Fix form-language template: vernacular strata, natural materials default

Sheffield/Harbor House drafting exposed two gaps: the template let a
historical stratum be anchored by a single celebrated/architect-authored
building (Park Hill) instead of a genuine building culture, and let
modern structural materials (reinforced concrete) into the vocabulary
without requiring a structural-necessity justification. Tightens the
HISTORICAL_STRATA placeholder guidance, the vocabulary/negative-constraint
instructions, and the Appendix instruction to close both gaps.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

templates/form-language-prompt-template.md

@@ -1,35 +1,46 @@
 # Form-Language Prompt Template
 
 *A reusable prompt for generating a project-specific architectural
-form-language grammar module, in the style pioneered for this project.*
+form-language grammar module.*
 
 ## Provenance
 
-This template generalizes the two-step prompting process Nikos Salingaros
-used to produce `ref/Ecuadorian_Form_Language_Grammar.md`
-(`docs/salingaros-form-language-prompt.md` — his initial and follow-up
-prompts), collapsed into a single one-shot prompt with placeholders for
-region, climate, site, and building typology. The required output shape
-(§0–§11 + appendix below) mirrors the structure of that worked example,
-which should be used as the calibration reference for filling this
-template in and for judging any grammar it produces.
+This template is self-contained — everything needed to run it is in the
+"Placeholders" and "The prompt" sections below. This section and "Usage
+notes" are background only, safe to skip.
+
+The template generalizes a two-step prompting process Nikos Salingaros
+used to produce a form-language grammar for a National Museum of Ecuador
+project (his initial exploratory prompt, then a follow-up narrowing
+scope), collapsed here into a single one-shot prompt with placeholders for
+region, climate, site, and building typology. That original worked
+example and his raw two-step prompts are project-specific files from the
+originating repository and aren't included with this template; §0–§11 +
+appendix below is this template's own self-sufficient output shape, not
+dependent on that example.
 
 The theoretical basis is Salingaros' *pattern language + form language =
-adaptive design method* (`ref/Salingaros-Chapter-11-Two-Languages-for-Architecture.md`):
-a pattern language alone cannot connect to built form without a
+adaptive design method*, set out in Chapter 11, "Two Languages for
+Architecture," of his book *A Theory of Architecture* (2006; revised
+2014): a pattern language alone cannot connect to built form without a
 complementary form language of geometric/tectonic rules. This template
-generates that second, complementary document.
+generates that second, complementary document. It is meant to be paired
+with a pattern-language module such as Christopher Alexander, Sara
+Ishikawa, and Murray Silverstein's *A Pattern Language* (1977), from which
+a project-specific subset of patterns is typically curated.
 
 ## What this produces
 
 A structured **grammar document**, not images and not a narrative — a
 module meant to be handed, alongside a pattern-language module, a project
 brief, and a spatial-chassis module, into a *later* prompt that asks an
-LLM to write the experiential design narrative (see the paper's Section
-4.2 approach, `ref/buildings-15-02400-v2.txt`). Color and ornament are
-left as a menu of selectable registers/packages rather than a single fixed
-choice, so that later narrative/image generation can sample distinct
-combinations and a human can select among them.
+LLM to write the experiential design narrative (see Section 4.2 of Postle,
+B.; Salingaros, N.A. "LLM and Pattern Language Synthesis: A Hybrid Tool
+for Human-Centered Architectural Design." *Buildings* 2025, 15, 2400).
+Color and ornament are left as a menu of selectable registers/packages
+rather than a single fixed choice, so that later narrative/image
+generation can sample distinct combinations and a human can select among
+them.
 
