智能家居材料预埋指南 (Smart Home Pre-installation Guide)
1. Why Pre-installation Matters
Smart home retrofitting after renovation is expensive, messy, and often aesthetically compromised. Proper pre-installation during renovation ensures clean wire management, reliable connections, and future-proofing. This guide covers conduit planning, wiring, sensor positioning, and infrastructure requirements.
Renovation Phase Checklist
| Phase | Smart Home Tasks |
|---|---|
| Design | Select ecosystem, map device locations, plan network topology |
| Demolition | Mark new outlet locations, identify hub placement |
| Electrical rough-in | Run neutral wires to all switch locations, install extra conduits |
| Low-voltage rough-in | Network cables, sensor wires, speaker wires, security |
| Wall closing | Photograph all wire runs, label both ends, test continuity |
| Finishing | Install smart switches, sensors, hubs, APs |
| Commissioning | Network setup, device pairing, automation programming |
2. Smart Home Ecosystem Selection
Platform Comparison
| Ecosystem | Protocol | Local Control | Hub Required | Voice Assistant | Notes |
|---|---|---|---|---|---|
| Apple HomeKit | Thread, Wi-Fi, Bluetooth | Yes (with Thread Border Router) | Apple TV / HomePod / HomePod mini | Siri | Premium, privacy-focused, best iOS integration |
| Xiaomi / Mi Home (米家) | Zigbee 3.0, BLE Mesh, Wi-Fi | Partial (depends on device) | Xiaomi Gateway / Multimode | Xiao Ai | Widest device selection in China, cost-effective |
| Aqara | Zigbee 3.0, Thread, Wi-Fi | Yes (with Aqara Hub M2/M3) | Aqara Hub M2/M3 | Siri, Alexa, Google | Good HomeKit support, quality hardware |
| Tuya / Smart Life | Wi-Fi, Zigbee | Partial | Tuya Gateway | Alexa, Google | Massive device compatibility, budget |
| Home Assistant | Zigbee, Z-Wave, Thread, Wi-Fi, MQTT | Yes (fully local) | HA server (Raspberry Pi / NAS) | Any | Ultimate flexibility, DIY, technical skill needed |
| Huawei HiLink (鸿蒙) | Wi-Fi, BLE, PLC | Yes | Huawei router / hub | Celia | Growing ecosystem, PLC wired reliability |
Protocol Comparison
| Protocol | Range | Bandwidth | Power Use | Mesh | Best For |
|---|---|---|---|---|---|
| Zigbee 3.0 | 10–30m indoor | 250 kbps | Very low | Yes | Sensors, switches, locks |
| Z-Wave | 30–100m indoor | 100 kbps | Very low | Yes | Sensors, locks, thermostats |
| Thread | 10–30m indoor | 250 kbps | Very low | Yes | Next-gen standard, Matter compatible |
| Wi-Fi | 30–50m indoor | 100+ Mbps | High | No | Cameras, displays, speakers |
| Bluetooth LE / BLE Mesh | 10m | 1–2 Mbps | Low | Yes (mesh) | Proximity sensors, remotes |
| Matter (over Thread/Wi-Fi) | Depends on underlying | Varies | Varies | Yes | Universal standard (future-proof) |
| RS-485 (wired) | 1000m+ | High | N/A | No | Commercial, wired reliability |
Recommendation: Plan for Zigbee 3.0 or Thread for sensors and switches, Wi-Fi for cameras and displays, and ensure your hub supports Matter for future compatibility.
