Housing production · design space · pre-gate
Every housing production system answers the same sixteen questions. This page holds one answer set per question — 66 alternatives in all — the 22 couplings hypothesised between them, and the 19 systems that have actually been run or proposed, each recorded as one combination. Pick answers and the board reports which couplings hold, which break, and whether any recorded case has ever run that set.
Nothing here is a finding. Every coupling is a hypothesis about interdependence and carries a grade — 18 Untested, 4 Contested. The layers and the rank order are computed from the coupling register, not assigned. Where a coupling is contradicted it is contradicted as assigned, which may mean the assignment is wrong rather than the coupling.
And the figures on this page are sourced but not graded. 30 of them are quoted from a named source that no row in this project’s evidence register carries, so they do not have the grade and review date every claim on the rest of this site does. They are shown because the cases are worth recording with their numbers attached, and marked because the footer below promises grading that this page alone does not provide. Promoting one means opening its source and grading it.
01The slots, as layers
Layer and order are derived from the coupling register, not assigned: a slot sits beneath every slot that depends on it, and the 5 layers below are the longest chain of prerequisites underneath each one. Edges light up for the combination selected in the next section. S16 is a meta-slot about the path rather than the system and is not layered.
The controls above need JavaScript. Without it the diagram, the case matrix, the rank order, the coupling register and the sources below all still read; only the live selection does not.
02One answer per question
One answer to each question. Pick two only where a system carries both — HUD-code approves the type and the plant, so it carries two answers in that slot. The letters mark where an alternative comes from: L Lintel, C1–C3 the three cold reads, H history, Q the status quo.
What may be built, and is the rule the same everywhere?
What is approved: each house, the design, the plant, or the checker?
How is conformance checked, and by whom?
Who decides a house may go on this parcel, and by what kind of rule?
How are incumbents (existing owners, neighbours, localities) brought to accept new housing?
Where do buildable parcels come from?
Where does the design of a given house come from?
What physically is the house and where is it made?
How do parts from different makers fit together?
Who builds it, organised how?
How does the house get onto the parcel and become occupiable?
Who does the work and how are they employed and trained?
How are orders generated, and what keeps them continuous?
How is the house paid for, and what is it legally while being paid for?
Who is liable for defects and carries the warranty?
Who acts first to change the system?
No combination selected
Load a recorded case, or pick an answer to any question.
Distance is the number of slots where the case's recorded answer differs from the selection; only slots the case has on record are compared.
0319 cases · 1 baseline · 9 historical · 5 running · 4 proposals
Each row is one combination that was run, is running, or has been proposed. Cells in italic are this session's reading of the record rather than a cited statement — 130 of the assignments are marked that way; an em dash means no record. Cells that match the current selection are marked.
| Case | Outcome | S01 Construction standard | S02 Approval object | S03 Checking mechanism | S04 Siting authority | S05 Assent mechanism | S06 Land supply | S07 Design origination | S08 Product architecture | S09 Interface standard | S10 Production organisation | S11 Delivery and site assembly | S12 Workforce | S13 Demand mechanism | S14 Title and finance | S15 Defect liability | S16 First mover |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Baseline | |||||||||||||||||
US site-built status quoongoing · United StatessummaryDominant production system. 7.4 months start-to-completion in 2025 per register E-002. Productivity plateau since 1970 per register E-015.SRC-01; SRC-02; SRC-21:E-002; SRC-21:E-015 | dominant | Local variant | Each project | Public review | Local discretionary | Compensation | Developer subdivisions | Plan library | Stick | De facto open | Fragmented subs | Serial trades | Itinerant trades | Project-by-project | Construction loan | Builder | — |
| Historical | |||||||||||||||||
HUD-code manufactured housing, 1976-19971976-1997 · United StatessummaryFederally preempted construction standard; siting left local; chattel title. Shipments peaked at 373,143 in 1998, just after this period, and stood at 102,738 in 2025 — still under a third of peak — per register E-012. Cheapest new housing produced.SRC-21:E-012; SRC-21:E-051; SRC-21:E-132; SRC-19 | survived-quarantined | National | Type + Plant | Private agency | Local discretionary | None / override | Land-lease | Catalog | Chassis | Proprietary | Many plants | Dealer delivery | Factory + crews | Dealer inventory | Chattel | Manufacturer | National gov |
HUD-code industry, 1998-2004 (securitised chattel episode)1998-2004 · United StatessummaryShipments 373,143 (1998) to 130,748 (2004), a 65% fall during the largest site-built boom in decades; repossession glut (Oakwood, Conseco). Varies one slot from C01: title and finance.SRC-21:E-012; SRC-21:E-129 | collapsed | National | Type + Plant | Private agency | Local discretionary | None / override | Land-lease | Catalog | Chassis | Proprietary | Many plants | Dealer delivery | Factory + crews | Dealer inventory | Securitised chattel | Manufacturer | National gov |
