Cost of Chimney and Hob Installation with Civil Work in a Kolkata Kitchen
Most homeowners we meet in New Town and Salt Lake have already priced the chimney and hob itself, a decent 60cm auto-clean chimney with a matching four-burner hob runs somewhere between ₹28,000 and ₹65,000 depending on the brand, but almost nobody has priced the civil work that has to happen around those two appliances before either one can actually be switched on, and that civil and ducting package typically adds another ₹6,000 to ₹16,000 to the project depending on how far the exhaust has to travel and what the existing wall and countertop are made of. We handle this civil work on nearly every modular kitchen we execute in Kolkata, and separating the appliance cost from the installation cost is the single clearest way to understand why two quotations for the "same" kitchen chimney can differ by ten or fifteen thousand rupees.
What Civil Work Actually Means for a Chimney and Hob
The chimney and hob themselves are factory-made appliances that arrive boxed and ready to mount. Civil work is everything the site team has to do to make your specific kitchen, with its specific wall thickness, its specific distance to an external wall, and its specific countertop material, accept those appliances cleanly. For a chimney, that means cutting an opening through the wall for the exhaust duct, routing an aluminium or GI duct pipe from the chimney outlet to that opening, boxing the visible run of duct in MDF or plywood so it does not look like a pipe hanging across your kitchen, and fixing an external cowl and non-return flap on the outside wall to stop insects and rain from coming back through the duct. For a hob, civil work means cutting an accurate opening in the countertop, whether that is granite, quartz, or a laminate-topped surface, and extending the gas line and an electrical point to the exact spot the hob sits.
Chimney Ducting Cost: Straight Run vs Routed Through a Boxed Channel
If your kitchen has an external wall directly behind the chimney position, ducting is straightforward, a short straight run of aluminium flexible pipe through a single wall opening, and the civil cost for that configuration typically runs ₹2,500 to ₹5,000 including wall cutting, the exterior cowl, and sealing. The complication comes when the kitchen is interior to the flat, which is common in New Town and Rajarhat towers where the kitchen sits away from the building's outer face, and the duct then has to travel horizontally, sometimes six to ten feet, boxed above the overhead cabinets or through a section of false ceiling, before it reaches an exterior wall or a shared exhaust shaft. That boxed run costs ₹150 to ₹350 per running foot depending on whether it is finished in plain MDF or laminate matched to your cabinetry, and a ten-foot routed duct can easily add ₹2,500 to ₹4,000 over a straight run.
Wall cutting cost itself depends on what the wall is made of. Cutting a clean circular or rectangular opening through a standard 4 to 5 inch brick partition wall costs ₹800 to ₹1,500 with a core cutter, but if the exhaust has to pass through a 9 inch external load-bearing wall or a section of RCC, the labour and equipment cost rises to ₹1,800 to ₹2,500, and in a few older South Kolkata buildings we have had to bring in a diamond core cutting machine specifically because standard tools could not get through the wall cleanly without cracking the plaster on either side.
| Feature | Straight Duct to External Wall | Routed Duct Through Boxing |
|---|---|---|
| Typical civil cost | ₹2,500 to ₹5,000 | ₹5,000 to ₹9,000 |
| Duct run length | 2 to 4 ft | 6 to 10 ft |
| Wall cutting needed | One external wall opening | One opening plus possible false ceiling notch |
| Visual result | Minimal boxing visible | Full boxed channel needs cladding to match cabinetry |
| Best suited for | Kitchens on the building's outer face | Interior kitchens away from an exterior wall |
Hob Cut-Out and Countertop Civil Work
Cutting a hob opening into an installed countertop is precise work, and the cost varies by material. A granite countertop cutout costs ₹1,500 to ₹2,500 since granite cuts relatively easily with a standard diamond blade, while quartz, which is harder and more prone to chipping at the edges if the cut is rushed, costs ₹2,200 to ₹3,500 for the same job. Beyond the cut itself, the hob needs its own gas line extension from the main kitchen gas point, which we always insist on having done by a licensed gas fitter rather than the carpentry team, and that typically adds ₹800 to ₹1,500, plus an electrical point for the hob's ignition and safety sensor, which is another ₹400 to ₹800 depending on whether new wiring has to be pulled through the cabinet carcass.
