Document redevelopment cash-flow assumptions

When you evaluate a Japanese property for 再開発 (redevelopment) or 建替え (rebuilding), the cash-flow model is where most errors enter. A single wrong input, an assumed lease expiry, a misread zoning district, a guessed finance rate, can change the residual land value by millions of yen. The remedy is not a better spreadsheet; it is a documented assumption set that any specialist can review. This page gives you the method, the checklist, and the decision rule.

Every figure in a redevelopment cash-flow model has a source, a date, a method, and a sensitivity. If you cannot state those four things for an input, you have an assumption, not a fact. The method below lets you document each assumption so a specialist, appraiser, lawyer, 土地家屋調査士, 司法書士, or tax accountant, can review it without redoing your research. It does not give legal advice or a compensation formula. Japanese property law is date-sensitive; verify every figure with the current official text before relying on it.

Why separate the inputs?

Redevelopment cash-flow models fail when one blended “soft cost” or “construction contingency” line hides the assumptions inside it. A single wrong interest rate, a delayed permit, or an unrecorded lease can change the residual land value by more than the project margin. Separating land, construction, finance, tax, timing, revenue, and contingency inputs lets each assumption be checked against a named source, and lets a specialist review one line without unpicking the whole model.

Japanese property records are fragmented. The land register (登記簿) is held by the local Legal Affairs Bureau (法務局); the cadastral map (地図) is a separate record and may not match the register; building approval files sit with the local government planning department; and tax assessments are in the fixed-asset tax record. There is no single national portal for private use. A documented cash-flow model must therefore record the source of each input and the date it was read.

The document set you need before modelling

Collect these records before entering any number into a spreadsheet. Each record answers one question and has one authoritative custodian.

Record	Japanese term	Authoritative source	What it answers
Land register	登記簿	Legal Affairs Bureau (法務局)	Ownership, mortgages, easements, leasehold interests
Cadastral map	地図	Legal Affairs Bureau (法務局)	Parcel boundaries, survey accuracy
Urban planning map	都市計画図	Local government planning department	Zoning, road plans, public reservations
Building confirmation application	建築確認申請	Local government building department	Approved plans, compliance history
Fixed asset tax register	固定資産税台帳	Municipal tax office	Assessed value and building details
Koseki	戸籍	Local municipal office	Inheritance chains and heirs

The land register (登記簿) and cadastral map (地図) are separate documents. The register records ownership and encumbrances; the map records boundaries. A boundary discrepancy between the two can take months to resolve and may require a licensed land and building surveyor (土地家屋調査士) to correct.

Building and planning records

A building confirmation application (建築確認申請) is filed with the local government before construction; it contains structural plans and confirms compliance with the Building Standards Act (建築基準法). The Urban Redevelopment Act (都市再開発法) provides the legal framework for coordinated projects, including tenant relocation procedures. Local planning departments issue zoning certificates and planning certificates that confirm the applicable district and land-use restrictions.

The fixed-asset tax register (固定資産税台帳) is a municipal record of assessed value; it is not a market valuation and typically understates market price. The Land and Building Leases Act (借地借家法) governs lease renewal rights and eviction rules. The urban planning map (都市計画図) shows zoning, road reservations, and public facility plans that can affect redevelopment feasibility.

The National Land Numerical Information (国土数値情報) dataset provides GIS layers for land-use and zoning, but it is a secondary dataset: confirm against the municipal planning department’s official zoning certificate (都市計画証明書) before relying on it. The official land register (登記簿) is maintained by the Legal Affairs Bureau (法務局) and is divided into the parcel register, building register, and rights register; ownership, mortgages, and easements are recorded separately. A registered lease (地上権) may be recorded in the rights section, but an unregistered lease can still bind a purchaser under the Land and Building Leases Act, so the land register alone is not sufficient evidence of tenancy.

Property attributes to verify

Parcel area (地積) is the registered area of the land parcel; the actual surveyed area may differ, so a boundary survey by a land and building surveyor is required before design work. Building coverage ratio (建蔽率) sets the maximum percentage of the site that may be covered by building footprint; the ratio is set by zoning and may be reduced by road-width limits under the Building Standards Act. Floor-area ratio (容積率) defines maximum total floor area divided by site area; the ratio is a cap, not a target, and is reduced when the site fronts a narrow road.

