These days, everyone's obsessed with home renovations. You see it all over TikTok and Instagram. The open-concept kitchens, bedroom makeovers, walk-in closets, and even hidden doors that lead to secret rooms.

Honestly, I get it, especially if you have a smaller flat. It's only natural that you want to knock down the walls and get the most out of your flat. But...!

HDB has a tedious list of rules and restrictions, many of which people might not know (or pretend not to know).

It sucks, but some of the trendiest reno ideas you want for your flat may be illegal. And if you get caught, you may be looking at fines of up to $5,000. So before you call up your contractor or start a new DIY project, let's go through some of the most common illegal HDB renovations.

Wall hacking is easily one of the most popular renovation moves. There are plenty of reasons why people are drawn to it even though it can be expensive. It opens up the space and gives you more freedom to customise your home layout. It's perfect for those who would rather have a larger, more open living area instead of keeping to the original partitioned layout.

However, not every wall in your flat can be removed, no matter how much you're willing to pay. That's because some walls are load-bearing, meaning they support the structure of the building (not just your flat). If you remove it, there could be structural weakening. Or worse, the whole block may topple like dominoes.

That's why you need to get written approvals from HDB before hacking any walls, especially if you live in older blocks where structural integrity is even more delicate. HDB's main concern is keeping the building safe for everyone, which means you can't do anything that could compromise the structure of the building. This includes hacking, alterations, removal of, or drilling holes through reinforced concrete walls, columns, beams, and slabs among others. On top of that, you also aren't allowed to create openings in existing external walls or do any work that affects the external facade.

Speaking of structural integrity, the floor slab can only safely support up to 150 kilograms per square metre. This means if you're planning to use materials like marble (especially for large items like bed frame or bathtub) or install heavy features like built-in fish tanks, heavy gym equipment, or large storage platforms, you'll have to be extra careful. If not, you might stress the structure, and your floor could collapse!

That's why HDB also won't allow you to raise the floor level by more than 50mm (this includes the thickness of your floor tiles) using concrete. It might seem like a harmless design choice to elevate certain rooms, create a platform bed, or achieve a specific aesthetic. But adding excessive concrete weight increases the load on the floor slab.

Again, safety is non-negotiable, which is why HDB strictly prohibits the use of combustible or toxic-emitting materials for partitioning. This includes materials like plywood, certain types of plastics, or worse, asbestos, which is globally recognised as a serious health hazard.

Just think about it. In the event of a fire, partitions made from combustible materials can cause the flames to spread much faster. What could have been containable can become uncontrollable and potentially fatal. Additionally, some plastics or chemically-treated materials release toxic fumes when burned. These fumes can cause severe respiratory damage, poisoning, or even death.

Ironically, asbestos was used for fireproofing in the past, as well as thermal, electrical and sound insulation. But despite being fire-resistant, when its fibres are disturbed (which may happen during renovations), it can become airborne and inhaled. This poses long-term health risks, including lung cancer, mesothelioma, and asbestosis. For these reasons, asbestos has been banned in Singapore since 1989.

In short, while it may be tempting to opt for cheaper options, it's essential to choose materials that meet safety standards.

If it's outside your door, then it's technically a communal space. So, they are strictly off limits.

For starters, you're not allowed to lay floor finishes outside your entrance door unless there's a recess area or step. Some homeowners like the idea of tiling over the corridor space just beyond their unit for aesthetic purposes. Maybe to match their interior flooring, create a visual boundary, or simply make their doorstep feel more exclusive.

But this is a problem. Not only does it blur the lines between private and communal space, it also poses tripping hazards and obstructs the common pathway used by neighbours and emergency services.

You also cannot paint the external parts of the building, including common corridor walls and ceilings, even if the paint is chipped or outdated. That's the Town Council's job, not yours.

Likewise, you're not allowed to:

• Paint external walls or railings of your balcony in a different colour from the original scheme.
• Install awnings, blinds or other fixtures outside your unit.
• Remove or modify balcony railings as it could compromise fall protection and void compliance with building codes.
• Install overhead grilles at the balcony as it poses potential fire safety risks by limiting escape routes or ventilation.

Safety talk aside, your balcony may feel like your private space, but visually, it's part of the building's facade. If everyone renovates their balcony in a different style, the block would end up looking like a patchwork quilt, and not in a good way.

