If the inherited house fronts a co-owned private road, why is excavation consent needed before selling?

The key point: When an inherited house fronts a private road co-owned by several people, bringing in water/gas or rebuilding—work that digs up the road—in principle needs the other co-owners' involvement. The Civil Code (Act No. 89 of 1896) provides that a change that markedly alters a shared thing needs the consent of all co-owners (art. 251(1)); management not involving a marked change of form or function is decided by a majority of the value of co-ownership shares (art. 252(1)); and acts of preservation may be done by each co-owner alone (art. 252(5)). The Ministry of Justice "Research report on owner consent needed for works on a privately owned road held by several persons—Guideline for responding to private roads with unknown owners (2nd ed., June 2022)" organises road repaving as an act of preservation and much work such as lifeline connection as an act of management (majority), and it is usual practice to secure this consent (excavation consent) before selling. Where a co-owner's whereabouts are unknown, the 2021 reform (in force 1 April 2023) provides for acquisition of the unknown co-owner's share (Civil Code art. 262-2), transfer of the share (art. 262-3), and court decisions to decide management/change excluding that person (art. 251(2), art. 252(2)). Brokerage of the sale and connection coordination is ours (a real-estate transaction business); representation in negotiation and mediation is a lawyer's, confirming the rights relations of the consent document and registration a judicial scrivener's, and capital-gains tax a tax accountant's, each an independent business contracted with separately (no referral fees are exchanged).

For heirs whose inherited family home or land fronts a co-owned private road and who want to secure excavation consent from the other co-owners before selling, this article organises why consent is needed and which systems move things forward, in the order of the statutory text and the Ministry of Justice guideline. This is general information; the final judgment on which act type a particular work is, and which procedure to use when consent cannot be obtained, rests with lawyers, judicial scriveners and the court.

Yotsuba Real Estate Co., Ltd. (四葉不動産株式会社), based in Bunkyo, Tokyo, provides surveys of inherited real estate and brokerage of sale and connection coordination. For a property fronting a co-owned private road, you can consult us from what can be confirmed before contracting.

Why does co-owned private-road excavation consent become necessary before selling?

If the frontage road is a "co-owned private road," that road is a shared thing of several people. Bringing in a new water/gas pipe, replacing an old one, or digging up the road for a rebuild is an act of digging land in which others also hold shares. The Civil Code divides how a shared thing is handled by the nature of the act.

Type of act	Involvement needed	Basis
Act of preservation (maintaining the status quo; minor repaving, etc.)	Each co-owner may do it alone	Civil Code art. 252(5)
Act of management (including minor change)	Decided by a majority of the value of co-ownership shares	Civil Code art. 252(1)
Act of change (involving a marked change of form/function)	Consent of all co-owners	Civil Code art. 251(1)

Further, where a management decision would have a "special effect" on one co-owner, that co-owner's consent is needed (art. 252(3)). The problem is that unless all-consent or a majority is securely in hand at the time of work, the contractor hesitates to start and the buyer cannot obtain financing. So it is widely practised to secure consent (excavation consent) from the relevant co-owners before selling. This both meets the statutory consent requirement and is a practical measure to avoid future trouble and let the buyer start work directly.

How does the Ministry of Justice private-road guideline organise consent for excavation?

The Ministry of Justice "study group on preservation and management of co-owned private roads" has published a report organising, case by case, how much consent each work needs. The 2nd edition of June 2022 is the latest, reflecting the 2021 Civil Code reform (Act No. 24 of 2021); the 1st edition was January 2018.

The guideline organises work roughly as follows by its nature (an outline; the conclusion changes with individual circumstances).

Example of work	Act type (the guideline's organisation)
Repairing/repaving the private road	Act of preservation (each co-owner may do it alone)
Newly laying a private water-supply pipe for one's own use	May, in some cases, be done alone as use according to one's share
Newly laying a public sewer pipe	Act of management (decided by a majority of the value of shares)
Setting a right of use for a lifeline operator	Usually an act of management (majority)
Work with a special effect on some co-owners, such as causing a long water stoppage	Individual judgment (the consent of the co-owner with the special effect is needed)

The 2021 reform widened the scope of "management" so that a "minor change" not involving a marked change of form/function can also be decided by a majority. Excavation to bring in a lifeline often does not markedly change the road's form/function and is often organised as within management (majority). But which work falls into which type varies with the pipe's route, diameter and the scale of excavation, and whether there is a special effect is an individual judgment per case. Confirm the application of the types and the scope of consent with a lawyer/judicial scrivener.

