West Japan Civil Engineering

What West Japan Civil Engineering does

West Japan Civil Engineering (西日本土木株式会社, Nishinihon Doboku Co., Ltd.) is a privately held Japanese general construction and aggregates conglomerate founded in 1943 in Bungotakada City, Oita Prefecture, and incorporated in 1948. The company operates a dual-headquarters structure across Bungotakada and Oita City and serves the Kyushu region through three core divisions — civil engineering (roads, bridges, river improvement, slope stabilization, structural repair), building construction (public facilities, healthcare, schools, factories, retail, residential), and crushed stone production (9 plants across Oita, Kumamoto, and Miyazaki prefectures producing the highest aggregate output in West Japan).

The group's business model is project-based and centered on competitive public tendering with national and local government agencies, supplemented by direct enterprise sales for private building projects and direct sales to civil engineering contractors for aggregates. Revenue streams include one-time construction contracts (civil and building), volume-based recurring aggregate sales, asphalt and ready-mix concrete manufacturing, hot-dip galvanizing through group company Takita Denki Seisakusho, paid nursing care via Hakuyuso (白雲山荘), and minor hydroponic agriculture. Group sales were 10 billion JPY as of July 2022 with approximately 400 employees across core operations and 11+ subsidiaries.

The company's technical capabilities include certified ZEB Planner registration, allowing it to plan, design, and construct Net Zero Energy Buildings end-to-end — demonstrated by its own Bungotakada headquarters (completed March 2023, achieving 104% primary energy reduction including renewables). Distribution is purely direct field sales across Kyushu with no retail or e-commerce channels, and marketing leverages corporate website, Instagram, YouTube, LINE, and regional earned media. Customer mix is government-tilted (MLIT Kyushu, Oita Prefecture, municipalities) with named private clients across healthcare, education, automotive retail, and commercial sectors.

Name

West Japan Civil Engineering

Legal name

西斯本土木株式会社

Website

https://nnh.co.jp

Company type

Private

Founded year

1943

Operating status

Operating

Headcount range

101–250 employees

Short description

West Japan Civil Engineering (西日本土木株式会社) is a privately held Kyushu-based general construction and aggregates conglomerate founded in 1943, operating civil works, building construction, and West Japan's largest crushed stone production network (9 plants across 3 prefectures) for government and private-sector clients in Oita, Kumamoto, and Miyazaki.

Ownership category

akta.pro rank

Product category

Civil Engineering & Construction

NAICS

Highway, Street, and Bridge Construction (237310), Heavy and Civil Engineering Construction (237), Commercial and Institutional Building Construction (236220), Water and Sewer Line and Related Structures Construction (237110)

SIC

Heavy Construction Other Than Bldg Const - Contractors (1600), Mining & Quarrying Of Nonmetallic Minerals (No Fuels) (1400), Water, Sewer, Pipeline, Comm & Power Line Construction (1623), General Bldg Contractors - Nonresidential Bldgs (1540)

akta.pro primary industry

Construction Aggregates Mining & Processing (Sand, Gravel, Crushed Stone) (IMADAAAI)

akta.pro secondary industries

Roadside Structures & Ancillary Works (Noise Barriers, Lighting, Guardrails, Fencing) (IMAFAEAJ), Erosion & Sediment Control (Silt Fences, SWPPP Implementation) (IMAFAKAN), Storage & Conveyance Structures (Reservoirs, Tanks, Culverts, Tunnels) (IMAFAGAE), Rail Drainage, Earthworks & Right-of-Way Construction (IMAFAFAH)

Keywords

• Civil engineering construction
• Crushed stone aggregates
• Building construction services
• Asphalt mixture manufacturing
• Ready-mix concrete

Headquarters

HQ city

Oita

HQ country

Japan

HQ region

Asia

Offices11 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Supply Chain, Operations, Infrastructure, Technology or R&D, Marketing or Sales, Others

Revenue model

1. Civil Engineering Construction: Public works contracts including road construction, pavement, river improvement, slope stabilization, and structural repair. Revenue is project-based and earned upon contract award and milestone completion. Government contracts are a major revenue driver.
2. Building Construction: Construction of public facilities (schools, fire stations), healthcare/welfare facilities, commercial buildings, factories, condominiums, and private residences. Revenue is project-based.
3. Aggregates Sales: Production and sale of crushed stone and manufactured sand as raw materials for concrete and asphalt. Customers are civil engineering contractors. Revenue is volume-based and recurring as construction projects demand.
4. Ready-Mix Concrete and Asphalt Mixture: Manufacturing and sale of ready-mix concrete and asphalt mixture for construction projects.
5. Molten Zinc Plating: Metal processing services (molten zinc plating) provided through group company Takitadenki Seisausho, the only such processor in Oita Prefecture.
6. Nursing Care Services: Operation of Hakuyuso白云山庄, a paid nursing home for elderly residents, generating recurring service fees.

Pricing tiers

Go-to-market motion1 record

Distribution channels3 records

Marketing channels7 records

Core offering

West Japan Civil Engineering performs civil engineering construction (roads, bridges, rivers, harbors, and other public infrastructure), building construction (commercial, residential, and ZEB-certified net-zero energy buildings), and operates the largest crushed stone/aggregate production base in West Japan with nine plants across Oita, Kumamoto, and Miyazaki prefectures. The group also runs supporting businesses in hot-dip galvanizing, ready-mix concrete, asphalt mixture manufacturing, transportation, surveying and design, nursing care, and agriculture.

