Silicon Almanac.All explainers
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Edition 1 27 September 2026

How fast can you build a fab?

Terafab is the largest chip factory anyone has announced. The fastest fab builders in the world never announce anything. This is both of them side by side, with the numbers each one has published.

This page is a dated snapshot of a story that is still moving. It shows what was on the public record on 27 September 2026. We plan to update it every quarter, after Tesla reports its results, and each edition will say what changed.

100m+ sq ftTerafab's stated size: more than 100 million
1mwafers a month, its stated goal
22 monthsfrom groundbreaking to opening in Kumamoto

Scene: Terafab's stated floor area as a square, drawn at 100 million square feet, with Tesla's Giga Texas inside it. Every figure is named with its publisher where it is used, and all sources are listed at the end.

01 What has been said

The claims, in order.

Elon Musk announced Terafab in Austin on 21 March 2026: $25 billion, 2 nm chips, 100,000 wafer starts a month to begin with, and one million a month in the long run. Intel joined on 23 April and Terafab will use Intel's 14A process. In May a Texas filing put the prototype phases at up to $119 billion. In August, Tesla and SpaceX named the site: Grimes County, Texas, with a first phase reported at $16.8 billion.

SpaceX's own registration statement says: "Any specific projects undertaken pursuant to this framework will be subject to separate negotiations and agreements (including any development timelines, milestones and capital expenditures) and have not yet been determined."

Electrek (March and August 2026); Intel Q1 2026 earnings release; CNBC (6 May 2026) on the Texas filing; SpaceX Form S-1. The $16.8 billion was reported in the press. The filing says capital expenditure has not been determined, so the scene draws that bar grey. The $119 billion is an upper bound and is drawn transparent.

02 Scale

More than 100 million square feet.

At 100 million, that is 9.29 million square metres. Each building below is drawn as a square with its floor area, all starting from the same corner. The amber outline is Terafab.

Floor area0
At 100 million, Terafab is0

Terafab's size was stated by SpaceX and Elon Musk, as reported by Electrek (6 August 2026) and Fortune (10 August 2026). No SpaceX filing was found to contain the figure: we searched the Form S-1, both amendments and the final prospectus on 27 September 2026. Floor areas from Wikipedia's list of largest buildings, read 27 September 2026. Fortune (10 August 2026) makes the same comparison with the Chengdu building. The ratios are our arithmetic, at 100 million. We do not know if the stated size is floor area or site area, and the two are not the same thing. So no fab is drawn here: fab sites are usually published in acres, which is site area.

03 Output

A million wafers a month.

A fab's size is counted in wafer starts a month. Each stack is drawn to its number: amber is Terafab, blue is what exists or is forecast. Pick one to compare it with the goal.

Wafers a month0
Terafab's goal is0

TSMC GIGAFAB page (read 27 September 2026, no date on the page); TSMC 2025 Annual Report; SEMI (25 June 2025). The comparisons are our arithmetic. The bases differ: SEMI counts 300 mm wafers, TSMC counts 12-inch equivalents, and Terafab has not said which wafers it counts. A forecast is one vintage of a number that gets revised.

04 Time

The clock starts at groundbreaking.

Exyte, which designs and builds fabs, puts the average build at 19 months in Taiwan and 38 in the United States. Taiwan builds around the clock and gets permits in 6 to 13 months. In the US, permits and design take 14 to 20 months and building is done in daytime shifts.

TSMC's Kumamoto fab, built by Kajima, started construction in April 2022 and opened on 24 February 2024. In 2018 TSMC planned to move tools into Fab 18 about a year after breaking ground. Its first Arizona fab was planned for 2024 and reached volume production in early 2025.

Clock0

Exyte, presented at SEMI's Industry Strategy Symposium and reported by Semiconductor Digest and Tom's Hardware (February 2025); TSMC press releases (26 January 2018, 24 February 2024); Wikipedia on TSMC Arizona, citing TrendForce. The milestones are not all the same: an average build, an opening and a planned tool move-in. Read them as orders of magnitude, not as a race result.

05 The builders

The fastest builders publish nothing about speed.

Taiwan's fab builders are cleanroom and systems contractors such as L&K Engineering and United Integrated Services. They build for TSMC at home, and increasingly in Arizona, Japan and Europe. The press reports them by their order books. We found no build times published by any of them.

That is the contrast in this story. The record holders for speed publish their backlog, and the newcomer publishes its ambition.

Taipei Times (23 June 2025): order backlogs as reported by the companies. NT$ figures are not converted. "We found no build times" describes our own search, dated 27 September 2026, and says nothing about what the companies know.

06 Lithography

The machine on the critical path.

A leading-edge fab cannot start without EUV scanners, and one company makes them. ASML recognised 48 EUV systems in its 2025 revenue. In July 2026 it said its 2026 capacity for low-NA EUV is "around 65", that it plans to add 30% for 2027, and that it is investigating another 30% for 2028.

EUV systems0
One box isone machine

ASML Q4 2025 investor presentation (28 January 2026); ASML Q2 2026 results (15 July 2026), CEO statement. 85 and 110 are our arithmetic on ASML's 30%. Tom's Hardware estimated that the full one-terawatt goal would need about 12,600 scanners of all kinds. That is their arithmetic, not ASML's.

07 What we know today

27 September 2026.

These are the steps every fab has to go through. Each one is coloured by what the public record showed on this date. Amber: said by Tesla, SpaceX or Musk. Blue: in a filing or a partner's release. Grey: we found no report.

  • Site: Grimes County named, 6 August 2026. Research fab groundbreaking in Austin, April 2026.
  • Money: the S-1 says capital expenditure has not been determined.
  • Process: Intel 14A. Intel's own release names it a strategic partner.
  • People, power and water: at least 3,000 jobs and the Gibbons Creek Reservoir, both as stated.
  • Tools and output: we found no reported tool order and no reported first wafer.

This is what is known, not a prediction. The next edition will set the new facts beside these ones.

Electrek (6 August 2026); SpaceX Form S-1; Intel Q1 2026 earnings release. "No report found" is dated to our search on 27 September 2026.

08 Where to go next

Inside the building.

Sources, in order of use:

Edition 1, 27 September 2026. Next review: the week after Tesla's Q3 2026 results.