Should the old house be repaired or should it be demolished and rebuilt? Help you make key decisions from the perspective of "structural safety", "pipeline life" and "budget CP value"

The crossroads between life and house: repair vs. renovation

In Taipei, buying or inheriting an old apartment that is 30 or 40 years old is a living reality for many people. Faced with mottled walls and outdated kitchens and bathrooms, the first big question is: "Should I spend money to tidy it up, or should I tear it all down and redo it all?"

There is no standard answer, but there is a clear decision-making logic. If you make the right decision, your money will be spent wisely in exchange for safety and comfort; if you make the wrong decision, you may fall into the money pit of "always repairing, always breaking". Let us analyze it from several key aspects.

Evaluation aspect 1: Building structural safety (this is a "one-vote veto" project)

Structural safety is fundamental and there is no room for compromise. Before deciding on any renovation, an assessment must be made:

• Visible signs of danger: There are obvious 45-degree diagonal cracks in the beams or columns, large chunks of concrete are peeling off and the steel bars are severely exposed and corroded, and the floor slabs have a sinking feeling. If these conditions exist, you must immediately ask a structural technician or civil technician for professional appraisal. This is beyond the scope of general decoration and is a structural reinforcement project.
• Common “sea sand house” or “high chloride ion” buildings: This is not uncommon among houses built in the 1980s and 1990s. It is characterized by neutral concrete and often rust stains and cracks on the ceiling. The cost of repairing a sea sand house is extremely high. The usually recommended treatment method is to "remove all the concrete, retain the steel bars and re-grouting", which is almost a reconstruction. If it is confirmed to be a sea sand house and the budget is limited, partial repairs are of little significance.
• Conclusion: If a house has serious structural concerns, you have only two options: 1. Invest heavily in formal structural reinforcements (which are expensive). 2. Give up comprehensive renovation and only do the most basic safety maintenance and simple daily function updates. At this time, the CP value of "comprehensive renovation" is extremely low.

Assessment aspect 2: The status of water, electricity, pipelines and waterproofing systems

If the structure is generally safe, the next step is to look at the "blood vessels and nerves" of the house - the water and electricity pipelines.

• Circuit system: Open the distribution box and check. If it is an old "knife switch", the number of fuseless switches is very small (only 2-3), the wire is a single-core wire or has become brittle. This means that the entire room's electrical circuits need to be replaced, and replacing wires usually requires opening walls and ceilings, which is a large-scale project.
• Water supply and drainage pipes: Turn off all water and observe whether the water meter rotates slightly (to determine whether the hidden pipe is leaking). Observe whether the water pipe is a galvanized iron pipe that is prone to rust. Pour a bucket of water to test the drainage speed. Extremely slow drainage means the pipeline is clogged or poorly designed.
• Comprehensive failure of the waterproof layer: Not only the bathroom, but also the exterior walls, window frames, balconies, and roofs of the entire house may have lost their waterproofing capabilities, leading to water seepage everywhere.
• Conclusion: If more than two of the three major systems of water, electricity and waterproofing need to be fully updated, then "partial repair" will become very embarrassing and uneconomical. Because if you update a part, the old part will soon have problems again, and it will be difficult to connect the work types. At this time, although the one-time expenditure of "comprehensive renovation" is high, it can solve all the core problems at once, which will save money and worry in the long run.

Assessment facet three: your "living needs", "budget" and "holding plan"

After the technical assessment, you must finally return to your personal conditions:

1. Intensity of living needs: Do you just need a temporary shelter, or do you want to build a long-term home that meets modern living habits (open kitchen, wet and dry bathrooms, sufficient sockets, smart home)? The higher the demand, the less partial repair can satisfy it.
2. Budget reality: In Taipei, the basic project of "comprehensive renovation" of old houses (including structural, water, electricity, waterproofing and cement work) is a pragmatic range of RMB 80,000 to RMB 150,000 per square meter, followed by woodwork, kitchenware, bathroom equipment, etc. Partial repairs may cost 30,000-60,000 yuan per square meter. You must understand the price difference between the two and evaluate your financial capabilities.
3. Hold time: How long do you plan to stay? If you expect to live there for more than 10 years, the daily cost is actually very low if you include a comprehensive renovation, and you can enjoy it most of the time. If it is just a transitional residence (within 5 years), then partial tidying up based on safety may be a more rational choice.

Decision tree: follow the process and find your answer

Based on the above, you can try to answer the following questions:

Q1: Does the house have serious structural safety problems?
Yes → Prioritize structure, hold off on lavish renovations. Tend to "make only necessary safety repairs."
No → Go to the next question.

Q2: Are any of the three major systems of water, electricity, and waterproofing completely worn out and need to be replaced?
Yes → It is strongly recommended to "completely renovate" once and for all.
No (only single or partial questions) → Go to the next question.

Q3: Do your living needs far exceed the current layout and functions? Do you have enough budget and plan to stay for a long time?
Yes → "Comprehensive renovation" can bring you the greatest return on quality of life.
No → "Partial repair" is a more cost-effective option.

No matter which path you choose in the end, remember: Safety is the bottom line, budget is reality, and life is the goal. Don’t ignore the real problems buried within the wall for the sake of superficial beauty. By honestly facing the situation of the house and your own needs, you can find the direction that best suits you at this crossroads.

The latest standards for catching leaks and regulatory responsibilities in Shuangbei collective housing (2025-2026 practice)

According to Article 10 of the "Apartment Building Management Regulations" of the Ministry of the Interior and the trend of civil water leakage judgments in Shuangbei District Court in recent years, most water leakage disputes in old collective housing focus on the identification and definition of "exclusive parts" and "common parts". The roof platform and the public pipes are jointly owned by all separate owners, and the repair costs should be shared by public funds or all residents in proportion to their shares according to law; if the water supply and drainage pipes inside the floor slabs on the upper and lower floors are damaged, the pipes will be borne exclusively by the users or shared by the upper and lower floors.

At the engineering and technical level, modern professional leak detection has fully introduced non-destructive scientific testing, including "FLIR high-resolution infrared thermal imaging camera" (locating temperature difference leakage paths), "high frequency moisture meter" (measuring the moisture content of deep structures) and "pipeline air pressure and water pressure pressure test" (determining whether hot and cold water pipes are leaking). During construction, do not directly apply elastic cement or oil-based paint on the wet cement layer to seal it. Otherwise, the thermal expansion of internal water vapor will quickly cause the coating to blister and peel off, resulting in more serious powdery wall cancer. The standard construction method must first completely eliminate the water source, wait until the moisture content of the cement structure drops below 8%, and then apply the negative pressure resistant silicic acid permeability crystallized waterproof layer.

Recommendations on independent certificate storage and compensation process for water leakage repair

1. Take photos and videos as evidence immediately: Use rulers to record the leakage range, frequency of water discharge, direction of water mark diffusion, and keep time stamps.
2. Written notification and coordination survey: Officially notify the neighbors through the management committee or a certified letter, and agree on a professional third-party leak detection and appraisal unit recognized by both parties to conduct an on-site survey.
3. The contract states the warranty terms: When signing the contract for the project, be sure to clearly specify the waterproofing warranty period (usually 1 year for partial repairs, and 2 to 5 years for the whole room or roof re-construction), and specify the water test acceptance criteria (such as a 48-hour water storage test in the bathroom shower area) to protect your own asset rights.