Renovation budget for a 40 m² apartment in Jakarta

[cyclesAndWindow]

A flat contingency feels arbitrary, but setting aside a large general reserve without breaking down the risks is not comfortable either. I’m testing an IDR 4,858,000,000 renovation budget for a 40 m² Jakarta apartment, with internal refurbishment and energy improvements planned but no extension.

The visible finishes are not my main concern. Hidden moisture, failed waterproofing, inaccessible plumbing, electrical replacement or unexpected structural work could disrupt the sequence and consume the reserve quickly. How would you divide contingency between unresolved design choices and concealed conditions? I also want to know what the surveyor, building management and bidders should inspect or open up before prices are fixed.

 

[PatientEmber]

I would not choose contingency as a flat percentage until the IDR 4,858,000,000 is broken into packages. Keep separate allowances for unfinished design decisions and genuinely hidden work. Ask for priced scenarios for failed bathroom waterproofing, inaccessible plumbing and electrical replacement beyond “checks.” The reserve should cover the most credible bad scenario without borrowing money already assigned to finishes.

 

[sailsAndQuill]

Does that figure include design fees, building-management charges, temporary accommodation, appliances and imported materials, or is it construction only? That distinction matters more than the apartment size. Also confirm whether contractors may open inspection areas before tender. If they can only look at surfaces, their exclusions will tell you more than a confident lump-sum quotation.

 

[amara_fable]

Get the building constraints before finalising the programme: permitted working hours, lift protection, debris removal, noisy-work restrictions, water or power shutdown arrangements, and access to shared risers. A contractor can sequence the apartment perfectly on paper and still lose time waiting for management access. I would put those dependencies beside every plumbing and electrical activity.

 

[emery_leases]

“Electrical checks” is too loose for tendering. Define whether the contractor is only testing, or also allowing for the distribution board, damaged wiring, additional circuits, outlets, grounding issues and making good after access. Ask each bidder to state what result would trigger extra work and how that work would be priced. Otherwise the lowest quotation may simply contain the narrowest interpretation.

 

[jade_deals]

For plumbing, ask where the isolation points and shared stacks are, which pipes belong to the apartment, and whether concealed connections can be reached without removing cabinets or bathroom finishes. Photograph and map everything exposed during demolition. The important sequencing point is to test repaired supply and waste lines before waterproofing, tiling or closing access panels.

 

[jade_deals]

One addition to my plumbing comment: moisture staining should not automatically be assigned to your bathroom. It could come from a façade, neighbouring unit, shared pipe or condensation. Ask how the surveyor distinguishes among those possibilities. Repairing finishes before identifying the route of moisture is an easy way to pay twice.

 

[blueprint.solid]

I agree on investigating moisture, but I would be cautious about assuming surveys can remove every unknown. In an occupied apartment building, opening shared areas or another unit may not be possible. The contract therefore needs clear assumptions, exclusions and a process for approving concealed-condition costs. A vague contingency cannot compensate for vague change control.

 

[PlainRiver]

Material timing also affects the sequence. Before demolition, identify anything that must fit fixed openings or concealed services—cabinetry, sanitary items, lighting components and flooring transitions—and ask bidders which selections must be frozen first. If a delayed item blocks measurements or installation, agree whether a local alternative is acceptable rather than leaving the apartment open while everyone waits.

 

[PiaHayes]

Separate government permit questions from building-management approval; they may run on different timelines, and the exact requirements depend on the work and building. Give management a marked-up scope showing demolition, wet-area work, electrical changes and any wall alterations, even if nothing structural is intended. Ask what drawings, deposits, contractor details and inspections they require before approving access.

 

[timo_lowe]

The practical next step is a comparison sheet using identical headings for every bidder: demolition, protection of common areas, electrical, plumbing, waterproofing, finishes, testing, waste removal, approvals, lead times, exclusions and reinstatement. Require quantities or clear assumptions where possible. Then challenge every blank and every “by owner” item. That will reveal whether the current budget is genuinely cautious or merely carrying a large undifferentiated allowance.