Ground guarantee system

Characteristics of House Warranty

In the House Warranty’s land warranty system, the House Warranty, a third party, assesses the result of ground investigation conducted according to the Building Standards Act and offers appropriate foundation specifications, as well as guarantees restoration from uneven settlement.

Ground guarantee + Liquefaction guarantee

Ground guarantee + Liquefaction guarantee
Guarantee against damage due to liquefaction phenomenon is possible
  • Ground guarantee

    Warranty period : 20 years[Update possible]
    Guarantee limit : 50 million yen
    Deductible amount : 0 yen

  • Liquefaction guarantee

    Warranty period : 10 years[Update possible]
    Guarantee limit : 5 million yen
    Deductible amount : 0 yen

The warranty of House Warranty is a system that can contractorly undertake ground work in a third-party position in order to protect the owner's property.

Basic flow of ground guarantee system

  1. Research

    The risk of uneven settlement cannot be determined simply by numeric data obtained through ground investigation. The House Warranty entrusts an investigation from various aspects to an affiliate company, taking into consideration the numeric values and the locational conditions, surrounding environment and soil quality.

Balancing “low cost” and “high level of safety”

By completing a ground investigation at a high cost, you may be able to deeply explore the possibility of uneven settlement. However, such a cost is too large for an ordinary housing. Therefore, House Warranty employs a simplified and low cost ground investigation method.

Be advised that this is just a simplified ground investigation method and it is not possible to completely eliminate the possibility of ground accident. To cover the remaining uncertainty, we offer a guarantee.
Based on the long-accumulated expertise as an expert in ground guarantee as well as highly accurate analyses backed up by experiences with past cases, we will reduce the number of ground accidents as much as possible to zero.

  1. Analysis / proposal

    By comprehensively analyzing all investigation data, we will propose foundation specifications that are most appropriate for the building and the ground. Work to produce the foundation specifications according to the proposal servers as the precondition for ground guarantees.

“A third party” judges the necessity for improvement work

By separating the company that conducts the investigation and the company that completes the improvement work and thus analyzing and judging the investigation data from a third party’s point of view, we objectively determine the necessity in a grey zone where it is uncertain whether improvement work is really required. In this manner, the number of housings that can secure the safety without conducting improvement work will drastically increase.


If the risk of uneven settlement is recognized because of soft ground or similar factors as a result of analysis, we will conduct reinforcement work of the foundation or ground improvement work. Even in this case, we will offer an appropriate work so as to avoid excessive quality.

Various ground improvement methods are subject to warranty.

The ground improvement work method has also progressed.In addition to the conventional work method, House Warranty recommends the environment-friendly Eco method.


We provide solid ground survey, analysis and guarantee.

The ground is part of the house.
Let's make sure the ground is safe.

I am very worried about natural disasters such as earthquakes and heavy rain.
The seriousness of ground disasters has also been taken up in news and others.
It will become difficult to open and close the door if the house tilts.
House warranty is addressing every problem about the ground.In addition, we are doing activities to spread the importance of the ground.
We provide ground survey, analysis, and assurance of security so that everyone can live at home safely.