Product overview

West Japan Civil Engineering is a comprehensive construction company offering civil engineering, building construction, and crushed stone production services. The company operates a multi-business structure with core divisions for civil works (road, pavement, river, slope, and repair construction), building construction (public facilities, factories, offices, residences), and crushed stone production (9 plants across 3 prefectures producing aggregate for roads and concrete). Related services include hot-dip galvanizing, transportation, surveying, asphalt manufacturing, nursing care, and agriculture. The company also provides ZEB (Net Zero Energy Building) planning and construction services as a registered ZEB Planner. With a dual-headquarters system in Bungotakada City and Oita City, the company serves the Kyushu region through 9 group companies.

Differentiator

Problem solved

Functional benefit

Quantifiable outcome

• 104% primary energy reduction (ZEB certified) at Bungotakada headquarters building
• +2 more outcomes

Named customers9 records

Segments5 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Partnerships

Seven partnerships are on record, tiered core.

• 田北電機製作所 (Takitadenki Seisausho)coreTechnology or Integration · 1 January 2023Takitadenki Seisausho is a group company specializing in molten zinc plating — the only such processor in Oita Prefecture. Provides metal corrosion protection services for steel structures used in parking lots, arcades, and industrial applications. Enables integrated service offering for construction projects requiring metal finishing.
• クボタ不動産建設 (Kubota Real Estate Construction)coreStrategic or Co-development Partner · 1 January 2023Real estate trading, property management, construction, building maintenance, and renovation services. Became a group company in January 2023 alongside Kubota Development, Kubota Reform, and Kubota Maintenance.
• 九州アスコン (Kyushu Ascon)coreTechnology or Integration · 1 January 2008Asphalt mixture manufacturing and sales company with industrial waste intermediate processing. Provides asphalt for road construction projects in the Oita region.
• 朝日興産 (Asahikousan)coreTechnology or Integration · 1 January 2006Crushed stone manufacturing and sales company, and industrial waste intermediate processing. Became a group company in 2006. Operates a sandstone quarry in Oita city, producing aggregate for concrete and asphalt.
• クマダ商事 白雲山荘 (Kumada Shoji / Hakuyuso)coreOthers · 1 January 2005Operator of Hakuyuso白云山庄, a paid nursing home for elderly residents in Beppu city. Represents the company's entry into the senior care and wellness sector.
• 九豊コンサルタント (Kyuto Consultants)coreStrategic or Co-development Partner · 1 January 2001Surveying and design consulting company providing measurement, design, and engineering survey services that support civil engineering project planning and execution.
• （有）豊栄運輸 (Toyoei Transport)coreOthers · 1 January 1993General freight trucking company providing logistics and transportation services for construction materials and aggregate products. Located at the same address as the Usa branch.

Scale indicators6 records

Recent moves11 records

Expansion highlights5 records

Direct peers

• Nippo Corporation: Nippo Corporation (日本道路) is a Japanese road paving and civil engineering specialist with asphalt mixture production. Highly comparable to West Japan Civil Engineering's road construction, pavement, and asphalt manufacturing operations, though larger and national in scope.
• Nishimatsu Construction: Nishimatsu Construction (西松建設) is a major Japanese general contractor with a strong civil engineering and building construction portfolio. Comparable to West Japan Civil Engineering in core civil/building offerings and government contract exposure, though significantly larger in scale and national in footprint.

Broad incumbents

• Maeda Corporation: Maeda Corporation (前田建設工業) is a Japanese general contractor with civil engineering, building, and infrastructure operations. Comparable to West Japan Civil Engineering in core construction offerings and public works execution, though much larger and more diversified geographically.
• Tokyu Construction: Tokyu Construction (東急建設) is a Japanese general contractor with civil engineering and building construction operations. Comparable to West Japan Civil Engineering in core services and government/commercial project exposure, but larger scale and broader geographic reach.
• Hazama Ando Corporation: Hazama Ando (安藤ハザマ) is a major Japanese general contractor covering civil engineering, building construction, and infrastructure. Overlaps with West Japan Civil Engineering on civil works, building construction, and government project execution, though operates at much larger scale nationally.
• Toda Corporation: Toda Corporation (戸田建設) is a long-established Japanese general contractor engaged in civil engineering, building construction, and real estate development. Comparable to West Japan Civil Engineering across civil and building divisions, but operates nationally and at substantially larger scale.
• Sumitomo Mitsui Construction: Sumitomo Mitsui Construction (三井住友建設) is a Japanese general contractor with civil engineering, building, and prefab operations. Comparable to West Japan Civil Engineering in civil and building work, particularly bridge and infrastructure construction; operates at much larger national scale.

Emerging players

• Taiheiyo Cement: Taiheiyo Cement (太平洋セメント) is Japan's largest cement manufacturer with significant aggregate (crushed stone/sand) production operations. Comparable to West Japan Civil Engineering's aggregates division and provides relevant benchmarking for aggregate economics and supply dynamics in Japan.

Regional players

• Fudo Tetra Corporation: Fudo Tetra Corporation (不動テトラ) is a Japanese specialty civil engineering and construction company involved in foundation, slope stabilization, and ground improvement work. Comparable to West Japan Civil Engineering's civil engineering, slope stabilization, and aggregate-related operations.
• Kyudenko: Kyudenko (九電工) is a major Kyushu-based infrastructure company specializing in electrical and mechanical engineering construction. Comparable to West Japan Civil Engineering as a Kyushu-headquartered infrastructure contractor with deep regional government relationships, though focuses on electrical systems.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat5 records

Key risks6 records

Key highlights6 records

Customer concentration

• YouTubeyoutube.com/@西斯本土木株式会-z2o
• Instagraminstagram.com/nisinihon_doboku

Compliance7 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Subsidiaries11 records

Funding overview

Funding rounds1 record

Investors2 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about West Japan Civil Engineering