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Cat-Proofing an HDB Flat: Cat Net vs Invisible Grille vs Mesh Screens
A practical comparison of cat nets, mesh window screens and invisible grilles for HDB flats, with the HDB and AVS rules that apply and typical Singapore prices.
- Since 1 September 2024 you can keep up to two cats in an HDB flat, licensed and microchipped.
- Use mesh screens on windows you open daily, a cat net where you need airflow, and mesh on the main gate.
- Invisible grilles stop falls but a kitten may slip through, and they cost about $440 to $572 depending on the room.
- Homey fits nets and mesh inside the window frame, but does not install invisible grilles or alter windows.
Homey Furnishing 8 min read Photo: Manabu Itoh, CC BY-SA 2.0, via Wikimedia Commons.
Your cat sleeps on the bedroom sill of a 12th-storey HDB flat, the casement is open for the breeze, and one moth is all it takes. To cat proof an HDB flat you need a physical barrier on every window, ledge and gate the cat can reach, and for most flats that means fitted mesh screens on windows you open daily, a cat net where you need the most airflow, and mesh on the main gate. Invisible grilles stop falls well, but the cable gap can still let a small cat or kitten through, and they cost more.
Since 1 September 2024 cats have been allowed in HDB flats, and the rules that came with that change expect owners to put barriers up. The sections below compare the three options, set out what HDB allows on windows, and give typical Singapore prices.
What AVS expects from cat owners in HDB flats
The Animal and Veterinary Service (AVS), part of NParks, finalised its Cat Management Framework on 11 May 2024 (NParks, AVS announcement). The points that affect an HDB household:
- Up to two cats are allowed per HDB flat, alongside the existing limit of one dog of an approved breed.
- All pet cats must be licensed and microchipped. The transition period ran from 1 September 2024 to 31 August 2026, so it has now ended.
- First-time licence applicants must complete a free online pet ownership course.
- Owners must keep cats in a safe environment, and the announcement names "installing mesh, grilles, screens, or other barriers" to stop cats roaming or falling from height.
Window protection is now part of the cat-keeping rules AVS set out, so sort it out before the cat moves in.
Cat net vs mesh screen vs invisible grille
The three products do different jobs. A cat net is soft netting (usually polyethylene or nylon) fixed across an opening. A mesh window screen is a framed panel of pet-grade mesh that sits inside the window frame and is held by magnets, hook-and-loop tape, a roller or a hinge. An invisible grille is a row of tensioned stainless steel cables in an aluminium track, drilled into the wall or frame.
| Cat net | Mesh window screen | Invisible grille | |
|---|---|---|---|
| What it stops | Cats and falling objects. Mosquitoes only if the net is fine. | Cats, and insects if the mesh is fine enough | Falls. A small cat or kitten may fit between cables. No insect protection. |
| Look | Visible netting, can sag over time | Neat framed panel, slightly darker view | Thin lines, clearest view |
| Airflow | High | Slightly reduced | Full |
| Typical Singapore price | DIY mesh about S$15 to S$25 per window; installed balcony netting from S$800 | DIY pet screen from S$89 (1m x 1m); custom retractable screens S$400 to S$3,000 per job | From S$8 per sq ft, or S$440 to S$572 depending on the room |
| Rental-friendly | Yes, with removable fixings | Yes, most come off without damage | No, it is drilled in. Get the landlord's consent. |
Price sources: DIY mesh per window from Pawrenthood (March 2026); balcony netting, retractable screens and InnoStruct grilles from MS News (February 2026); the S$89 DIY screen from Magnetic Screens; per sq ft grille pricing from Home & Decor (February 2025). These are typical Singapore prices, not quotes. Window size, number of openings and access all change the figure.
My working verdict for a typical 4-room BTO is this. Choose mesh screens for bedroom and living-room windows you open every day, because they also keep mosquitoes out and come off for cleaning. Choose a cat net for the service yard or a kitchen window that stays open for ventilation. Choose an invisible grille only if you want an unobstructed view and you have checked the cable gap against your smallest cat. Skip the grille if you rent.
Photo: Jamie McCaffrey, CC BY 2.0, via Wikimedia Commons.
Why spacing beats strength
Vendors quote breaking loads, but a cat rarely breaks anything. It squeezes. A cat that gets its head through a gap can usually get its body through. Ask any installer for the exact gap in millimetres and hold your hand or a ruler against a sample. With grilles, check the corners and the hinge side of openable panels, where gaps are often wider than the cable spacing.