 ## Placeholders
 
@@ -44,7 +55,7 @@ instruction at all.
 | `{WIDE_REGION}` | The broad cultural/geographic region to draw form vocabulary from — narrow enough that its history is genuinely coherent (so the strata actually relate to one another), broad enough to give real stylistic range; usually a country or a historically-linked macro-region, not a continent | Ecuador (and neighboring Latin America for the "neighbor techniques" package) |
 | `{FIXED_SITE}` | The specific city/site the climate script must be fixed to | Quito, Ecuadorian sierra |
 | `{CLIMATE_SEED_FACTS}` | Known climate facts to ground the research (latitude, altitude, temperature range, rainfall pattern, sun/UV character, seasonality or lack of it) — prevents hallucinated climate data | ≈0.2° S / ≈2,850 m; 9–22 °C year-round; ~1,000–1,250 mm/yr rain, two peaks; near-zenith sun, high UV; no seasons |
-| `{HISTORICAL_STRATA}` | The historical/cultural strata to synthesize across, oldest to newest (or `(let the model propose)`). Not every region has an indigenous or pre-colonial stratum in the sense the Ecuador example does — for a region without one, list whatever historical building cultures it does have instead (e.g. vernacular farmhouse, Roman, medieval, renaissance, industrial-era) rather than forcing an indigenous/colonial framing onto it | indigenous wooden/conical-roof structures; pre-Columbian stone monumental; early colonial wood/earth; later colonial baroque |
+| `{HISTORICAL_STRATA}` | The historical/cultural strata to synthesize across, oldest to newest (or `(let the model propose)`). Not every region has an indigenous or pre-colonial stratum in the sense the Ecuador example does — for a region without one, list whatever historical building cultures it does have instead (e.g. vernacular farmhouse, Roman, medieval, renaissance, industrial-era) rather than forcing an indigenous/colonial framing onto it. Each stratum must name a **building culture** — an ordinary construction tradition recurring across many buildings — not a single celebrated or architect-authored structure: a region's industrial-era stratum, for instance, usually means its ordinary workshop-houses, mill housing, and tenement factories, where industrial and residential use routinely overlapped in the same buildings, not one landmark 20th-century showpiece | indigenous wooden/conical-roof structures; pre-Columbian stone monumental; early colonial wood/earth; later colonial baroque |
 | `{SCALE_NOTES}` | Programmatic/scale notes that affect massing (approx. size, public vs. civic character, number of principal volumes) | ~25,000 m² minimum, high-visitation civic building |
 | `{DOWNSTREAM_MODULES}` | What other prompt modules this will be combined with later (fixed boilerplate unless the project's pipeline differs) | brief constraints, spatial chassis |
 
@@ -74,6 +85,19 @@ building, site, or tradition you name as drawn from your training-data
 familiarity, not from verified research, and say so plainly rather than
 presenting recollection as verified fact.
 
+**Default to natural, traditional materials.** The vocabulary (§3) should
+default to natural, traditional materials — stone, brick, timber, earth,
+tile — drawn from {WIDE_REGION}'s own building cultures. Modern
+structural materials (reinforced concrete, steel) belong in the
+vocabulary only where {TYPOLOGY} genuinely cannot achieve its required
+spans, loads, or heights without them, not as an independent aesthetic
+stratum or a source of decorative expression in their own right. Where
+they are included, express them honestly as structure — an honestly
+exposed frame, not concrete dressed up to imitate a natural material, and
+not hidden behind an applied natural-material skin either — and justify
+each such element in §3 by the specific structural need, not by
+stylistic preference.
+
 **Fix the climate and site, but not the vocabulary.** The building itself
 is fixed at {FIXED_SITE}: {CLIMATE_SEED_FACTS}. Derive from this a set of
 climate facts and the mandatory design responses they imply (roof form,
@@ -143,7 +167,10 @@ of generated projects stays traceable and comparable.
 3. **Form vocabulary (lexicon)** — elements grouped by tectonic family
    (ground/platform, wall, roof/sky, threshold/in-between, interior, or
    whatever families fit this typology), each tagged with its origin
-   stratum and region, each given a short reusable code.
+   stratum and region, each given a short reusable code. Each element
+   should be natural/traditional material by default; if any element
+   uses a modern structural material instead, tag it as such and state
+   the specific structural necessity that justifies it.
 
 4. **Syntax — combination rules** — numbered, always-apply rules for how
    the vocabulary combines: stratification/ordering logic, relationship
@@ -204,8 +231,11 @@ of generated projects stays traceable and comparable.
     without one; always forbid mixing two color registers in one
     project, more than one figurative ornament episode, evenly
     distributed ornament, literal uncredited copying of a named
-    historical building, and applying any motif flagged in §6 as
-    sacred/ceremonial without the noted consultation caveat).
+    historical building, applying any motif flagged in §6 as
+    sacred/ceremonial without the noted consultation caveat, and using a
+    modern structural material where §3 recorded no genuine structural
+    necessity for it, or disguising one material as another instead of
+    expressing it honestly).
 
