[Construction] ¥75.5tn Investment, Shrinking Workforce — Big-5 Market Share

Note: This article is a factual summary based on Obayashi Corporation’s published IR material (Investors’ Guide, June 2026 edition). It is not a recommendation to buy or sell any security. Figures are as of the publication of the source material. Investment decisions are your own responsibility.

This page steps back from Obayashi itself to look at the Japanese construction industry as a whole — how big the market is, how its workforce has changed, and how the leading contractors split it up. It is useful context for the rest of this guide: Obayashi’s own results (see Company Overview) sit inside these industry-wide numbers, and its own domestic building and domestic civil engineering segments compete directly with the contractors named below.

The construction-investment cycle: ¥83.9tn to ¥41.9tn to ¥75.5tn

Obayashi tracks Japan’s total construction investment — public and private, building and civil engineering combined — back to the mid-1980s. The market peaked at ¥83.9tn in FY1992, fell to ¥41.9tn by FY2010, and is forecast to reach ¥75.5tn in FY2025 — back close to its early-1990s level after a long recovery. The chart splits each year’s total into four categories: building construction (public and private) and civil engineering (public and private), alongside the workforce line described below.

Fiscal year	Construction investment	Note
FY1992	¥83.9tn	Peak
FY2010	¥41.9tn	Post-bubble trough
FY2025	¥75.5tn	Forecast

Obayashi attributes the current strength to the return of manufacturing bases to Japan, urban redevelopment, national resilience measures, and infrastructure renewal — the same themes that appear at the segment level in our domestic building and domestic civil engineering articles.

A workforce down about 30% since its peak

The number of workers in Japan’s construction industry has not kept pace with the market’s recovery. It peaked at 6.85 million in FY1997 and had fallen to 4.77 million by FY2024 — down approximately 30% from FY1997, per Obayashi’s own figures — while the remaining workforce has also aged considerably.

Metric	FY1997	FY2024
Number of construction workers	6.85 million	4.77 million
Aged 55 or older	24.1%	36.7%
Aged 29 or younger	22.0%	11.7%

The share of workers aged 29 or younger nearly halved, from 22.0% to 11.7%, while the 55-and-older share rose from 24.1% to 36.7%. In other words, more than a third of the industry’s remaining workers are now within a decade or so of typical retirement age, while the pipeline of new entrants has thinned considerably. This shrinking, aging workforce is the backdrop for Obayashi’s own recruitment, training, and automation initiatives, covered in our workforce and Robotics Construction® article. Obayashi compiles this data from construction-investment estimates published by MLIT — Japan’s Ministry of Land, Infrastructure, Transport and Tourism — and Labour Force Survey data from MIC, the Ministry of Internal Affairs and Communications.

Market share: the Top 23 general contractors

Obayashi also benchmarks itself against the wider industry using MLIT’s survey of orders received. On this basis, Japan’s 23 largest general contractors received orders worth ¥13.6tn in FY2024 — 16.8% of the total — while the remaining 83.2% (¥67.4tn) went to other contractors nationwide. This first comparison is measured on an orders-received basis; the two comparisons that follow switch to a net-sales basis, so the percentages are not directly interchangeable across the three tables in this section.

Group	Orders received (FY2024)	Share
Top 23 general contractors	¥13.6tn	16.8%
Other contractors	¥67.4tn	83.2%

Within that Top-23 group, net sales are concentrated at the very top. Obayashi’s data splits the group into three tiers: the five largest contractors (the ‘Top 5’) account for 55.6% of the Top-23 group’s net sales, the next ten (the ‘Upper-Mid Tier’) account for 33.9%, and the remaining eight (the ‘Mid-Tier’) account for 10.5%.

Tier	Share of Top-23 net sales
Top 5	55.6%
Upper-Mid Tier (next 10)	33.9%
Mid-Tier (8)	10.5%

So more than half of the combined net sales of Japan’s 23 largest contractors flow through just five companies — and Obayashi is one of them, as the next section shows.

The Big 5: where Obayashi ranks

Obayashi also publishes a direct net-sales comparison of the five largest Japanese general contractors — Obayashi, Taisei, Kajima, Shimizu, and Takenaka, the same five companies that make up the ‘Top 5’ tier above — using each company’s own non-consolidated financial results as of the end of March 2025. On this measure, Obayashi ranks first.

Company	FY2024 net sales (¥bn)	Share of Top-5 total
Obayashi Corporation	1,660.6	22.0%
Taisei Corporation	1,637.8	21.7%
Kajima Corporation	1,560.0	20.6%
Shimizu Corporation	1,501.5	19.8%
Takenaka Corporation	1,202.1	15.9%

The top four are tightly bunched between 19.8% and 22.0% of combined Top-5 sales, with Obayashi narrowly ahead of Taisei. Takenaka trails the other four at 15.9%. Unlike the Top-23 breakdown above, this comparison names each company individually, using each one’s own non-consolidated financial results as of the end of March 2025 — a common basis for comparing Japanese general contractors, since much of their work is booked at the parent-company level rather than through subsidiaries. These figures are not directly comparable to the consolidated group sales figures used elsewhere in this guide — see Company Overview for Obayashi’s ¥2,586.2bn consolidated net sales, a larger figure than the ¥1,660.6bn shown here because it adds overseas construction, real estate development, and other consolidated group businesses on top of domestic non-consolidated sales.

Together, these two pages describe an industry that employs far fewer people than it did thirty years ago but is still investing close to record sums, with sales concentrated at the top among five broadly similar-sized supermajors — of which Obayashi is narrowly the largest by this measure. For how Obayashi is responding to the labor side of that picture, see our workforce and Robotics Construction® article; for how the domestic construction segments themselves are performing against this industry backdrop, see domestic building and domestic civil engineering.

This article is part of our complete breakdown of the Obayashi Investors’ Guide 2026. See the hub article for the full series.

Note: This article is a factual summary based on Obayashi Corporation’s published IR material (Investors’ Guide, June 2026 edition). It is not a recommendation to buy or sell any security. Figures are as of the publication of the source material. Investment decisions are your own responsibility.