Cats also chew and claw. Soft netting near a favourite sleeping spot will fray faster than you expect, so check it every few months.
What HDB allows on windows and ledges
HDB's window works guidelines treat grilles differently depending on where they go and when your block was handed over (HDB, window works):
- Internal metal grilles of any design at windows and balcony parapets do not need a permit. For developments handed over before 1 July 2007, they must be fixed internally and must not protrude from the building facade.
- Grilles at a service yard or balcony parapet do need a permit. For flats handed over from 1 July 2007, they must follow HDB-approved designs, which are listed in your renovation factsheet and on MyHDBPage.
- Any window replacement needs a permit and a BCA-approved window contractor listed with HDB.
HDB's list of disallowed works (HDB, important information on renovations) includes overhead grilles (caging up) at an interaction balcony, solid metal external grilles at a planter box, external grilles on an air-conditioner ledge, and removing or tampering with safety railings or grilles HDB originally provided. If you have grilles on a recessed window ledge, you are responsible for their stability and for cleaning the gap behind them.
HDB does not have a separate page for soft cat nets or framed mesh screens. The safe reading of the rules is to keep everything inside the unit and inside the window frame, fix nothing to the outside of the building, and leave the window itself untouched. For balconies and service yards, check your flat's factsheet on MyHDBPage before you put up anything permanent. A neighbour's setup is not approval.
Two practical limits apply as well. HDB says fasteners in walls must not exceed 6mm in diameter and 40mm in penetration depth. And you must check your windows every six months under BCA rules (HDB, windows), so a screen must not stop the casement from closing fully or put weight on its hinges and rivets.
Walk the flat the way the cat does
Before buying anything, stand in each room and trace the route to every opening:
- Bedroom windows next to the bed or a dressing table.
- Living-room windows behind a sofa or console.
- The service yard window, often left open for laundry.
- Kitchen windows reachable from the counter or the top of the fridge.
- The main door and gate, especially during deliveries.
Move furniture away from windows before adding barriers, because a bookshelf next to a mesh screen gives the cat a platform to claw from. Then decide which windows must stay openable for cleaning and emergency exit.
Gates and doors
The main door is the other common escape route. A standard HDB metal gate has bars spaced wide enough for a cat to walk through. Mesh fixed to the inside face of the gate closes those gaps without changing the gate itself. Custom mesh gates typically cost S$80 to S$200 (Pawrenthood). Inside the flat, a mesh panel on a bedroom or kitchen doorway gives you a second barrier when contractors or guests come and go.
What Homey installs
Homey is a general handyman and furnishing shop, not a window contractor. We fit cat nets and mesh window screens within the window frame, mesh on main gates and doors, and indoor barriers. We do not replace or alter windows (that needs a BCA-approved window contractor), we do not fix anything to the outside of the building, and we do not install tensioned cable invisible grilles. If you want a grille, use a grille specialist, and you can still have us mesh the gate and the windows the grille does not cover.
Common quote traps to watch for:
- A price per window with no sizes written down.
- "Pet-safe" with no mesh or gap size stated.
- No mention of which panels stay openable.
- Netting quoted for a balcony without anyone checking your block's guidelines.
FAQ
Are cats allowed in HDB flats now? Yes. Under AVS's Cat Management Framework, which began on 1 September 2024, you can keep up to two cats in an HDB flat, and every pet cat must be licensed and microchipped.
Do I need an HDB permit to install a cat net or mesh screen? HDB says internal grilles at windows do not need a permit, and it has no separate rule for nets or screens, so keep them inside the unit and within the window frame. Grilles at a service yard or balcony parapet do need a permit and, for flats handed over from 1 July 2007, an approved design, so check your factsheet first.
Is an invisible grille enough to cat proof a window? It stops falls, but a small cat or kitten may slip between the cables. Ask for the exact gap, check it against your smallest cat, and add mesh where the gap is too wide.
Can I cat proof a rented HDB flat? Yes. Magnetic, hook-and-loop or tension-fit mesh screens and removable nets come off without damage. Get the landlord's written consent before anything is drilled.
How much does it cost to cat proof an HDB flat in Singapore? DIY mesh starts at about S$15 to S$25 per window. Installed custom screens are typically S$400 to S$3,000 depending on how many windows you do, and a mesh gate is typically S$80 to S$200.
To get a quote, photograph each window from inside (frame corners and handles in shot), the service yard, the main gate, and the spot where your cat likes to sit. Note whether the window is casement or sliding and which ones you open daily, then send it through our pet proofing service.