Buying a home is one of the biggest investments you'll ever make — but it's the hidden costs that catch most homeowners off guard. From failing foundations to termite damage, surprise repairs can drain tens of thousands of dollars if you're not prepared.

We recently shared our insights on this topic with Realtor.com, one of the nation's most trusted real estate platforms. In the article "The Silent Killers of Real Estate Wealth: 6 Surprise Home Repairs That Cost the Most — and How To Avoid Them", reporter Yaël Bizouati-Kennedy breaks down the six most expensive surprise repairs homeowners face — and we were honored to contribute our Hawaii-specific expertise.

Here's a deeper look at what every homeowner and buyer should know.

The 6 Most Expensive Surprise Home Repairs

1. Roofing Failures

A roof replacement can cost anywhere from $10,000 to $30,000+ depending on the size and materials. Most roofs last 20–30 years, but weather damage, poor ventilation, and deferred maintenance can shorten that lifespan significantly. Always ask for the roof age and inspection history before buying.

2. Foundation Problems

Foundation issues are among the most expensive repairs a homeowner can face — often $15,000 to $50,000 or more. Warning signs include cracked walls, sticking doors, uneven floors, and visible cracks in the foundation itself. A structural engineer's assessment is worth every penny if you suspect an issue.

3. HVAC System Replacement

A new HVAC system can run $7,000 to $15,000. These systems typically last 15–20 years, but without regular maintenance (filter changes, annual tune-ups), they can fail much sooner. Ask about the system age and maintenance records during your home inspection.

4. Sewer Line Damage

A broken or displaced sewer line from the house to the street is one of the most unpleasant and expensive surprises — often $5,000 to $25,000. Older homes are especially vulnerable. A sewer scope inspection (typically $200–$400) can catch this before closing.

5. Plumbing Failures

Aging pipes — especially galvanized steel or polybutylene — can corrode and fail without warning. A full re-pipe can cost $5,000 to $15,000+. In older homes, this is one of the most commonly overlooked issues.

6. Termite Damage

This is where our local expertise comes in. As we shared with Realtor.com:

"In Hawaii, we have both drywood and subterranean termites, and treatment for an active infestation in a single-wall construction home can run $5,000–$15,000, depending on severity. I tell every buyer: the $200 termite inspection is the cheapest insurance you'll ever buy."
— Kristy Nakamura, as quoted in Realtor.com

Termites are a reality of homeownership in Hawaii. The warm, humid climate makes every home a potential target — especially older single-wall construction homes. We always recommend a termite inspection as part of every transaction, whether you're buying or selling.

What Oahu Homeowners and Buyers Need To Know

Living in Hawaii comes with unique challenges that mainland buyers may not expect:

  • Moisture and mold: The tropical humidity accelerates mold growth, especially in poorly ventilated areas. Regular inspection of bathrooms, attics, and crawl spaces is essential.
  • Salt air corrosion: Homes near the coast are exposed to salt air that corrodes metal fixtures, roofing materials, and even electrical components faster than inland properties.
  • Single-wall vs. double-wall construction: Many older Hawaii homes are single-wall construction, which offers less protection against moisture, pests, and weather damage. Understanding what type of construction you're buying is critical.
  • Termite prevalence: As mentioned above, both drywood and subterranean termites are active year-round in Hawaii. Annual inspections and preventive treatment are standard practice here.
  • Leasehold considerations: Some properties on Oahu are leasehold rather than fee simple, which adds a layer of complexity to the investment. Understanding the lease terms, ground rent, and remaining lease duration is essential before purchasing.

How To Protect Yourself

  1. Never skip the home inspection. A $400–$600 inspection can save you $50,000+ in surprise repairs. Learn more about what to expect during the due diligence phase in Hawaii real estate.
  2. Get a termite inspection. In Hawaii, this is non-negotiable. The $200 cost is nothing compared to a $15,000 treatment.
  3. Request a sewer scope. Especially for homes built before 1980.
  4. Ask about the age of major systems — roof, HVAC, water heater, and plumbing. If they're nearing end of life, factor replacement costs into your offer.
  5. Set aside a maintenance reserve. We recommend budgeting 1–2% of your home's value annually for maintenance and repairs.
  6. Work with a local agent who knows what to look for. Every market has its quirks — in Hawaii, it's termites, moisture, and construction type. A knowledgeable agent will flag these issues before they become your problem.

Read the Full Article

We're grateful to Yaël Bizouati-Kennedy and Realtor.com for including our insights in this important piece. You can read the full article here:

👉 The Silent Killers of Real Estate Wealth: 6 Surprise Home Repairs That Cost the Most — and How To Avoid Them (Realtor.com)

Thinking About Buying or Selling on Oahu?

We're Kristy and Austin Nakamura from Your Oahu Home Team at eXp Realty. Whether you're a first-time buyer, a military family PCS'ing to the island, or a homeowner thinking about selling, we're here to help you navigate every step — including making sure surprise repairs don't derail your investment.

kristy@youroahuhome.com🌐 youroahuhome.com
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