Hidden Costs When Renovating Older Flats (That Catch First-Timers Off Guard)

Renovating an older resale flat in Singapore can be exciting but also unexpectedly expensive.

While the initial quote may seem manageable, first-time homeowners often find themselves

blindsided by additional costs once the work begins. These surprises usually don’t stem from bad planning or budgeting - it’s simply that older flats

come with aged infrastructure, concealed issues, and unique quirks that only surface

mid-renovation. If you're thinking of investing in a resale renovation, this guide will help you

prepare for the hidden costs that many first-timers overlook.

1. Electrical Works – More Complex Than You Think

Older flats weren’t designed to support today’s power-heavy lifestyles. Rewiring a flat to handle air-conditioners, ovens, heaters, and smart devices is often necessary.

But the bigger cost surprise comes when you want power sockets or lighting in

unconventional locations. For example, under a kitchen island, inside a wardrobe, or on the

ceiling for a projector setup.

In older HDB units, concealed wiring is sometimes not possible due to wall structure or

regulations, which means surface trunking (less aesthetically pleasing) or hacking walls (which costs more).

Expect to pay extra if your ideal layout requires extensive rewiring or creative electrical

rerouting. Always clarify this early with your renovation interior design partner so you can plan around it.

2. Plumbing Surprises and Water Damage Risks

One of the most common hidden costs in older flats? Plumbing. Even if taps and toilets seem to work fine, old pipes made of cast iron or galvanised steel may be corroded inside. Once renovations start like hacking floors or retiling bathrooms: leaks, clogs, or pressure issues often reveal themselves. Redoing the plumbing for a toilet or kitchen can easily cost several thousand dollars, especially if your contractor discovers problems mid-renovation.

Even worse, if water seepage is coming from your upstairs neighbour’s unit, you’ll need to

work with them to resolve the issue. If they’re uncooperative, expect delays, stress, and

potential legal grey areas. It’s best to inspect for water damage before buying the unit, and

again before works begin.

3. Fixtures and Fittings That Add Up Quickly

Even seemingly small items like door frames can deliver sticker shock. Replacing a single HDB door frame? That’ll cost you $600 to $900 per frame, and older flats often have more doors than modern layouts. Multiply that across your entire home and the cost adds up quickly, especially if you’re going for uniform design or custom carpentry.

Other overlooked expenses include:

● Window grilles or full frame replacements (required in some older units)

● New plumbing fixtures and tap points

● Kitchen backsplash or tiling not covered in basic packages

These aren’t typically included in base resale renovation package quotes, so be sure to check what’s covered.

4. Cost of Unforeseen Rectification Work

Sometimes, things go wrong after renovation begins. You might discover:

● Spalling concrete behind walls

● Unlevel flooring that affects new vinyl overlays

● Termite-infested wooden skirting or cabinets

Handling these issues requires extra labour, materials, and sometimes permits, all of which

add to your renovation timeline and cost. For older flats, it’s wise to buffer 10–20% of your

renovation budget for such contingencies.

5. Design Revisions That Add Cost

As a first-timer, your needs may evolve as you see your space take shape. Adding a feature

wall, relocating a sink, or changing a lighting layout mid-way can incur variation orders

(VOs) which are chargeable adjustments to your contract.

In older flats, these changes tend to be more costly, because reconfiguring old infrastructure is trickier than working with a blank slate. Don’t Let Surprises Derail Your Renovation The truth is, resale renovation in older flats will almost always come with surprises. But that

doesn’t mean you need to go over budget. It just means planning smarter and working with

an experienced team.

Renovating an Older Flat? Let’s Help You Budget Wisely.

At Hamid and Sons Interior, we’ve completed over 50,000 renovation projects since 1980,

many of them in older resale flats. Our expert team knows where hidden costs tend to creep

in and how to help you avoid or minimise them.

From thorough pre-renovation inspections to fully customised renovation packages, we’re here to turn your vision into a stress-free reality.

Get in touch with Hamid and Sons Interior today and let’s create a renovation plan that works

for your space and your wallet.