3. Conduit Pre-Planning (管道预埋)
General Rules
- Every switch box needs a neutral wire — this is the single most important pre-installation rule
- Run at least one extra empty conduit to each major location for future expansion
- Use 20mm conduits (not 16mm) for switch locations to allow future cable additions
- Separate power and low-voltage conduits by minimum 300mm
Conduit Layout by Room
Living Room
| Location | Conduits Needed | Wire Types | Notes |
|---|---|---|---|
| TV wall | 3 x 20mm conduits | Power + HDMI/ethernet + spare | HDMI conduit with pull string |
| Sofa wall | 2 x 20mm conduits | Power + ethernet | For floor lamp + smart speaker |
| Ceiling center | 2 x 20mm conduits | Power (ceiling light) + neutral | Smart switch needs neutral |
| Corner (curtain) | 1 x 20mm conduit | Power at ceiling height | For motorized curtain track |
| Window (sensor) | 1 x 16mm spare | Optional wired contact sensor | Usually wireless is sufficient |
Kitchen
| Location | Conduits Needed | Wire Types | Notes |
|---|---|---|---|
| Under-sink | 2 x 20mm | Power + spare | Water purifier, leak sensor, garbage disposal |
| Above cooktop | 1 x 20mm | Power | Smart range hood |
| Countertop level | 2 x 20mm | Power | Smart appliance outlets |
| Ceiling | 1 x 20mm | Power | Smart light / gas detector |
| Fridge area | 1 x 20mm | Power (dedicated circuit) | Smart fridge |
Bedroom
| Location | Conduits Needed | Wire Types | Notes |
|---|---|---|---|
| Each side of bed | 2 x 20mm | Power + USB | Bedside outlets + smart lamp |
| Door | 2 x 20mm | Power (switch) + neutral | Smart switch + scene panel |
| Window | 1 x 16mm | Power (optional) | Motorized curtain/blind |
| Ceiling | 2 x 20mm | Power + neutral | Smart light + optional projection screen power |
Bathroom
| Location | Conduits Needed | Wire Types | Notes |
|---|---|---|---|
| Mirror area | 2 x 20mm | Power | Smart mirror, LED lighting |
| Ceiling | 2 x 20mm | Power | Smart exhaust fan, heater, light |
| Toilet area | 1 x 20mm | Power | Smart toilet seat |
| Shower area | 1 x 16mm | Power (IP-rated) | Digital shower controller (optional) |
| Wall (sensor) | 1 x 16mm spare | Optional wired humidity sensor | Usually wireless |
Switch Box Requirements
| Switch Type | Box Size | Wiring Needed |
|---|---|---|
| Standard single gang | 86 x 86mm | Live + Neutral + Load (each way) |
| Multi-gang (2–3 gang) | 86 x 86mm (deep) | Live + Neutral + multiple loads |
| Scene panel / touchscreen | 86 x 86mm (deep 50mm+) | Live + Neutral + ethernet (recommended) |
| Curtain switch | 86 x 86mm | Live + Neutral + 2 switched legs |
| Dimmer switch | 86 x 86mm (deep) | Live + Neutral + Load + earth |
Critical: Request electricians to run neutral wire (零线) to EVERY switch location. Traditional Chinese wiring often omits neutral at switches (switch only breaks live). Smart switches need both live and neutral to power their electronics.
4. Wiring for Smart Switches
Smart Switch Wiring Diagram (Text)
Distribution Box
|
|--- Live (火线) --------------------+--- to smart switch L terminal
| |
|--- Neutral (零线) ------------------+--- to smart switch N terminal
|
+--- Earth (地线) --------------------+--- to smart switch E terminal (if metal)
Smart Switch
|
+--- L1, L2, L3 (load wires) -----> to each light fixtureWire Requirements
| Connection | Wire Size | Type | Notes |
|---|---|---|---|
| Live to switch | 2.5mm² | BV | Standard |
| Neutral to switch | 2.5mm² | BV | Must be added if not present |
| Load wires (to lights) | 1.5–2.5mm² | BV | Per lighting circuit |
| Earth | 2.5mm² | BVR | Required for metal switch plates |
Smart Switch Types
| Type | Neutral Required | Installation | Best For |
|---|---|---|---|
| Zero-fire version (零火版) | Yes | L + N + Load | New construction, renovation (preferred) |
| Single-fire version (单火版) | No | L + Load only | Retrofit (existing homes), but less reliable |
| No-neutral version (无零线) | No | L + Load | Last resort; requires bypass capacitor |
Always choose zero-fire version (零火版) for new installations. Single-fire switches have issues with low-wattage LED flickering and are less reliable.