What can you do when a co-owner's whereabouts are unknown?

On co-owned private roads, it is not rare that, as inheritances pile up and shares fragment, there is a co-owner one cannot reach (a co-owner of unknown whereabouts). The 2021 reform set up systems to move forward with the court's involvement in such cases (in force 1 April 2023).

Trouble	System available	Basis
Want to make a change excluding the unknown co-owner	By court decision, a change may be made with the consent of co-owners other than the unknown one	Civil Code art. 251(2)
Want to decide management excluding the unknown co-owner	By court decision, management matters may be decided by a majority of shares of co-owners other than the unknown one	Civil Code art. 252(2)
Want to acquire the unknown co-owner's share itself	By court decision, the other co-owners may acquire that share	Civil Code art. 262-2
Want to sell to a third party including the unknown co-owner's share	By court decision, a power to transfer the share is granted	Civil Code art. 262-3

Each of these requires a petition to the court, premised on investigating that the whereabouts are unknown (resident record, family register, real-estate registration, etc.) and on a deposit. Which procedure to choose and how to frame the petition is the field of a lawyer/judicial scrivener. We read the current state of co-owners and shares from the registry and the official map, and organise the premises of the process—including how easy each is to reach—to hand to you.

What do you have written in the consent document, and how is it passed to the buyer?

Excavation consent means little orally; a written document is the premise. So that the buyer, the financial institution and the contractor can start work with confidence, it is usual to include the following in the consent document (drafting the text and confirming the rights relations is a judicial scrivener's/lawyer's field).

• Permission to install/excavate water, drainage and gas pipes, and the rough range of their position/route
• Permission for future re-excavation for inspection, repair and replacement
• The method of restoring the road after work and who bears the cost
• That this consent also extends to the transferee (buyer) of the land and their successors (a succession clause)

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The succession clause is especially important: even if you, the heir, obtain consent, unless it passes to the buyer the buyer will have to obtain consent again, so it is essential if a sale is in view. Within the sale brokerage, we check the presence/scope/succession of such consent as a point of property survey, and connect you to a judicial scrivener/lawyer where it is lacking. Drafting the consent document itself, and negotiation/litigation where consent cannot be obtained, are not our work.

Who do you consult for negotiation, registration and tax?

Selling a co-owned private road spans separate professional fields: the survey of the property and consent, negotiation, registration and tax. What we handle is the survey of the property and the brokerage of sale and connection coordination; everything else we connect to each professional, each an independent business contracted with separately.

Trouble	Who to ask
Current-state survey of the co-owned private road; brokerage of sale and connection coordination	Us (a real-estate transaction business)
Consent not obtained and negotiation turns into a dispute; mediation/litigation; petitions regarding an unknown co-owner	Lawyer
Transfer registration of the co-ownership share; confirming the rights relations of the consent document	Judicial scrivener
Capital-gains tax on the sale	Tax accountant

These are each independent businesses, contracted with separately. We neither receive nor pay referral or introduction fees. Whether consent can be obtained, and which court procedure to use, is ultimately judged by a lawyer/judicial scrivener and the court. Looking at the property, we take consultations from separating the issues—the need for consent, its scope and succession, whether there is an unknown co-owner—and arranging who to consult on each. For how to proceed with inherited real estate, see also the consultation desk for inherited real estate (Japanese).

Consult Yotsuba Real Estate about inherited real estate fronting a co-owned private road—initial consultation is free

In your message, write "co-owned private-road excavation consent" and include the rough number of co-owners of the road, whether there is a co-owner you cannot reach, and whether it is a water/gas connection or a rebuild. Without presuming whether consent can be obtained, we begin with the current-state survey and with arranging which parts to refer to professionals for negotiation, registration and tax.