Appliance Price vs Installation Price: Why Quotations Split Them
We deliberately quote the chimney and hob appliance cost separately from the civil and installation cost, because bundling them into one number hides where the money is actually going and makes it hard to compare one contractor's quotation against another's. A showroom or online listing price for a chimney only ever covers the box that arrives at your door. The moment that chimney has to be mounted above your specific hob, connected to ducting that fits your specific kitchen layout, and wired into your specific electrical points, you are paying for site-specific labour and materials that no catalogue price can capture. When a quotation looks unusually low, it is worth asking directly whether wall cutting, duct boxing, the exterior cowl, and the countertop cutout are included, because those line items are exactly where corners get cut.
| Item | Typical Cost Range | Notes |
|---|---|---|
| Chimney (60cm, auto-clean)," | ₹18,000 to ₹45,000",Appliance price only | |
| Hob (4-burner glass top)," | ₹10,000 to ₹20,000",Appliance price only | |
| Wall cutting for duct," | ₹800 to ₹2,500",Depends on wall thickness | |
| Duct boxing (per running ft)," | ₹150 to ₹350",For routed installations | |
| Exterior cowl and flap," | ₹1,200 to ₹2,000",Fixed cost | |
| Countertop cutout for hob," | ₹1,500 to ₹3,500",Granite lower, quartz higher | |
| Gas line extension," | ₹800 to ₹1,500",Licensed fitter only | |
| Electrical point for hob," | ₹400 to ₹800",New wiring if required |
Where This Trips Up NKDA and Society-Governed Flats
In several New Town and Salt Lake towers we have worked in, the housing society or the building's façade guidelines restrict where an exterior exhaust cowl can be placed, particularly on units that face the main road elevation, which means the duct sometimes has to be routed to a shared exhaust shaft instead of straight through an external wall. This is worth checking with your society or facility management before finalising your kitchen layout, since a shared shaft connection can change both the duct run length and, occasionally, requires a no-objection confirmation from the building management. For any renovation that also touches the flat's overall floor plan or requires structural changes, that broader approval sits alongside the same class of civil compliance our team handles for NKDA, KMC, and Bidhannagar Municipal Corporation jurisdiction projects, chimney ducting itself is minor civil work, but it is still work that has to respect the building's approved services layout.
- Ask your contractor for wall cutting and duct boxing as separate line items, not bundled into "installation"
- Confirm the duct material, aluminium flexible pipe is standard, avoid unbranded thin-gauge alternatives
- Check whether the exterior cowl and non-return flap are included
- Get the gas line extension done only by a licensed fitter with a leak test certificate
- Confirm the countertop cutout is measured against the actual hob model, not a generic size
- Ask whether your society restricts exterior duct or cowl placement on your building's facade
The Rest of the Kitchen Budget
Chimney and hob civil work is one piece of a larger modular kitchen number, and if you have not yet worked out the full picture, our modular kitchen cost guide for Kolkata covers carcass material, shutter finish, and hardware pricing in the same level of detail. Once the kitchen is sorted, most of our clients move next to the living room, where a custom TV unit spanning a 14 ft wall is often the next big carpentry decision, and if your entrance door faces Kolkata's monsoon directly, it is worth reading our piece on main door materials that don't swell on a monsoon-facing entrance before you finalise that order too. We have also detailed glass versus MS staircase railing costs for a duplex, which tends to come up around the same budgeting stage for larger units.
Get an Itemised Chimney and Hob Quotation for Your Kitchen
If you would rather see the exact wall cutting, ducting, and countertop numbers for your own kitchen instead of working from ranges, send us your kitchen layout and we will walk through the civil work line by line before any appliance gets mounted. Reach out to Studio Contour and we will have a clear, itemised quotation back to you.