🚽 Can You Add a Toilet Where There Wasn’t One? Plumbing Tips for Old Homes in Japan

One of the biggest surprises when buying an akiya (abandoned home) in Japan is discovering that the house may not have a modern toilet—or sometimes, no indoor toilet at all. Instead, you might find:

• A pit latrine (汲み取り式便所 / kumitori-shiki benjo)
• A basic squat toilet with minimal plumbing
• Or, in some cases, no bathroom space whatsoever

So, the question many buyers ask is:
Can you add a toilet to a home that never had one?
The answer: Yes—but it depends on the plumbing, sewage, and layout.

This guide covers everything you need to know about installing a modern toilet in an old Japanese home.

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💧 Step 1: Check the Home’s Existing Water & Wastewater Setup

Before you decide where to put a new toilet, you need to know what kind of system your home is connected to:

1. City Sewer System (下水道 / gesuidō)
   • Best case scenario.
   • You can connect directly into the municipal sewer line.
   • Requires permits and possibly excavation if the line doesn’t already run to your property.
2. Septic Tank (浄化槽 / jōkasō)
   • Many rural homes rely on septic systems.
   • If the tank is too small, you may need an upgrade to handle toilet waste.
3. No Connection (Old Kumitori System or Nothing)
   • You’ll need to install a new septic tank before adding a flush toilet.
   • This can be one of the most expensive hidden costs in akiya renovation.

🏠 Step 2: Decide on the Toilet Type

Japan has a range of toilet options, from simple to ultra high-tech. When adding a new one, consider your budget and plumbing capacity:

• Western-Style Flush Toilet
  • Standard option for most renovations.
  • Requires full plumbing setup.
• Eco-Friendly Composting Toilet
  • Great for off-grid or ultra-rural homes.
  • Doesn’t require sewer or septic hookup.
  • Still unusual in Japan, but becoming more accepted.
• Tankless Bidet Toilet (ウォシュレット)
  • The luxury option.
  • Needs steady water pressure and electrical outlet nearby.

🔧 Step 3: Plumbing Considerations

Adding a toilet where none existed means planning carefully:

• Water Supply Line
  • A new pipe will need to be routed to the toilet location.
  • Old homes may need pipe replacements if water pressure is too low.
• Drainage Pipe
  • Requires slope and access to septic/sewer.
  • In older homes without crawlspace access, floor excavation may be necessary.
• Ventilation
  • Toilets require proper venting to prevent odor buildup.
  • Many old akiya bathrooms weren’t designed with this in mind.
• Electricity (for Washlets)
  • If you want heated seats or bidet features, an outlet must be installed safely near the toilet.

⚖️ Legal & Permit Requirements

In Japan, plumbing and septic work must be done by licensed professionals.
DIY installation is not allowed for:

• Sewer connections
• Septic tanks
• Major drainage systems

Your contractor will file applications with the local government, and in many areas, inspection is required before use.

🌱 Subsidies & Support

Many rural towns in Japan offer toilet and septic installation subsidies as part of revitalization efforts. These can cover 20–70% of costs depending on the region.
Old Houses Japan helps clients research and apply for these programs.

🧭 Final Thoughts

Yes—you can absolutely add a toilet to a Japanese home that never had one. But it’s not as simple as dropping in a new unit. You’ll need to carefully plan:

• Water and sewage connections
• Structural adjustments
• Budget for septic upgrades

With the right contractor and (hopefully) local subsidies, you can turn even the most basic akiya into a comfortable modern home.

📩 Want help planning your akiya renovation? Contact Old Houses Japan »