Zoning category (用途地域) is a district-level use restriction that determines whether residential, commercial, industrial, or mixed uses are permitted. Road frontage width measures the public road the site abuts; sites not fronting a public road wider than 2 m may be considered 接道なし (no road access) and may not be buildable. Setback requirement is the distance from the site boundary to the building face, required by the Building Standards Act and often by local urban planning ordinances.

Seismic rating is a structural capacity indicator; buildings designed before the 1981 Building Standards Act revision may need seismic diagnosis (耐震診断) before redevelopment financing. Lease protection refers to rights under the Land and Building Leases Act (借地借家法); a registered lease term does not necessarily reflect the tenant’s statutory renewal right. Eviction notice validity requires a written “justified reason” (正当な事由) under the Act and, in practice, often involves negotiation of moving costs and temporary housing.

Taxes, fees and professionals

Registration fees are scaled by the fixed-asset tax value, not the sale price; the fee schedule is set by the Registration and Cadastral Fees Act. Key professionals include: 司法書士 (judicial scrivener) who handles registration; 土地家屋調査士 (land and building surveyor) who handles boundary and survey work; and 不動産鑑定士 (real-estate appraiser) who issues formal valuations.

Acquisition tax is a one-time tax on the assessed value of acquired land or buildings; the fixed-asset tax assessment is the base, not the market price. Fixed asset tax is an annual municipal tax based on the registered assessed value; the assessed value is usually lower than the market price. Property tax and city planning tax are annual taxes levied by the municipality; the amount depends on the fixed-asset tax register.

Building confirmation is a formal approval of construction plans by the local government, required before starting new construction or major renovation. Completion inspection is a post-construction inspection verifying that the building matches the approved plans; the certificate is issued by the local government or a designated inspection body. Ownership transfer registration records a change in owner in the land register; it is required for legal ownership transfer, not merely recommended. Inheritance registration transfers title after death; it is required before the deceased owner can be removed from the land register.

A cadastral survey provides official boundary measurement, needed when boundaries are unclear or when subdividing or merging parcels. Fixed asset tax assessment is the municipal valuation for annual property tax; this is not a market valuation and is typically 50-70% of market price (MLIT, 2023).

Procedure: the research sequence

Pull the official land register (登記簿) from the Legal Affairs Bureau covering the parcel. Check the ownership section, mortgage and lien section, and any restrictions on disposal.
Pull the cadastral map (地図) for the same parcel and compare it with the land register. Cadastral maps may not be fully digitised or integrated with the register, so discrepancies are common.
Request the fixed-asset tax register from the municipal tax office, and compare assessed value against the registered land price. The assessed value is usually 50-70% of market price and is not a reliable market proxy.
Obtain the building confirmation application (建築確認申請) from the municipal construction or planning department; this contains the original plans and shows whether the current structure matches the approved design.
Check the urban planning map (都市計画図) to identify zoning, road reservations, and redevelopment promotion areas that affect buildable area.
Review the koseki (戸籍) for inheritance chains when the registered owner is deceased; the land register alone will not show the current heir.
Cross-reference the fixed asset tax register (固定資産税台帳) against the land register to detect parcels that are taxed separately or omitted from the official register.
For redevelopment projects, obtain the relevant redevelopment plan (再開発計画) from the municipal planning department and check whether the property falls inside a designated redevelopment promotion area.
Verify building confirmation application records (建築確認申請) for structural compliance, especially for buildings constructed before the 1981 seismic code revision.
Use the National Land Numerical Information (国土数値情報) for GIS-based overlay analysis of zoning, road plans, and hazard areas.
Cross-check the cadastral map (地図) against the land register (登記簿) to identify boundary discrepancies, unregistered parcels, and co-ownership shares.
Search the koseki (戸籍) to trace inheritance chains when the land register lists a deceased owner or an unresolved succession.