Interior Contract Checklist in Korea: Quotes, Payments, Warranty

Most interior disputes in Korea are seeded before the contract is signed, not during construction. The quote says only "lump sum", so no one knows what is included; too much money is paid up front and work stalls; or demolition reveals "that was never in this price" and extra charges appear. This guide is a step-by-step checklist to run before you sign. Amounts refer to the October 2026 price table behind the K Real Estate remodeling estimator. It is general information, not legal advice, so for a large contract take professional advice as well.

Step 1: Fix the scope before asking for quotes

If every contractor quotes on different terms, you cannot compare prices. Decide first:

• Which trades you want (demolition, windows, electrical, bathrooms, kitchen, tile, wallpaper, flooring, lighting)
• The material grade for each trade (basic, standard, premium); see how to choose material grades
• Whether the work is done in an empty unit or while you live there (living there adds about 8% to labor and about 30% to the schedule)
• Your preferred start date and move-in deadline

Then run the same conditions through the remodeling estimator to get a rough range. For example, a standard full remodel of an 84㎡ unit with two bathrooms in Gyeonggi·Incheon is about KRW 53.81M–73.02M including overhead and VAT. If a quote lands well below the low end of that range, find out what is missing (demolition and disposal, overhead, VAT and so on) before you celebrate. The calculator gives a reference estimate, so the point is to ask the contractor to explain the difference item by item.

Step 2: Line up the quotes item by item

Comparing totals fails. Match each line:

Vague phrases such as "lump sum", "to be discussed" or "depending on site conditions" are doors to extra charges. Ask to replace them with a price cap or a unit price list. The line-item table in the 84㎡ remodeling cost guide helps with comparison.

Step 3: Check the contractor

• Business registration and track record: confirm the business registration certificate shows the same company name and representative as the contract, and ask to see similar projects and finished sites.
• Interior construction license: in Korea, finishing work inside buildings falls under the "interior construction business" (실내건축공사업) category of the construction industry, and work above a certain size must be done by a registered company. The threshold for minor work is set by law and can change, so check the Enforcement Decree of the Framework Act on the Construction Industry at the National Law Information Center and ask the contractor for a copy of its registration.
• Insurance and guarantees: ask whether the contractor carries insurance that can compensate neighbors or the unit below for accidents and leaks, and whether a defect warranty guarantee is available.
• Subcontracting: ask who will actually do the work and whether trades are subcontracted.
• Account name: the account you pay into should match the company or representative named on the contract. If not, get the reason in writing.

Step 4: Split payments into deposit, interim and balance

Pay in installments tied to progress. There is no legally fixed ratio; it is negotiated, so the table is only an example.

• A demand for half or more up front is a warning sign. If it is for pre-ordered materials, get the material list and amounts in writing.
• Add a clause that the balance is paid after the defect inspection. Paying the balance early weakens your leverage.
• Write down the refund rule if you cancel after paying the deposit but before work starts.
• Take receipts as a tax invoice or cash receipt. A cash-only deal to avoid VAT makes it hard to prove the contract in a dispute. Whether remodeling costs count as deductible expenses when you sell the home should be checked with the tax calculator and a tax accountant.

Step 5: Special clauses worth adding

If the standard contract lacks these, add them as special terms or attachments.

1. Material specification sheet: attach brand, model, color and quantity, and state "only equal or better, changed only with written consent".
2. Schedule and delay responsibility: write start and completion dates and key milestones, and set how delay compensation works if the delay is the contractor's fault.
3. Defect repair: set the repair period, how to report, and the deadline to complete repairs (for example, within a number of days after notice). Waterproofing and plumbing, whose problems appear late, deserve a longer period than wallpaper and finishes. Statutory warranty periods differ by trade, so check the law.
4. Extra or changed work: only after written agreement, priced at the quote's unit prices.
5. Waste, protection and cleaning: define who handles waste disposal, elevator and hallway protection, and move-in cleaning.
6. Management office filing and complaints: write who files the notice and who handles neighbor complaints. The procedure is covered in remodeling order and timeline.
7. Damage and accidents: state that the contractor is responsible for damage to neighbors or common areas and for your existing furniture and appliances.
8. Termination: list the grounds for either side to terminate and how completed work is settled.

Step 6: Prevent extra-cost disputes

Extra costs usually come from three places.

• Items left out of the quote: demolition waste, protection, threshold finishing, silicone sealing and move-in cleaning are typical. Confirm each one before signing.
• Problems found after demolition: corroded pipes, leak traces and uneven floors only show up once things are opened. A separate 10% contingency softens the shock.
• Changes made midway: swapping materials during work creates a price difference. Get the difference in writing before the change.

The rule is simple. Treat verbal promises as nonexistent and record every change in a document with date, amount and signature. Messenger chats also count as evidence, but it is safer to write in the contract that changes are confirmed in writing or by text message.

Step 7: Inspect during work and at completion

• Ask for photos of every trade and visit the site yourself right after demolition, waterproofing and rough wiring.
• After waterproofing, ask for the result of the flood test, where the floor is filled with water to check for leaks.
• At the completion inspection, test every faucet, drain, light, switch, door and window lock, and list defects with photos.
• Pay the balance only after the defect list is handled, and keep the after-service contact and warranty papers.

More stage-by-stage checks are in remodeling order and timeline.

If a dispute arises

First record the problem with photos and messages and demand correction from the contractor in writing (text or email, or certified mail if needed). If that fails, call the Korea Consumer Agency hotline 1372, or ask the Korea Legal Aid Corporation if cost is a concern. You can also find legal help through legal expert matching. If you are still choosing a contractor, post the same conditions on remodeling contractor matching and compare several quotes.