How retrofit works, in plain words
When your house was wired, each switch box was left with a little room behind the plate. A retrofit uses that space. A small smart module goes in behind your existing switches and connects to the same live and switch wires already in the box. Your ordinary switches keep working by hand, and the module adds app, scene and voice control on top.
Onwords builds these modules in-house, from PCB design to firmware, server and mobile app, for Indian voltage fluctuations and electrical standards. They run on your home WiFi, and in larger homes a hub keeps scenes running locally.
Why Choose Smart Home Retro?
Works with Existing Wiring
Our smart modules fit behind your existing switches, no rewiring required.
Quick Installation
Most homes can be fully automated in just 1-2 days.
Non-Destructive
No breaking walls, no mess. We work with what you already have.
Instant Upgrade
Your home becomes smart without losing its original character.
What You Can Achieve
Transform without rewiring - here's what's included:
Who retrofit is for
Finished homes
Walls painted, false ceiling closed, and no appetite for civil work.
Apartments and older houses
Finished apartments where rewiring is painful, and older houses where civil work is a risk.
People who like their switches
You keep your existing switch style and brand.
A first smart home
Start with the rooms you use most and add the rest later on the same system.
Typical rooms and controls
Entrance and living
- One module can handle 2 ceiling lights, 1 fan and 1 profile or cove light
- One-tap scenes like arrival, movie and night
Bedrooms
- Fan on, off and speed from the app, voice or the wall switch
- Motorised curtains where a curtain track allows it
Kitchen, utility and outdoors
- Appliance modules for geysers and pumps
- Balcony and garden lights scheduled by time or sunset
How a retrofit happens
Four steps, in order, and you stay in your home the whole time.
- 1
Walk the house and check the wiring
We check your switch boards, the WiFi in every room and the health of the existing wiring. You get a plan and a cost before work starts.
- 2
Fit modules behind your switches
Our electrician wires a small module to the wires already in each switch box and closes the plate back the same day.
- 3
Set up the app, scenes and voice
We connect the modules to one app, build scenes like arrival, movie and night, and set up voice control in your language.
- 4
Expand room by room
Add curtains, security, cameras and more rooms whenever you are ready. Nothing has to be torn out to grow.
What to check before you decide
Neutral at the switchboard
Most retrofit modules need both live and neutral. Many older Indian homes have no neutral at the switch box, so we check this at survey stage.
A good home network
Weak WiFi in far rooms shows up as slow or dropped control, so we check the network first and strengthen it where needed.
When retrofit is the wrong tool
Very complex scenes, jam-packed switch boxes or large villas that need rock solid uptime are better served by a panel-based or wired design.
Retro, Wireless or Wired?
One team builds all three, so nobody has a reason to push you onto the wrong one.
Smart Home Retro
Best for: finished homes and a first smart home
Onwords modules behind your existing switches. No civil work, and your switch plates stay as they are.
Smart Home Wireless
Best for: finished homes that want premium touch panels
Z-Wave or Zigbee touch panels and sensors on a central hub. A step up in design and feel, without breaking walls.
Smart Home Wired
Best for: new builds and villas, before plastering
KNX bus cable to every switch and sensor, with the switching done in central panels. Planned in during construction.
Frequently asked questions
Will my normal switches still work after the retrofit?
Yes. The module listens to both the physical switch and the app or voice commands, so parents and household staff can keep using the wall switch as usual.
Does retrofit really mean no breaking of walls?
Yes. The modules sit inside your existing switch and fan boxes, so there is no chasing of channels, no re-plastering and no repainting.
What happens if the WiFi or internet goes down?
Your physical switches keep working. Local control may carry on over the hub, but remote access pauses until your internet returns.
Can I take the modules with me when I shift house?
Yes. An electrician can remove the modules and restore normal wiring. If you rent, get your landlord's written permission before anything touches the wiring.
Related guides
Retrofit without breaking walls
How wireless retrofit works in a finished home.
Retrofit modules, the honest guide
Where modules work and where they struggle.
Smart home for a rented flat
Reversible upgrades that move with you.
Budget Living Homes
Our in-house retrofit modules.
Smart home cost in India
What drives the number, tier by tier.
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