Jang Gi-in's Changho | Where It Comes Apart

About This Page

Jang Gi-in, Changho (Korean Architecture Compendium I), Boseonggak. This page is based on the reprint edition of August 20, 2019.

The reprint is a straight reprint of the first edition, untouched. Proof: the author's bio still reads, unchanged, "Current Representative, Samseong Architectural Design Office" (現 三成建築設計士事務所 代表).

If you're reading the first edition, the page numbers may differ.

This covers the entire main text, pages 9–88, and the entire appendix, pages 89–234.

A caveat on the edition. There's a library holdings record listing the 1983 edition at 86 pages. This edition runs 238 pages.

86 pages roughly matches the main text alone; 238 pages includes the appendix as well.

I haven't yet confirmed when the appendix was added. If it wasn't in the first edition, items 45–55 below may not be the first edition's own author's writing.

I'll correct this once confirmed. I noted, in page order, every spot that snagged me while reading. Since this is a book worth keeping close for years, I made this list so you can check it against the book as you read. It's not an essay — it's a tool.

This isn't exhaustive. How closely I read varies from spot to spot. The appendix alone runs over a hundred pages of plates, and I've only logged the spots that caught my eye while cross-checking against the main text.

I'll keep adding to it.

Marks

Numbers are fixed. Existing numbers never change even as entries are added. The number reflects the order an item was added; the table itself is ordered by page. An item added later keeps its later number, but sits in its proper place by page.

Updated: September 20, 2026 — Added items 56–62. Moulding name count, gyeokja-gyo-sal joinery, minpaemun/flash door, the first sentence on maengjangji, the character 柴 in "bindi," Figure 7-3 ③, "wangjamun" in the appendix table of contents.

The List

A. "Bit-sal" Points to Two Different Changho

A single name points to two entirely different changho.

Spots that mean 45°

Spots that mean triangular

Pages 203 and 205 are two pages apart. Same name, different changho. A changho crossed at 45° that produces diamond cells, and a changho crossed in three directions that produces triangular cells. To a hand that actually joins them, these are entirely different objects.

Even the meaning of the word "bit" shifts from spot to spot

Split apart on page 44, and grouped together on page 41 and in the appendix.

Why This Happens

Because the name was hung on the pattern, not the joinery.

"Bit" means tilted. Set at 45°, it's tilted; set at 30°, it's also tilted. Looking only at the pattern, both are bit-sal.

Hang the name on the joinery instead, and they split apart. A 45° gyo-sal runs its slats in two directions, crossed with a half-lap. A changho that produces triangular cells runs its slats in three directions, joined with a triple-notch. Since the hands do different work, the names should differ too.

This book wavers right at that spot. Which is exactly how the same name ends up pointing to different changho two pages apart.

B. One Changho, Six Names

Set slats at 30° and place a vertical slat at their crossing points, and the cells come out as equilateral triangles. This single changho is called all of the following.

The first half of the name splits into sotgeul, bit, semo, samgak, and yukmo; the second half splits into sal, sotgeul-sal, and soseul-sal.

C. Sutdae-sal Joinery (page 35)

This one is hard to fit into a single table line, so I've written it out separately.

What the book says

Page 35, section 4-2. Where slat ends meet at right angles, they're joined with a short tenon joint, and one or two of the middle horizontal slats are made as long slats, run across to the left and right stiles, and joined with a long tenon.

It goes on to say that, at this point, the top and bottom of the long horizontal slat are usually made symmetrical.

Do that, and it isn't sutdae-sal anymore

Run a single continuous slat through, and the pattern breaks at that row. What had been interlocking, offset row by row, stops right there, splitting into a top half and a bottom half. What's left is a door panel with a middle divider.

Sutdae-sal is a changho joined by breaking the slats apart. The pattern only exists because the break points are offset. A slat running straight through can't coexist with that principle.

Why It Ended Up Written This Way

Line up three spots, and the sequence becomes visible.