Basically, these rules keep the estate's aesthetics cohesive and common areas safe and properly maintained.

Windows might seem like an easy feature to customise, but again, they're subject to strict rules for both safety and uniformity reasons.

First, you cannot replace your existing full-height windows, 3/4 height windows, or bay windows on your own. If they are damaged, you'll need to get HDB's permission before getting them replaced.

You also can't replace the window glazing with a different colour or apply reflective window film that exceeds 20% reflectance. Overly reflective films may seem like a good idea for privacy or heat reduction, but they can cause uncomfortable glare and stand out aesthetically.

Similarly, installing window unit air-conditioners comes with its own restrictions. Window units are only permitted on casement or sliding windows, and even then, they must meet installation guidelines from HDB and the Building and Construction Authority (BCA) to prevent the unit from posing a falling hazard.

Lastly, you're not allowed to seal up existing windows, main doors, or Household Shelter openings. These features exist for ventilation, fire safety, and escape access in case of an emergency.

The Household Shelter, better known as the bomb shelter, is one part of your flat you really don't want to mess with. Designed as a protective space in times of emergency, the shelter comes reinforced with steel doors, thickened floors, walls, and ceilings, all of which are considered essential structural elements of your home. That means no hacking, no drilling, and definitely no tampering with its core features.

Any aesthetic upgrades are heavily restricted. For example, while you're allowed to paint the shelter door, you must first strip off any old layers of paint before applying a fresh coat. If you keep painting over existing layers, the door can become too thick, making it difficult to open or close, which defeats its purpose in an emergency. Plus, the door's notice label, locking bolts, and rubber seal must remain untouched and visible, as they contain important usage instructions.

It's also common for homeowners to seal up or remove the ventilation plate covers on the shelter by taking out the supporting stems (see picture above), but there are rules here too. If you do remove them, they need to be reinstalled on one of the shelter's walls using removable screws (max 50mm) with non-metallic inserts. And the original bolts and nuts must be re-secured in their fully closed positions after any adjustments.

HDB does allow you to partially cover the shelter's ventilation opening, but only up to 75%, and the covering must be removable. This is to ensure that airflow remains functional, especially since the shelter needs to serve as a safe haven during emergencies.

And as I've mentioned earlier, you're not allowed to seal up the shelter's door or ventilation openings entirely as this can compromise both safety and functionality

If you're moving into a new Build-to-Order (BTO) flat, you'll need to be extra careful with your bathroom renovation plans. HDB has a three-year restriction on removing the original wall and floor tiles in the bathroom and toilet. This is because beneath these tiles lies a waterproof membrane designed to prevent water from leaking into the unit below. Tampering with it too soon could result in costly leaks and neighbour complaints.

Still, if you're eager to refresh the look of your bathroom, you're allowed to overlay new tiles on top of the existing ones. This method lets you achieve a visual upgrade without compromising the waterproof layer.

Once the three-year restriction period is over, you'll still need to apply for a permit if you plan to enlarge your bathroom space. But even then, there are limits: you can only extend the bathroom by up to 600mm (0.6m) in width, and the total extension area cannot exceed 0.6 square metres. Moreover, the expanded space is strictly for dry use only. So like storage shelves or a wash basin, not a wet shower area.

One more thing. If your unit has a gas riser and branch pipe, you're not allowed to enclose them. It won't be pretty, but these pipes must remain accessible for safety inspections and maintenance.

At the end of the day, we all want to live in a home that feels uniquely ours. A little creativity is great, but when it comes to renovations, HDB doesn't make rules just to spite you. These regulations exist to keep everyone safe and maintain the estate's aesthetics.

Sure, it might feel restrictive. But getting caught for illegal renos could cost you more than just a fine. You'll have to pay to undo the works and even risk voiding your insurance coverage.

So before you start knocking down walls or sneaking in that trendy floor-to-ceiling mirror partition, do yourself a favour. Check the rules, get the proper permits, and engage contractors that are approved on the Directory of Renovation Contractors (DRC).

It's your home, but you're also living in a shared space. So when you break the rules, it doesn't just affect you, but your neighbours too!

If you like this type of content, here's another one for your next read: Rental Rip-offs & Renovation Robberies: Are You Their Next Target?

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