On Digital Architecture

▌ Lecture 06 — 28 April 2026 Raumgestaltung S7 · seminar by Miro Roman · reading Ludger Hovestadt
▌ Applied Virtuality Book Series · a poem of titles

Beyond the Grid EigenArchitecture Printed Physics Quantum City Genius Planet The Powerbook
Domesticating Symbols Symbolizing Existence Coding as Literacy
Atlas of Digital Architecture On Digital Architecture · Books I–III On Digital Architecture · Books IV–VI
▌ Hovestadt · Vol. I With new eyes, things become active and smart.
Book I — The Architect · §SUBJECTS

Ludger Hovestadt led the chair of Computer Aided Architectural Design (CAAD) at ETH Zürich for over two decades. His ten-volume On Digital Architecture is less a software manual than a treatise on how digital culture changes the very objects of architecture — from singular things to numerical, generic, alive structures.

§01

Studio + Chair

Meteora — meteora.ch
Design Studio

Meteora

Hovestadt's design studio — where the numerical thinking lands.

meteora.ch ↗
CAAD ETH — caad.arch.ethz.ch
Chair

CAAD ETH

The chair Hovestadt held — site for the Applied Virtuality program.

caad.arch.ethz.ch ↗
§02

The 10 Books

Hovestadt's ten books sit inside a centuries-long canon: Vitruvius's ten books on the rational, Alberti's ten books on the real, and now Hovestadt's ten on the complex. Each rewrites architecture for a new mathematical scalarity.

The Applied Virtuality Book Series (Birkhäuser) holds Hovestadt's contribution. On Digital Architecture spans ten volumes, currently grouped into two collected editions on Xenotheka.

Applied Virtuality Book Series — Birkhäuser
Series

Applied Virtuality

The full publishing context — every volume in the series.

birkhauser.com ↗
On Digital Architecture I–III — Xenotheka
Reader

Books I–III

Volumes 1–2 collected on Xenotheka — start here.

xenotheka.com ↗
On Digital Architecture IV–VI — Xenotheka
Reader

Books IV–VI

The continuation — collected volumes IV through VI.

xenotheka.com ↗

Direct PDFs (Some of Ludger's books):

On Digital Architecture I–III — Hovestadt constellation map
PDF

Books I–III · PDF

Full Xenotheka rendering — direct download.

open pdf ↗
On Digital Architecture IV–VI — Hovestadt constellation map
PDF

Books IV–VI · PDF

Full Xenotheka rendering — direct download.

open pdf ↗
On Digital Architecture I–III — local PDF
Local PDF

In this folder

The copy already sitting next to this page.

open pdf ↗

The two ancestors: Vitruvius and Alberti — each with their own ten books, each rewriting architecture for their century's scalarity. Plus a video reading.

Vitruvius — Ten Books on Architecture
Predecessor · 1st c. BC

Vitruvius

Ten Books on Architecture — the rational scalarity. Hovestadt's first ancestor.

xenotheka.com ↗
Alberti — On the Art of Building in Ten Books
Predecessor · 15th c.

Alberti

On the Art of Building in Ten Books — the real scalarity. Hovestadt's second ancestor.

xenotheka.com ↗
Miro Roman reading Vitruvius / Barbaro
Reading · Video

Reading the canon

Miro Roman walks through Vitruvius (with Barbaro's commentary) on Xenotheka.

youtube.com ↗
▌ Hovestadt · Vol. I These books feel alienated to language. As they feel alienated to the digital world. And they try to find a new stand.
Book I — §VOICES
§03

The One, the Two, the Three, the Four

Hovestadt reads architectural thinking through numerical structures — each level adds a different relation, a different way of articulating the world.

1
Singularity
The One
Reference / origin. Central point. Sun, public, nature. Anchor of thinking — defines a field rather than an object.
2
Duality
The Two
Distinction / opposition. Linear. Time / space, object / subject, line / circle. Analytical thinking — separating concepts.
3
Trivium
The Three
Articulation / mediation. Triadic. Grammar · Logic · Rhetoric. Encoding · Coding · Decoding. The language of architecture — how ideas are expressed and negotiated.
4
Quadrivium
The Four
System / relation / cycle. Circular. Air · Fire · Earth · Water. Inner / Outer · Past / Future. Idea · Memory · Picture · Vision. World-building — relational systems and environments.
Hovestadt — Numerical Structures of Thinking
▌ FIG. Hovestadt — Numerical Structures of Thinking · 1 / 2 / 3 / 4
▌ Hovestadt · Vol. I The reference is the Sun, not Nature, not Earth.
Book I — §TURN
▌ Hovestadt · paraphrasing Koolhaas You can't improve by doing better.
Book I — §THREATS · on Junk Space & the Generic City
§04

Watch

Farewell lecture — ETH video portal
Lecture · Video

Farewell Lecture

Hovestadt's emeritus lecture, recorded at ETH Zürich.

video.ethz.ch ↗
ETHZ CAAD — YouTube channel
Channel

ETHZ CAAD

Talks, projects, dissertations from the chair.

youtube.com ↗
§05

Objects are alive

One question worth carrying across the lectures: how do objects breathe?

▌ Hovestadt · Vol. I I am not what I can DO. I am what I can THINK about.
Book I — §PUBLIC
▌ Hovestadt · Vol. I I am not talking about technology, this distant thing which is definite. I am talking about techniques, which can become me. I incorporate techniques. I embody techniques.
Book I — on Techniques
§06

Three crossings

S7 · Raumgestaltung · 06 / Digital Architectonics 26.04.28 · Hovestadt