Renovating your HDB flat for the first time is exciting — and overwhelming. You're making decisions about materials, layouts, and contractors while trying to understand HDB rules, permits, and timelines. It's a lot.
This guide covers everything you need to know before you sign a single contract. We've renovated over 500 homes, and the questions homeowners ask us most — we've answered them all here.
Step 1: Understand What HDB Allows
Before you get excited about that open-concept layout you saw on Pinterest, check what's actually permitted. HDB has specific rules about which walls can be hacked, how much flooring can be changed, and what works require permits.
The key categories of works that require an HDB permit include:
- Hacking of walls (structural or non-structural)
- Electrical works beyond minor changes
- Plumbing modifications
- Installation of window grilles or roller shutters
- Any works affecting the building's external facade
A reputable contractor will tell you upfront what's permitted and what isn't — and apply for the permits on your behalf. If a contractor says "just hack it, nobody will check," walk away.
Step 2: Set Your Budget Properly
The most common mistake first-timers make is budgeting too tight with no buffer. A full renovation for a 4-room HDB typically ranges from S$40,000 to S$65,000 depending on finishes and scope. Here's a rough breakdown:
- Hacking and disposal: S$2,000–S$5,000
- Flooring: S$5,000–S$12,000
- Carpentry (wardrobes, kitchen cabinets, TV console): S$12,000–S$25,000
- Kitchen renovation: S$8,000–S$18,000
- Bathroom renovation (2 bathrooms): S$8,000–S$16,000
- Electrical works: S$3,000–S$6,000
- Painting: S$2,000–S$4,000
Always set aside at least 10–15% as contingency. Hidden issues — like old waterproofing failures, outdated wiring, or existing damage behind walls — are common in resale flats.
Step 3: Choose the Right Contractor
Your contractor choice is the single most important decision you'll make. A good contractor finishes on time, communicates daily, and stands behind their work. A bad one disappears mid-project, cuts corners, and leaves you with defects that take months to rectify.
Look for these non-negotiables:
- HDB-approved contractor status (check the HDB directory)
- CaseTrust or RCMA accreditation
- A physical office you can visit
- References from recent clients willing to be contacted
- A clear, itemised quotation — not a one-line "full renovation S$45,000"
Step 4: Understand the Timeline
A full 4-room HDB renovation realistically takes 8–12 weeks. Here's how that typically breaks down:
- Weeks 1–2: Hacking, disposal, and preparatory works
- Weeks 3–5: Tiling, plumbing, electrical rough-ins
- Weeks 6–8: Carpentry installation
- Weeks 9–10: Painting, ceiling works, light fittings
- Weeks 11–12: Final fitting-out, defect checks, cleaning
Don't plan to move in the day the contractor says "done." Give yourself at least a week after handover before you move furniture in — small touch-ups and defect rectifications always happen in that window.
Step 5: Managing During the Renovation
You don't need to be on-site every day — that's your project manager's job. But you should expect daily photo updates, be reachable for quick decisions, and do a mid-project walkthrough at around the halfway mark.
Key things to check during your mid-project visit:
- Tile alignment and grouting quality
- Carpentry fit and finish
- Position of power points and switches
- Waterproofing before tiles are laid in wet areas
What to Do at Handover
Don't rush the handover walkthrough. Take your time and check every room methodically. Look for:
- Tile chips, lippage (uneven edges), or grout inconsistencies
- Cabinet doors and drawers that don't align or close properly
- Paint marks, drips, or uneven coverage
- Switches and sockets that don't work
- Any water flow issues from taps and showers
Every defect you note at handover should be fixed before you make your final payment. A reputable contractor expects this and won't push back.