Operation Breakthrough (HUD)1969-1976 · United Statessummary22 producers from 236 proposals; ~2,800-2,900 prototype units at nine sites; ~$72M federal cost. GAO: market aggregation not performed as anticipated; continuous demand not achieved; subsidised programmes suspended at start of 1973.SRC-04; SRC-05 | ended | Local variant | Each project | Public review | Local discretionary | None / override | Gov-assembled | Plan library | Volumetric + Panelised | Proprietary | Many plants | Set + button-up | Mixed | Subsidy | Gov loan | Builder | National gov |
Lustron Corporation1948-1950 · United Statessummary2,498 enamelled-steel houses; $12.5M initial RFC loan, over $37M total; builder-dealer network; lost money on each house; RFC recalled loans 1950; local ordinances (steel chimneys) obstructed placement.SRC-06; SRC-07 | failed | Local variant | Each project | Public review | Local discretionary | None / override | Existing stock | Catalog | Panelised | Proprietary | Integrated firm | Set + button-up | Mixed | Dealer inventory | Gov loan | — | Company |
Katerra2015-2021 · United StatessummaryAbout $2B raised (SoftBank-led); Chapter 11 June 2021 with liabilities $1-10B. Company-stated causes: pandemic, loss of bonding after Greensill's insolvency, inability to raise capital and business.SRC-08; SRC-09 | failed | Local variant | Each project | Public review | Local discretionary | None / override | Developer subdivisions | Catalog | Panelised + Volumetric | Proprietary | Integrated firm | Set + button-up | Mixed | Project-by-project | Construction loan | Builder | Company |
Singapore CORENET e-PlanCheckc.2002-2010s · SingaporesummaryAutomated code checking over bespoke buildings; 'died silently, the reasons are unclear' (Potter, per register E-128). CORENET X soft-launched 2023-12-18 with an Automated Model Checker still 'under development'.SRC-21:E-128; SRC-18; SRC-23 | ended | National | Each project | Auto / written codes | National siting | — | — | — | — | — | — | — | — | — | — | — | National gov |
ICC SMARTcodes2006-2010 · United StatessummaryAutomated checking initiative; ended 2010 for lack of funding per register E-127.SRC-21:E-127 | ended | Local variant | Each project | Auto / written codes | Local discretionary | — | — | — | — | — | — | — | — | — | — | — | Consortium |
Fiatech AutoCodes2011-2015 · United StatessummaryProof of concept Jan 2012 on IBC Ch. 10-11 with 13 jurisdictions; identical 137-sheet set drew 1 to 43 issues; 'review inconsistency is the norm'; scaled back.SRC-21:E-125; SRC-21:E-126 | pilot-ended | Local variant | Each project | Auto / written codes | Local discretionary | — | — | — | — | — | — | — | — | — | — | — | Consortium |
NYC FORNAX / ICC pilot2005 · United StatessummaryCompleted pilot reported in AECbytes (Khemlani, 2005-10-26); no adoption; rests on one vendor-adjacent trade article, per register E-080/E-081.SRC-21:E-080; SRC-21:E-081 | pilot-ended | Local variant | Each project | Auto / written codes | Local discretionary | — | — | — | — | — | — | — | — | — | — | — | Consortium |
| Running | |||||||||||||||||
Honolulu CivCheck pre-application check2026- · United StatessummaryJurisdiction mandates an automated pre-application check from 2026-09-01 (register E-117): a city buying the automation itself.SRC-21:E-117 | started | Local variant | Each project | Auto / written codes | Local discretionary | — | — | — | — | — | — | — | — | — | — | — | State statute |
Japan industrialised housing (Sekisui House, Daiwa House and peers)1960s- · JapansummaryType conformity certification (Art. 68-10) and manufacturer certification (Art. 68-11) omit building-confirmation review of covered provisions; 13 national use zones; 114,729 prefab completions FY2023 = 14.3% of all starts (JPA).SRC-13; SRC-14; SRC-15 | running | National | Type + Plant | Private agency | Local envelope | None / override | Existing stock | Catalog | Panelised | Proprietary | Integrated firm | Set + button-up | Factory + crews | Project-by-project | Mortgage at delivery | Manufacturer | National gov |
Sweden factory-built single-family housing1970s- · SwedensummaryMunicipal planning monopoly (PBL 1 kap. 2 §); national building regulations; catalog houses the norm. Prefab share widely cited at 80%+ but NOT verified in this session.SRC-16; SRC-24 | running | National | Each project | Public review | Local envelope | None / override | Gov-assembled | Catalog | Panelised | Proprietary | Many plants | Set + button-up | Factory + crews | Project-by-project | — | — | National gov |
Singapore HDB with PPVC1960- · SingaporesummaryPublic developer with standing demand; state as landowner; PPVC required on selected non-landed residential GLS sites since 2014-11-01 (BCA). Resident share in HDB flats NOT verified in this session.SRC-17; SRC-18 | running | National | Each project | Public review | National siting | State landowner | Gov-assembled | Plan library | Volumetric | Proprietary | Many plants | Set + button-up | Mixed | Public order | Gov loan | State | National gov |