5. Sensor Mounting Positions
Sensor Placement Guide
| Sensor Type | Recommended Height | Location | Spacing | Notes |
|---|---|---|---|---|
| Motion (PIR) | 2.2–2.5m | Ceiling corner, facing entry | 5–8m coverage radius | Avoid pointing at AC vents, windows |
| Motion (mmWave) | 2.5–3.0m | Ceiling center of room | 6m coverage radius | Detects presence (breathing), not just motion |
| Door/Window Contact | Door frame height | Top corner of door/window | One per door/window | Magnet on door, sensor on frame |
| Temperature/Humidity | 1.5m | Interior wall, shaded | One per zone/room | Away from direct sun, AC vents, kitchens |
| Light (Lux) | 1.5m | Interior wall | One per room | Away from direct lamp light |
| Water Leak | Floor level | Under sinks, near water heater, washing machine | One per wet area | Place on lowest point |
| Smoke Detector | Ceiling center | Each room, hallway | Per fire code | Interconnected if wired |
| Gas Detector | Ceiling (natural gas) or floor (LPG) | Kitchen, near gas appliance | One per gas appliance area | Natural gas rises; LPG sinks |
| Air Quality (VOC/PM2.5) | 1.5m | Living room, bedroom | One per floor | Away from kitchen, open windows |
| Noise | 1.5m | Living room, nursery | One per room | For automation triggers |
mmWave Sensor vs PIR
| Feature | PIR (Passive Infrared) | mmWave (Millimeter Wave Radar) |
|---|---|---|
| Detection | Body heat movement | Micro-movement (breathing, typing) |
| "Still person" detection | No (turns off if sitting still) | Yes (detects presence even when still) |
| Through materials | No (line of sight) | Yes (through thin walls, glass, fabric) |
| False triggers | Moderate (pets, sunlight) | Low |
| Cost | ¥20–80 | ¥80–300 |
| Power | Battery or wired | Wired (5V or 12V) |
| Recommended Use | Hallways, entry, closets | Living rooms, bedrooms, bathrooms |
mmWave Sensor Installation Checklist
- [ ] Mount on ceiling for best coverage (360° models)
- [ ] Wall mount at 2.5m+ if ceiling not possible (directional models)
- [ ] Power: run 5V USB-C or 12V DC wire to sensor location
- [ ] Avoid placing near rotating fans, curtains, or moving objects that trigger false detection
- [ ] Configure detection zone in software to exclude false trigger areas
- [ ] Set appropriate "unoccupied delay" (30–60 seconds recommended)
6. Network Cable Requirements
Cable Category Selection
| Cable Category | Max Speed | Max Distance | Suitable For | Recommendation |
|---|---|---|---|---|
| Cat 5e | 1 Gbps | 100m | Basic internet | Minimum — avoid for new installs |
| Cat 6 | 1–10 Gbps | 55m (10G) / 100m (1G) | Gigabit + future | Recommended for most homes |
| Cat 6a | 10 Gbps | 100m | 10G backbone, PoE++ | Ideal for future-proofing |
| Cat 7 | 10 Gbps | 100m | Shielded installations | Overkill for most; harder to terminate |
| Cat 8 | 40 Gbps | 30m | Data centers | Unnecessary for residential |
Recommendation: Install Cat 6a (六类a) to all fixed locations. The cost difference from Cat 6 is minimal during construction, and it supports 10 Gbps for future network upgrades.
Network Drop Points
| Location | Number of Cat 6a Drops | Notes |
|---|---|---|
| TV wall | 3–4 | TV, set-top box, game console, spare |
| Each bedroom | 2 | Desktop PC, spare |
| Study / office | 4–6 | Desktop, NAS, printer, monitor, spare |
| Kitchen | 1 | Smart display / tablet |
| Living room ceiling | 1 | Wi-Fi AP (ceiling mount) |
| Each floor hallway | 1 | Wi-Fi AP |
| Distribution box | As needed | Smart home hub, network switch |
| Door entrance | 1 | Smart doorbell / camera |
| Balcony | 1 | Security camera |
| Garage | 1 | EV charger communication (optional) |
PoE (Power over Ethernet) Devices
| Device | PoE Standard | Power | Notes |
|---|---|---|---|
| IP Camera | 802.3af (PoE) | 15.4W | Most common |
| Wi-Fi AP (ceiling) | 802.3af (PoE) | 15.4W | Ubiquiti, TP-Link Omada |
| Smart doorbell | 802.3af (PoE) | 15.4W | Wired alternative to battery |
| IP Phone | 802.3af (PoE) | 15.4W | Optional for home |
| PoE Switch | 802.3at (PoE+) | 30W | For downstream devices |