 11. **Glossary** — every non-English or specialist term used above,
     defined in one line, to be used verbatim (not paraphrased) by any
@@ -215,10 +245,15 @@ of generated projects stays traceable and comparable.
 {HISTORICAL_STRATA}, list two or three named real buildings, sites, or
 artifact traditions from {WIDE_REGION} that anchor it, as reference
 points — not to be copied, but so a later reader can verify the grammar
-is genuinely grounded in something real. For each one, note briefly
-whether it's a well-documented example you're confident about or a
-plausible-but-unverified recollection — don't present both with equal
-certainty.
+is genuinely grounded in something real. Each precedent should be
+representative of that stratum's wider building culture, not the sole
+reason the stratum exists — if a stratum can only be anchored by one
+celebrated landmark with no supporting ordinary/vernacular examples, that
+is a sign it isn't really a building culture (see the {HISTORICAL_STRATA}
+placeholder note) and should be broadened, merged, or dropped rather than
+listed as-is. For each precedent, note briefly whether it's a
+well-documented example you're confident about or a plausible-but-unverified
+recollection — don't present both with equal certainty.
 
 Scale notes for the project this grammar will serve: {SCALE_NOTES}.
 
@@ -226,26 +261,29 @@ Scale notes for the project this grammar will serve: {SCALE_NOTES}.
 
 ## Usage notes
 
-- The worked example this template generalizes
-  (`ref/Ecuadorian_Form_Language_Grammar.md`) is the calibration
-  reference for level of detail, tone, and coding conventions (its `E#`
-  element codes, `C#`/`G#`/`P#`/`O#` rule codes, `CR#`/`OP#` register/
-  package codes). A generated grammar doesn't need identical codes, but
-  should be at a comparable level of precision and equally traceable.
-- Salingaros' original process was two prompts — an open exploratory
-  first pass, then a follow-up narrowing scope (fix climate to the
-  specific site, keep vocabulary regional, drop a single color/ornament
-  choice in favor of a menu, and reframe the output as a prompt module
-  rather than an image request). This template front-loads that
-  narrowing into one prompt; if the first response still drifts (e.g.
-  proposes a single color and ornament choice, or narrows vocabulary to
-  only the immediate site), send a follow-up correcting just that point
-  rather than re-running the whole prompt.
-- Check the output for fidelity the same way pattern-language narratives
-  are checked (see CLAUDE.md's "Method" step 3): any climate rule,
-  vocabulary element, or precedent that isn't grounded in something real
-  for {WIDE_REGION}/{FIXED_SITE} is a hallucination to catch and
-  regenerate away.
+- Aim for a comparable level of precision and traceability throughout: a
+  short, consistent code per element/rule/register/package (e.g. a
+  letter-plus-number scheme such as `G1`, `G2` for ground-family
+  elements, `W1`, `W2` for wall elements, `R#` for roof, `CR#` for color
+  registers, `OP#` for ornament packages — the exact letters don't
+  matter, only that every reusable item gets one and later prompts can
+  cite it unambiguously). Every rule and vocabulary element should be
+  traceable to a named stratum/tradition within {WIDE_REGION}, not
+  presented as free invention.
+- The two-step process this template collapses into one shot was: an
+  open exploratory first pass, then a follow-up narrowing scope (fix
+  climate to the specific site, keep vocabulary regional, drop a single
+  color/ornament choice in favor of a menu, and reframe the output as a
+  prompt module rather than an image request). This template
+  front-loads that narrowing into one prompt; if the first response
+  still drifts (e.g. proposes a single color and ornament choice, or
+  narrows vocabulary to only the immediate site), send a follow-up
+  correcting just that point rather than re-running the whole prompt.
+- Check the output for fidelity: any climate rule, vocabulary element, or
+  precedent that isn't grounded in something real for
+  {WIDE_REGION}/{FIXED_SITE} is a hallucination to catch and regenerate
+  away, the same way a pattern-language narrative generated downstream
+  should be checked against its selected pattern subset.
 - Salingaros described his original prompt as asking the LLM to "locate
   open-source images of traditional buildings" and synthesize from them.
   It's unclear whether that literally happened, as opposed to the model