One of the most common questions from Synchronos clients: "We already live in our home. Can we still get smart automation without major construction?" The answer, in most cases, is a clear yes. This guide explains exactly how Synchronos approaches retrofit smart home projects in existing apartments and villas across Bangalore.
What Is a Retrofit Smart Home?
A retrofit installation adds smart home automation to a home that was originally built without smart wiring infrastructure. Unlike new constructions where conduits and bus cables are planned in the walls, a retrofit must work with whatever exists — often 2-wire switches without neutral wires, limited conduit access, and finished wall surfaces that clients don't want to damage.
The Retrofit Challenge: No Neutral Wire
Traditional Indian electrical switches use 2-wire connections (live + switch return). Many smart switches require a neutral wire for continuous power. Several solutions exist:
- Smart switches without neutral: Modern smart switch devices from brands like Legrand Netatmo, Schneider Wiser, and Lutron Caséta are specifically designed for 2-wire connections.
- Micromodule approach: Wireless modules (KNX RF, Zigbee, or Z-Wave) fit inside existing electric boxes behind existing switches — transforming any conventional switch into a smart one without changing switch plates.
- Wireless retrofit switches: Battery-powered or energy-harvesting wireless switches (Enocean, KNX RF) that require no wiring at all — stick to any surface.
Retrofit Technology Options
Option A: Wireless Smart Switches
The cleanest retrofit for apartments. Replace only the switch plates with wireless smart switches. No wall breaking, no cable pulling. Zigbee or Z-Wave smart switches from brands like Sonoff, Shelly, and Aqara offer reliable performance at accessible price points. For premium installations, Lutron Caséta provides exceptional reliability with a proprietary Clear Connect RF protocol.
Option B: KNX RF (Radio Frequency)
KNX RF is the wireless variant of the globally trusted KNX protocol — same intelligence, no wires. Certified KNX RF devices communicate at 868MHz, penetrating walls reliably in typical apartment floor plans. Synchronos has used KNX RF extensively in Indiranagar and HSR Layout apartments where wired installations would require significant construction.
Option C: Smart Micromodules
Compact modules (40mm × 40mm × 15mm) that install inside existing electrical boxes behind current switch plates. They add wireless control and smart scheduling while remaining completely invisible. Manufacturers include ABB, Legrand, and Schneider Electric.
Option D: Smart Plugs + Smart Lighting Bridges
For renters or those wanting non-permanent installations: smart plugs (TP-Link Kasa, Amazon Smart Plug), smart bulbs (Philipps Hue, LIFX), and smart IR blasters for AC and TV control. This approach has limitations (no dimming without specific bulbs, aesthetics) but requires zero permanent modification.
Retrofit Applications by Room
Living Room
- Smart dimmer switches for ceiling and accent lights
- Smart IR blaster controlling AV system, AC, and fan via single app or voice
- Smart plug for lamps, side table lighting
- Motorised retrofittable blind motor (Zemismart, Dooya) on existing curtain tracks
Bedroom
- Wireless smart switch at bedside controlling all bedroom lights and AC
- Smart lock on bedroom door (optional for privacy/security)
- Smart AC controller integrating with existing split AC units via IR
Kitchen
- Smart plug on water heater (geyser) — schedule it to heat 20 minutes before your morning shower
- Under-cabinet smart LED strip lights
- Smart exhaust fan controller
Front Door & Main Entrance
- Video door phone (surface-mounted, no wall breaking)
- Smart lock replacing existing deadbolt
- Smart video doorbell (battery-powered options like Eufy or Reolink require no wiring)
Realistic Expectations for Retrofit
Retrofit installations are 80–90% as capable as purpose-built smart wired installations, with these realistic limitations:
- Range: RF devices may struggle in very large homes or homes with thick concrete walls — signal extenders may be needed.
- Dimming: Wireless dimming requires compatible LED bulbs and may not achieve the smooth 0–100% dimming of hardwired Lutron/DALI systems.
- Aesthetics: Smart switch face plates may differ from existing switches, creating a patchwork look. Premium retrofit switches from Legrand Celiane or Gira address this with design-conscious face plates.
Cost of Retrofit Smart Home in Bangalore
- Basic retrofit (3BHK, wireless lights + security): ₹1.5 – 4 lakh
- Mid-range retrofit (full home, KNX RF): ₹6 – 15 lakh
- Premium retrofit (KNX RF + entertainment + security): ₹15 – 30 lakh
FAQ
Can I retrofit smart automation in a rented flat in Bangalore?
Yes — with landlord permission for any permanent fixtures. Battery-powered wireless switches, smart plugs, and smart bulbs require no permanent modifications and can be removed when you move out.
How long does a retrofit installation take?
For a wireless retrofit in a 3BHK apartment: 2–3 days for installation, programming, and user training. No construction mess, no wall damage.
Will the smart home system work during internet outages?
Well-designed systems work locally even without internet. KNX RF, Control4, and Lutron Caséta all operate on local networks — you may lose remote access during outages but local control (app on local Wi-Fi, physical switches) remains fully operational.