| Smart display | 802.3at (PoE+) | 30W | Wall-mounted control panel |
Network Topology Recommendation
Internet (fiber optic modem / ONT)
|
|--- Main Router (with 2.5G WAN port)
|
+--- 2.5G/10G Switch (in distribution box)
|
+--- Cat 6a to each room drop
+--- Cat 6a to ceiling APs
+--- Cat 6a to PoE cameras
+--- Cat 6a to smart home hub
+--- Cat 6a to NASNetwork Installation Checklist
- [ ] Run minimum Cat 6a, solid copper (not CCA — Copper-Clad Aluminum)
- [ ] Use shielded cable (STP) only if running near power lines; otherwise UTP is fine
- [ ] Label both ends of every cable
- [ ] Test every cable with certification tester (Fluke or equivalent)
- [ ] Leave 1m service loop at both ends
- [ ] Use structured media enclosure / patch panel in distribution box
- [ ] Conduit size: minimum 20mm for network cable runs (allow for future re-pull)
- [ ] Do NOT run network and power in the same conduit
7. Central Hub Placement
Hub Placement Criteria
| Factor | Requirement | Why |
|---|---|---|
| Centrality | Central location in home | Maximizes Zigbee/Thread range to all devices |
| Elevation | 1.5–2.0m height | Avoids floor-level obstruction |
| Power | Always-on outlet (not switched) | Hub must run 24/7 |
| Network | Ethernet connection (not Wi-Fi) | Reliable, low-latency backbone |
| Ventilation | Open area, not enclosed in metal box | Zigbee/Thread signals attenuate in metal enclosures |
| Accessibility | Accessible for maintenance | USB ports, reset buttons, SD cards |
Recommended Hub Locations
| Home Type | Best Hub Location | Notes |
|---|---|---|
| Small apartment (1–2 BR) | Living room shelf or TV cabinet | Central, easy access |
| Large apartment (3+ BR) | Central hallway ceiling or utility room | Maximize radio range |
| Multi-story villa | Each floor has a hub, wired together | Zigbee doesn't cross floors well |
| With NAS | Next to NAS / in equipment rack | Consolidate infrastructure |
| With HomeKit | Near Apple TV / HomePod | Thread Border Router co-location |
Equipment Rack / Distribution Box Setup
| Component | Size / Space | Notes |
|---|---|---|
| Router | 1U or desktop | 2.5G WAN minimum |
| Switch | 8–16 port PoE+ | Managed switch with VLAN support |
| Smart Home Hub | Desktop (15 x 15 x 5cm) | Aqara M3, Home Assistant, etc. |
| NVR (camera recorder) | 4–8 bay | If using wired cameras |
| NAS | 2–4 bay | Media, backups, Home Assistant |
| Patch panel | 12–24 port | Organize all network drops |
| UPS | 600–1500VA | Keep network running during outages |
| Enclosure | 400 x 300 x 120mm minimum | Ventilated metal or plastic cabinet |
Equipment Rack Checklist
- [ ] Dedicated 16A circuit for network equipment
- [ ] UPS backup for router, switch, and hub
- [ ] Ventilation: minimum 2 fans or passive vents
- [ ] Cable management: velcro ties (not zip ties) for serviceability
- [ ] Label every cable at both ends
- [ ] Leave 30% spare ports on switch for future devices
- [ ] Configure VLANs: separate IoT devices from main network
- [ ] Document IP addresses and device assignments
8. Special Considerations
Smart Curtain Pre-installation
| Curtain Type | Power Location | Conduit | Notes |
|---|---|---|---|
| Motorized track | Ceiling, end of curtain rod | 20mm conduit to one end | Measure track length + 15cm for motor |
| Roller blind | Ceiling or wall, top of window | 16mm conduit | Battery options available |
| Venetian blind | Wall, beside window | 16mm conduit | Smart tilt/raise control |
| Roman shade | Ceiling | 16mm conduit | Requires compatible motor |
Smart Lock Pre-installation
| Door Type | Requirement | Notes |
|---|---|---|
| Wooden door | Standard mortise size (6068 or 7255) | Measure before purchasing lock |
| Metal security door | Confirm lock body compatibility | May need adapter plate |
| Double door | Confirm latch direction | Smart locks are handed |
| Glass door | Special glass door lock | Different mechanism |
Tip: No wiring needed for smart locks (battery powered), but consider pre-running a low-voltage wire for future hardwired models.
