HDB household shelter renovation rules: floors, drilling, doors and vents

An HDB household shelter may spend most days as a storeroom, but it is not an ordinary room. Its walls, floor, ceiling, door and ventilation components form a protective system. A neat renovation can still be non-compliant if it uses the wrong floor finish, drills too deeply or blocks the door or ventilation sleeves.

This is the shelter-specific companion to our HDB renovation permit guide. That guide covers the wider HDB process; this article translates SCDF's shelter-specific limits. Verify the exact flat and work scope against the latest documents before ordering finishes or drilling.

Start with the two official rule sets

SCDF's current civil defence shelter requirements hub links to its technical requirements and homeowner documents. Keep the two-page permitted and not permitted works for household shelters PDF with the renovation drawings; it is the source for the limits below.

Then check HDB's renovation hub for the wider rules and permit path. SCDF permission does not settle every HDB or trade requirement, and a general renovation approval does not override the shelter limits.

The quick household shelter rules table

Flooring: build-up matters more than the surface colour

SCDF permits floor tiles inside a household shelter when they are bonded with wet cement mortar. The combined thickness of the floor finish and screed must be no more than 50mm. Skirting tiles may also be bonded to shelter walls with wet cement mortar, up to100mm high. Vinyl and linoleum flooring are expressly listed as permitted.

Floor tiles laid with adhesive materials are not permitted, and neither is a second layer of floor or skirting tiles. An overlay is not automatically acceptable because it avoids hacking. Ask the contractor to show the existing screed, bedding and final finish thickness before ordering.

Internal walls are different. Wall tiles, rock-tone or cement-sand finishes, gypsum plaster and internal cornices are not permitted. Use compliant paint and removable storage instead.

Painting the shelter door needs a careful method

Painting the shelter walls, ceiling or door is allowed, but the door is not an ordinary metal door. Its notice, locking bolts and door seal must not be painted over or covered. SCDF also says the old paint coat on the door and frame is to be removed before repainting so layers do not build up and make the door difficult to open or close.

Let the new coat dry completely before closing the door so damp paint does not stick the gasket to the frame. Put protection of sensitive parts and a final movement check in the painter's scope. Modifying, removing or tampering with the door and frame is not permitted; seek flat-specific guidance if either appears damaged.

Drilling and internal storage: removable really means removable

SCDF permits controlled drilling into the internal face of shelter walls and ceiling slabs to no more than 50mm deep for non-metallic inserts and removable screws. The insert must not exceed 50mm in length. This does not allow exploratory holes, chasing or hacking.

Pictures, posters, cabinets and shelves fixed to the internal face must be removable by the owner within 48 hours of notification. Design for that from day one: avoid storage that traps other units or needs demolition to dismantle, and keep the removal tool and fixing plan.

Power-driven nails are not permitted on internal shelter walls. They are allowed only on the external face of shelter walls, with a maximum length of 75mm. The internal and external faces can be confused after carpentry conceals the outline, so mark the shelter footprint and fixings on the contractor's drawing.

Ventilation openings must stay usable and accessible

A decorative panel may cover the household shelter ventilation openings only when the finish is removable. At least 25% of the combined area of the two openings must stay uncovered during peacetime. Do not permanently seal one behind carpentry and leave a token gap elsewhere.

SCDF's document also sets clearances around the fragmentation plate: at least 50mm from the plate to a structure or service, and at least 500mm clear where a structure or service sits in front of it. If a false ceiling is installed outside the shelter and below the ventilation sleeves, provide a perforated access panel at least600mm by 600mm directly below each sleeve.

Do not modify or tamper with the ventilation openings, plates, bolts, nuts, gaskets or mounting devices. Design covers, ceilings and cabinets around intact hardware, the required airflow and quick access. Check any proposed handling of a fragmentation plate against the current official document rather than treating it as alteration permission.

Work that should be an immediate stop

These proposals conflict with SCDF's household shelter list and should not appear as an informal variation on site:

• wall tiles, rock-tone spray, cement-sand finish or gypsum plaster on internal shelter walls;
• floor tiles fixed with adhesive materials, or a second layer of floor or skirting tiles;
• cornices installed inside the household shelter;
• power-driven nails used on internal shelter walls;
• indiscriminate hacking or drilling of the walls, floor slab or ceiling slab;
• hacking either wall face to create a key for tiles, or hacking the external face to mount panels or wall tiles;
• covering or removing the door notice, or modifying the door and frame;
• altering the ventilation openings, plates, sleeves, bolts, nuts, gaskets or other mounting hardware.

If completed work appears on that list, do not test a remedy by hacking, drilling or dismantling more parts. Photograph the condition without disturbing it, gather the renovation drawings and invoices, and ask the relevant authority and a suitably competent party what rectification is required for that flat.

A better way to brief your renovation contractor

Treat the shelter as its own drawing package instead of one line marked "storeroom carpentry". Before work starts, ask for:

1. A floor build-up: existing condition, screed, bonding method, finish and total thickness.
2. A fixing schedule: internal or external face, item weight, fixing type, hole depth and how the item comes down.
3. A door-paint method: old-coat removal, protection of the notice, bolts and seal, plus drying time before closure.
4. A ventilation detail: removable cover, calculated open area, clearances and access to every component.
5. A ceiling detail: the location and clear size of each perforated access panel below a ventilation sleeve.
6. A handover record: photos of exposed components, fixing locations, removal tools and the latest source documents used.

For a new flat, settle the shelter plan after your HDB handover inspection before finishes hide the original condition. Our BTO renovation service can coordinate the wider scope around those constraints. For an older home, first record existing finishes, fixings, door operation and vent access; our resale renovation service starts with the current site condition rather than assumptions.

What SparkFlow can—and cannot—scope here

SparkFlow can plan a wider HDB renovation around the shelter and document proposed finishes. We do not offer structural shelter work, door or frame modification, or ventilation-hardware alteration as ordinary renovation services. This guide is not approval for any of them.

Send the floor plan, clear photos of all shelter faces, the door and both ventilation openings, plus the proposed floor, paint, storage and ceiling details through our renovation service. We can separate ordinary renovation coordination from work needing authority guidance or another competent party. Before quoting and site work, verify the flat-specific scope against the latest SCDF documents, HDB rules and permit conditions. This is a poor place for a "should be okay" assumption.