1. Page 34 — "The construction method of sutdae-sal changho is entirely identical to that of aja-changho."
2. Page 31 — "In aja-sal, if the middle horizontal slat runs long through to the left and right stiles, each slat is fixed sturdily."
3. Page 35 — "In sutdae-sal too, one or two middle horizontal slats are run as long slats across the left and right stiles."

This reads as if the author first declared sutdae-sal identical to aja, then simply carried aja's rule over and wrote it into the sutdae-sal entry.

The sentence that follows points the same direction. Make the top and bottom of the long horizontal slat symmetrical. Someone actually joining the pattern doesn't concern themselves with top-bottom symmetry — offsetting it is the whole point of the job. Top-bottom symmetry is the language of someone who divides the middle and matches the top to the bottom.

That said

It's possible this really was done this way on a large door. It could also differ by region or era. What's recorded here is only what I've confirmed with my own two hands.

Which is exactly why this is marked △, not ●.

The Author of This Book

Jang Gi-in (張起仁, 1916–2006). Pen name Hoam (虎巖).

A biography appears at the back of the book. He graduated from the Architecture Department of Gyeongseong Higher Technical School in 1938. He served as President of the Korean Institute of Registered Architects and Vice President of the Architectural Institute of Korea, and is listed as Representative of the Samseong Architectural Design Office. He also lectured at several universities.

He was an architect, not a carpenter.

And the bio contains this line: Former Member, Ministry of Education's Committee on Architectural Terminology. He's also listed as a member of the Economic Planning Board's committee for standard construction cost estimates, and a review committee member for the Bureau of Standards under the Office of Industrial Advancement.

This is a book written by someone who sat on the very committee that set architectural terminology as institutional policy.

The terminology work didn't end with this single book, either. He published a running series, "Scraps of Architectural Terms," in the Journal of the Architectural Institute of Korea. He spent a long time gathering and organizing Korean-language architectural terms.

Seen that way, the character of this list changes somewhat. It's less a collection of one person's mistakes, and closer to the trace left by a project that tried to gather scattered job-site language from the outside and organize it into a standard.

The practical descriptions are accurate — dimensions and joints get verified against drawings and physical objects. What wavers is the naming. There's no physical object against which a name can be verified. Words that came out of a carpenter's mouth and characters that came down through books end up listed side by side, with no way to tell them apart.

It also has to be weighed that one person gathered and organized this much material, alone, in 1983 — think about what would even have been available to reference at the time.

The 2019 reprint reproduced the first edition exactly, untouched — thirteen years after the author's death. It's unlikely to ever be corrected going forward. That's exactly why this list exists.

What This Book Gets Right

To avoid any misunderstanding: there are passages that are stated clearly and have nothing off about them.

The rule splitting semo from yukmo is one. In 30° sotgeul-sal, each section is a diamond. Set a vertical slat at the slats' crossing point, and you get an equilateral triangle — that's semo-sotgeul-sal.

Set it between crossing points, and you get a regular hexagon — that's yukmo-sotgeul-sal.

The joinery is described correctly too. A triple crossing gets a triple-notch joint, a quadruple crossing point gets a quarter-notch joint, and a vertical slat gets a half-lap joint. Detailed drawings are given member by member.

That said, this is specifically about the soseul-sal entry on page 46. Applying the same quarter-notch to every slat in the gyeokja-gyo-sal on page 45 is a different, mistaken matter (see item 57).

The chain of dimensions also holds up. Set the frame's thickness at half the door lintel's thickness, and the frame's width and the slat size are derived from there.

The direction of a half-lap — the rule that horizontal slats are notched from the back and vertical slats from the front — is also accurate.

Passages like these still hold up today. The problem is the naming.

Appendix Structure

I've transcribed this for you to use when cross-checking. Only items 4, 10, and 11 have made it onto the list above so far.

Items 3–6 (wanja-chang, wanja-mun, aja-chang, aja-mun, pages 110–163) run more than fifty pages of plates I haven't cross-checked yet. Item 7 is the same.

Updated September 20, 2026