Smart Mirror / Bathroom TV
| Item | Power Location | Water Protection |
|---|---|---|
| Smart mirror | Above mirror, concealed | IP44 minimum |
| Bathroom TV | Above vanity or in niche | IP65 for shower-adjacent areas |
| Heated towel rack | Wall, beside shower | Dedicated 16A circuit |
Projector Pre-installation
| Item | Requirement | Notes |
|---|---|---|
| Ceiling mount | Reinforced ceiling box or concrete anchor | Verify projector weight capacity |
| HDMI conduit | 25mm conduit from TV rack to projector | HDMI 2.1 requires high-quality cable |
| Power | 1 x 10A outlet at projector location | |
| Screen power | 1 x 10A outlet at screen location | For motorized screen |
| Speaker wire | 2 x 16mm² to rear speaker locations | If planning surround sound |
9. Complete Pre-installation Checklist
Electrical
- [ ] Neutral wire at EVERY switch location
- [ ] 20mm conduits at all switch boxes (not 16mm)
- [ ] Extra empty conduit to major locations
- [ ] Dedicated circuit for smart water heater
- [ ] Outlet under every sink (water purifier, leak sensor)
- [ ] Outlet at ceiling for motorized curtains
- [ ] Outlet at door entrance for smart doorbell/camera
Low-Voltage
- [ ] Cat 6a to every room (minimum 2 drops per room)
- [ ] Cat 6a to TV wall (3–4 drops)
- [ ] Cat 6a to ceiling AP locations
- [ ] Cat 6a to smart home hub location
- [ ] Cat 6a for doorbell camera
- [ ] Cat 6a for each PoE camera location
- [ ] Spare conduits with pull string everywhere
Structural
- [ ] Reinforced ceiling mount for projector
- [ ] Reinforced wall for wall-mounted smart display
- [ ] Niche in shower for smart controls
- [ ] Equipment rack / cabinet space in distribution area
- [ ] Ventilation plan for equipment rack
Final Verification (Before Wall Closing)
- [ ] Photograph every wall with conduits visible
- [ ] Label both ends of every wire and conduit
- [ ] Test continuity of all network cables
- [ ] Test power to all outlet locations
- [ ] Verify neutral present at all switch boxes
- [ ] Document smart device plan with exact locations
- [ ] Share documentation with future self / next electrician
10. Cost Estimates
Pre-installation Cost Breakdown
| Item | Unit Cost | Typical Quantity | Total |
|---|---|---|---|
| Extra neutral wire to switches | ¥5–10/m | 50–100m | ¥250–1000 |
| Extra empty conduit (20mm) | ¥3–5/m | 30–50m | ¥90–250 |
| Cat 6a cable | ¥2–4/m | 200–400m | ¥400–1600 |
| Network outlet (faceplate + module) | ¥15–30/point | 10–20 points | ¥150–600 |
| Smart switch (zero-fire, per gang) | ¥50–150 | 10–20 switches | ¥500–3000 |
| Smart home hub | ¥200–800 | 1–2 | ¥200–1600 |
| Wi-Fi AP (ceiling, PoE) | ¥200–600 | 2–4 | ¥400–2400 |
| PoE switch (8-port) | ¥300–800 | 1 | ¥300–800 |
| Estimated total (pre-installation materials) | ¥2290–11250 |
Note: These are material costs only. Labor for extra wiring during renovation typically adds 20–40%. The cost of retrofitting after renovation (chasing walls, surface-mount trunking) can be 3–5x higher.
11. Common Mistakes to Avoid
| Mistake | Consequence | Prevention |
|---|---|---|
| No neutral at switches | Cannot install reliable smart switches | Specify "零线到每个开关" to electrician |
| 16mm conduit at switches | Cannot pull additional wires later | Use 20mm minimum |
| No spare conduit | No room for future upgrades | Always run 1 extra empty conduit |
| Cat 5e instead of Cat 6a | Limited to 1 Gbps, no 10G future | Specify Cat 6a minimum |
| Hub in metal cabinet | Zigbee/Thread signal blocked | Use plastic/vented enclosure |
| No network to ceiling | Cannot install ceiling AP | Plan AP locations early |
| No outlet under sink | Cannot power leak sensor/purifier | Add under-sink outlets |
| No curtain motor power | Cannot add motorized curtains later | Run power to curtain track end |
| Wi-Fi hub instead of Ethernet hub | Unreliable smart home network | Hub on wired Ethernet |
| No equipment rack documentation | Future electricians can't trace wires | Label and photograph everything |