Short answer: set your renovation budget in four steps. Check published cost ranges for your flat type (Qanvast projects about $50,000 to $60,000 for a 4-room BTO and $70,000 to $81,600 for a 4-room resale flat in 2026). Decide the maximum you can afford. Set aside a contingency of 10 to 15%. Then budget furniture, appliances and other move-in costs separately, because renovation figures usually exclude them.

Step 1: find a realistic baseline

Published figures are a starting point, not a quote. Two useful sets:

Qanvast's 2026 projections, based on project medians on its platform:

  • BTO: 3-room about $40,800 to $52,500; 4-room about $50,000 to $60,000; 5-room about $60,600 to $76,500.
  • Resale HDB: 3-room about $55,000 to $68,300; 4-room about $70,000 to $81,600; 5-room about $80,800 to $98,900.

HomeMatch's estimates, quoted in CASE's homeowner guidebook (accurate as of 2025):

  • BTO: 2-room $15,400 to $31,600; 3-room $32,800 to $51,500; 4-room $40,300 to $62,300.
  • Resale: 2-room $28,100 to $41,300; 3-room $42,900 to $66,600; 4-room $55,700 to $80,400.

The ranges differ because the methods and samples differ. Resale flats cost more mainly because old finishes, wiring and plumbing often need replacing. See our guides to BTO and resale HDB costs for detail.

Step 2: set a maximum, then work backwards

CASE recommends setting a maximum budget boundary once you know the typical range. Work backwards from the money you actually have:

  1. Total funds available for the home (cash and any renovation loan).
  2. Minus furniture, appliances, curtains and lighting fittings.
  3. Minus moving, cleaning and any temporary accommodation.
  4. Minus contingency.
  5. What is left is your renovation works budget.

CASE also suggests matching spend to how long you will stay: if you plan to move in about five years, focus on essentials; if it is your long-term home, durable materials and customised features may be worth more.

Step 3: keep a contingency

CASE's guidebook recommends setting aside 10 to 15% of the budget for unexpected expenses. Older resale flats need the upper end, because hidden leaks, mould or faulty wiring often only show up once works begin. For a $60,000 works budget, that is $6,000 to $9,000 you plan not to spend.

Step 4: allocate by priority

List every category, then rank them. A simple budget sheet:

  • Must do: hacking and masonry, electrical rewiring (if needed), plumbing, waterproofing, flooring.
  • High use: kitchen cabinets and worktop, wardrobes, bathroom fittings, lighting.
  • Comfort: air-conditioning, false ceilings, windows and doors.
  • Finishing: painting, feature walls, decorative carpentry.
  • Outside the works budget: furniture, appliances, curtains, moving.

Carpentry is usually one of the largest lines, so it is where planning pays off. Our guides to wardrobes and carpentry finishes compare the options that drive that cost.

A worked example

Here is how the steps fit together for an illustrative 4-room BTO owner. The numbers are examples, not a recommendation.

  1. Funds for the home: $75,000 in cash set aside after the flat purchase.
  2. Furniture, appliances and curtains: the owner estimates $15,000, leaving $60,000.
  3. Moving and cleaning: $1,000, leaving $59,000.
  4. Contingency at about 12%: roughly $7,000, leaving a works budget of about $52,000.

That works budget sits at the lower end of Qanvast's $50,000 to $60,000 projection for a 4-room BTO. The owner now knows the design has to be fairly restrained: perhaps full carpentry in the kitchen and master bedroom, freestanding wardrobes elsewhere, and vinyl over the existing floor tiles. Doing this sum before meeting designers turns a vague wish list into a brief that firms can price realistically.

If the sum comes out well below the published ranges, it is better to phase the work (essentials now, extras later) than to accept a quote that only fits by leaving things out.

Where to save, and where not to

Good places to save:

  • Less built-in carpentry. Each foot run you remove is a direct saving. Freestanding furniture is often cheaper and moves with you.
  • Laminate instead of veneer or spray paint, keeping premium finishes for one feature piece.
  • Overlaying floors instead of hacking, where the existing tiles are sound.

Places to protect:

  • Wiring, plumbing and waterproofing. They are hidden and expensive to redo.
  • Things you touch every day: worktops, hinges, drawer runners, taps.
  • Licensed trades. Electrical work by an EMA licensed electrical worker and plumbing by a PUB licensed plumber are required in HDB flats anyway.

Plan payments as well as totals

A budget is also a cash-flow plan. CASE advises paying no more than 20% upfront and holding back 5 to 10% until all rectification is done. Map each payment to a month so you know when cash, CPF or loan funds are needed. Our payment schedule guide has more.

Keeping the budget during works

CASE lists the common causes of overruns: hidden issues such as mould, leaks or substandard wiring; changing designs or materials mid-project; and underestimating fittings, finishes or labour. The fixes are to inspect before starting, define a clear scope and avoid changes once works begin, and review invoices and variation orders promptly. Fix the design before you collect quotes, and compare them on the same scope with our quotation guide.

How JIAHOME helps

We design your home first for a fixed fee, never a percentage of your renovation, and give you a quotation listing every item without prices. You can then collect prices on exactly the same scope and see where your budget really goes. Packages start from $800. See our packages.

*This article is general information, not financial advice.*

Last updated 14 October 2026