, home hub future point. A living room: TV, media cabinet, possibly two additional positions for flexibility. Kitchen: at least two. Home office: three minimum, probably four. Running three cables to a room while the walls are open costs almost nothing extra. Running one and wishing you'd run three costs a lot.
The cost of structured cabling during a build is roughly £80-£150 per point installed, including cable, socket, patch panel entry, and labour. Retrofitting through finished walls and ceilings costs two to three times more and involves decoration reinstatement.
Wi-Fi Coverage Planning
Even with wired connections in every room, you still need Wi-Fi: for phones, tablets, smart speakers, IoT devices, and anything that doesn't have a network port. The right solution for a larger house is a mesh system with wired backhaul: access points in each area of the house, connected back to the router via Cat6 cables (the wired network you've already installed), providing seamless roaming coverage throughout.
Consumer mesh systems (Eero, UniFi, TP-Link Omada, Ubiquiti) have become excellent. The enterprise-grade systems (UniFi is the most popular semi-professional choice) offer significantly more control, stability, and diagnostic information at a modest cost premium. For a larger house with smart home systems, enterprise-grade is worth the investment.
During first fix, plan and install wired network drops at the proposed locations for your access points. Ceiling-mounted access points (connected via a PoE switch, which powers them over the network cable) provide the best coverage and are the most common choice for installations planned from the start.
Control System Choices
The smart home control layer is the software and hardware that ties your devices together. The main choice is between:
Platform-based systems (Apple HomeKit, Google Home, Amazon Alexa, Samsung SmartThings). Consumer-accessible, large device ecosystems, straightforward to set up, relatively affordable. Limitations: dependent on external cloud services, less reliable for complex automation, privacy considerations, and vulnerability to product discontinuation.
Professional control systems (Control4, Crestron, Lutron). Installed and programmed by specialists, extremely capable and reliable, excellent user experience when well-designed. Significantly more expensive: a professionally installed Control4 system for a medium-sized house can cost £15,000-£50,000 or more. Requires ongoing support from a dealer.
Open-source/prosumer systems (Home Assistant, KNX, Loxone). KNX and Loxone are bus-based systems where devices communicate over dedicated wiring rather than Wi-Fi, offering exceptional reliability and independence from cloud services. Home Assistant is software that runs on a local server and integrates with almost every smart home device on the market. These options require more technical knowledge but offer outstanding long-term control and privacy.
For most homeowners, a combination of Home Assistant (for local control and automation) with Matter-compatible devices (the new interoperability standard that works across ecosystems) is currently the most forward-looking and flexible approach at consumer price points.
Install conduit where cabling is uncertain. Run empty conduit (32mm or 50mm corrugated conduit) through walls and ceilings in areas where you might want to add technology later. A draw wire in the conduit means adding cables later is simple. This is particularly relevant for AV equipment, projectors, and control system wiring.
Electrical Planning for Smart Home
Smart home systems add to electrical planning complexity. Things to discuss with your electrician during first fix:
Dimmer-compatible circuits. Smart dimmers require neutral wires at the switch position, which are not present in traditional UK wiring (which uses switch lines only). If you want to retrofit smart switches later, or install them now, ensure neutral wires are run to every switch position.
Dedicated circuits for smart systems. EV chargers, solar inverters, ASHP control units, and home server/networking equipment all benefit from dedicated circuits. Plan these into the consumer unit design rather than adding spurs later.
Smart consumer unit. Modern consumer units with monitoring capability (such as those compatible with Home Assistant or Sense energy monitors) let you track per-circuit energy consumption. This is useful for identifying waste, managing EV charging schedules, and optimising solar self-consumption.
Audio and Video Distribution
Multi-room audio can be delivered over Wi-Fi (Sonos, Denon HEOS, Apple AirPlay devices) or over wired speaker connections. Wi-Fi solutions are simpler to install but dependent on network quality. Wired speaker connections are more reliable but require cabling during first fix.
For whole-house audio planned from the start, run speaker cables (minimum 2.5mm2 twin) to each room from a central amplifier location during first fix. Even if you don't connect a system immediately, the infrastructure is there. Retrofit speaker cabling through finished walls is a serious job.
For video distribution (sending HDMI signals from a central rack to multiple rooms), HDMI over IP or HDBaseT extenders over Cat6 have replaced dedicated video coax cables. If you've run Cat6 throughout, you have the infrastructure for video distribution too.