Seoul 90 m² studio renovation: contingency and hidden conditions

[theo_cedar]

I have checked the visible finishes and set a preliminary budget of ₩281,800,000, but the concealed work remains difficult to judge. The property is a 90 m² studio in Seoul, and the proposed renovation covers the kitchen, bathrooms, floors, decoration, electrical checks and some energy improvements. There is no planned extension or intentional structural alteration.

My priority is identifying work that would be expensive to undo once new surfaces are installed. In particular, how should I investigate plumbing access, moisture and electrical capacity before accepting a contractor total? I would also appreciate views on sizing separate reserves for hidden defects and design changes, and on what evidence would show that structural work is unnecessary rather than merely excluded from the quote.

 

[knitsAndAtlas]

I would split the reserve rather than use one general contingency: one part for conditions uncovered during demolition, and another for client changes or material substitutions. Ask each bidder to list exclusions explicitly, especially electrical replacement beyond testing, concealed plumbing, moisture remediation, disposal, protection of common areas and making good after access holes. Also request a trade-by-trade sequence showing when long-lead materials must be ordered.

 

[wren_holt]

Is the unit currently occupied, and can plumbing be reached without removing finished surfaces in adjoining areas? Building age and any history of leaks would also change the risk considerably. Before comparing contractor totals, I’d want moisture readings around bathrooms and kitchen, an electrical assessment with the intended loads, and confirmation of whether the energy work affects windows, walls or only equipment.

 

[thread.good]

I’d be cautious about dividing the reserve too neatly. A concealed leak can trigger plumbing, drying, electrical and finish work at once, so separate pots may create false precision. Keep one owner-controlled contingency outside the contractor’s price, but make the contract clear about what evidence and pricing are required before it is used. Permit timing and building access rules should be clarified before fixing the programme, even without an extension.

 

[theo_cedar]

That helps. I’ll keep the ₩281,800,000 as the working scope budget for now and hold the contingency separately rather than letting it disappear into allowances. My next step will be to ask bidders for exclusions, provisional items and a sequencing plan, then arrange targeted moisture, electrical and plumbing-access checks. I’ll also clarify material lead times and any building or permit timing before accepting a start date.