Frequently asked questions

Q. Does simply inheriting require consent from the landlord or other co-owners?
A. Inheriting a share of a co-owned private road itself does not require the other co-owners' consent (inheritance transfers rights by operation of law). Consent becomes an issue when you dig up the road for a water/gas connection or a rebuild, and when you secure consent for the buyer in preparation for a sale. Depending on the nature of the work, it falls under an act of preservation (alone), management (majority) or change (all consent) (Civil Code arts. 251, 252). Confirm the application with a lawyer/judicial scrivener.

Q. Does excavation need everyone's consent, or is a majority enough?
A. It depends on the nature of the work. The Ministry of Justice guideline (2nd ed.) organises work such as lifeline connection that does not markedly change the road's form/function as an act of management (a majority of the value of shares), while work involving a marked change needs the consent of all (Civil Code art. 251(1)). Also, where there is a special effect on some co-owners (such as a long water stoppage), that co-owner's consent is needed (art. 252(3)). Since the conclusion changes with the pipe's route and scale, confirm the individual application with a professional.

Q. If there is a co-owner I cannot reach, does that mean I cannot sell?
A. Not necessarily. The 2021 Civil Code reform (in force 1 April 2023) set up acquisition of an unknown co-owner's share (art. 262-2) and transfer of the share (art. 262-3), and court decisions to decide management/change excluding that person (art. 251(2), art. 252(2)). Each is premised on a petition to the court and an investigation of the unknown whereabouts. Which procedure to choose is the field of a lawyer/judicial scrivener; we help within the range of brokerage and current-state survey.

Q. Is the consent document passed to the buyer?
A. It is not passed automatically, so it is usual to include a succession clause in the consent document stating that "it also takes effect for the transferee (buyer) and their successors." Without it, the buyer has to obtain consent from the co-owners again, which can stall the sale. Drafting the consent document and confirming the rights relations is a judicial scrivener's/lawyer's field; within the sale brokerage we check the presence/scope/succession of consent and connect you to a professional where it is lacking.

Sources

The following public materials are starting points. Laws are amended, so check the current text, paragraph, item, enforcement date and latest amendment on e-Gov Law Search. The final judgment on the application of the act type, the scope of consent, and procedures regarding an unknown co-owner rests with lawyers, judicial scriveners and the court. All were consulted on 28 October 2026. They do not guarantee the result of any particular work or sale. The sources below are in Japanese.

• e-Gov Law Search: Civil Code (Act No. 89 of 1896; arts. 249–264 = co-ownership [art. 251 = change of the shared thing {(1) a change involving a marked alteration needs the consent of all; (2) a court decision that a change may be made with the consent of co-owners other than the unknown one}, art. 252 = management of the shared thing {(1) a majority of the value of shares, (2) a court decision excluding the unknown co-owner, etc., (3) consent where there is a special effect on some co-owners, (5) acts of preservation may be done by each co-owner alone}, art. 262-2 = acquisition of an unknown co-owner's share, art. 262-3 = transfer of an unknown co-owner's share]; arts. 262-2, 262-3 and art. 251(2), 252(2) were newly added by Act No. 24 of 2021, in force 1 April 2023)
• Ministry of Justice: Research report on owner consent needed for works on a privately owned road held by several persons—Guideline for responding to private roads with unknown owners (2nd ed.) (June 2022; organises work on co-owned private roads into preservation/management/change—repaving as preservation, much work such as lifeline connection as management (majority), and individual judgment where there is a special effect. 1st edition January 2018. Consulted 28 October 2026; individual application is case-by-case)
• e-Gov Law Search: Waterworks Act (Act No. 177 of 1957; provisions on water-supply equipment) / Sewerage Act (Act No. 79 of 1958; art. 10 = obligation to install drainage facilities, etc.; the laws underlying connection and drainage-facility installation)

This article provides general information and does not guarantee which act type a particular work is, whether consent can be obtained, or which court procedure is available. The application of act types and negotiation/mediation/litigation are judged by a lawyer; transfer registration of shares and confirming the rights relations of the consent document by a judicial scrivener; capital-gains tax by a tax accountant; and petitions regarding an unknown co-owner by the court.

Joji Uramatsu (浦松 丈二), Representative Director and licensed real estate transaction specialist, Yotsuba Real Estate Co., Ltd. (四葉不動産株式会社). We provide surveys of inherited real estate and brokerage of sale and connection coordination. Author profile

Updated: 28 October 2026