California ADU state preemption2017- · United Statessummary2016 AB 2299 / SB 1069 preempted local ADU rules; permits from just over 1,000 (2016) to over 24,000 (2022); 80,000+ since 2016 (BPC citing HCD; CA YIMBY 83,865). 2019 bills not verified.SRC-10; SRC-11; SRC-12 | running | State-uniform | Each project | Public review | State preemption | Incumbent gains | Existing stock | Bespoke | Stick | De facto open | Fragmented subs | Serial trades | Itinerant trades | Project-by-project | — | Builder | State statute |
| Proposals — combinations nobody has run | |||||||||||||||||
Lintel (as recorded in project notes)2026 · United StatessummaryHUD-code type as vehicle; conformance authority (certify the checker); preempting siting standard as the missing instrument; private matching layer; incumbent homeowners as suppliers; insured checker liability.SRC-21 | proposal | National | Type + Plant + Checker | Private agency + Auto / written codes | National siting | Incumbent gains | Existing stock | Catalog | Chassis | Proprietary | Many plants | Set + button-up | Factory + crews | Private aggregation | Mortgage at delivery | Checker | Company |
Cold read 12026 · United StatessummaryOpen national platform; type and plant certification; by-right siting with site profiles; ~150 regional plants; sold like a car; public buyer of last resort.SRC-22 | proposal | National | Type + Plant | Auto / authored rules + Self-cert, audited | Local envelope | None / override | Lot production | Catalog | Volumetric | Formal open | Plants on standard | Parallel set | Factory + crews | Public order + Project-by-project | Mortgage at delivery | Manufacturer | National gov |
Cold read 22026 · United StatessummaryApprove the design once; hybrid cores plus panels; digital lot passport with local envelopes; open interface standard; many small factories; mortgage at delivery; countercyclical public buyer.SRC-22 | proposal | National | Type + Plant | Auto / authored rules + Self-cert, audited | Local envelope | None / override | Existing stock | Catalog | Cores + panels | Formal open | Plants on standard | Parallel set | Factory + crews | Project-by-project + Public order | Mortgage at delivery | Manufacturer | National gov |
Cold read 32026 · United StatessummaryCertification replaces permitting; lot certified separately; site-ready-lot industry; helical piles; several hundred plants; federal standing counter-cyclical order book.SRC-22 | proposal | National | Type + Plant | Auto / authored rules + Self-cert, audited | National siting | None / override | Lot production | Catalog | Volumetric | Formal open | Plants on standard | Parallel set | Factory + crews | Public order + Project-by-project | Mortgage at delivery | Manufacturer | National gov |
04Derived, not assigned
Rank rule: layer ascending (how many prerequisite slots sit beneath it), then leverage descending (how many slots depend on it); both derived from the requires and enables couplings, not assigned; S16 is a meta-slot about the path and is not ranked.
| Rank | Slot | Layer | Leverage | Question | Requires | Enables | Alternatives |
|---|---|---|---|---|---|---|---|
| 1 | Assent mechanismS05 | L0 | 9 | How are incumbents (existing owners, neighbours, localities) brought to accept new housing?The political complement to S04; a rule can exist and still be resisted. | — | Siting authority | None / override · Incumbent gains · Compensation · State landowner |
| 2 | Construction standardS01 | L0 | 7 | What may be built, and is the rule the same everywhere?Covers the technical code only; who approves against it is S02, who checks is S03. | — | Approval object, Interface standard, First mover | Local variant · State-uniform · National |
| 3 | Title and financeS14 | L0 | 4 | How is the house paid for, and what is it legally while being paid for?Chattel vs real property; construction loan vs mortgage at delivery; who carries inventory risk. | — | Demand mechanism | Chattel · Construction loan · Mortgage at delivery · Gov loan · Securitised chattel |
| 4 | Land supplyS06 | L0 | 1 | Where do buildable parcels come from?Stock vs flow of placeable land; distinct from who may site on it (S04). | — | Delivery and site assembly | Existing stock · Developer subdivisions · Lot production · Land-lease · Gov-assembled |
| 5 | Siting authorityS04 | L1 | 8 | Who decides a house may go on this parcel, and by what kind of rule?Zoning, setbacks, use; distinct from the construction code (S01). | Assent mechanism | Approval object, Demand mechanism | Local discretionary · Local envelope · State preemption · National siting |
| 6 | Interface standardS09 | L1 | 2 | How do parts from different makers fit together?Proprietary, de facto open, or formally open; independent of S08. | Construction standard | Production organisation, Delivery and site assembly | Proprietary · De facto open · Formal open |
| 7 | Approval objectS02 | L2 | 4 | What is approved: each house, the design, the plant, or the checker?The unit that carries the approval. More than one may apply (e.g. type and plant). | Construction standard, Siting authority, First mover | Checking mechanism, Design origination, Defect liability, First mover | Each project · Type · Plant · Checker |
| 8 | Demand mechanismS13 | L2 | 3 | How are orders generated, and what keeps them continuous?Speculative, dealer inventory, private aggregation, subsidy, public standing order. | Siting authority, Title and finance, First mover | Product architecture | Project-by-project · Dealer inventory · Private aggregation · Subsidy · Public order |
| 9 | Production organisationS10 | L2 | 0 | Who builds it, organised how?Fragmented subs, one integrated firm, many plants with or without a shared standard. | Interface standard | — | Fragmented subs · Integrated firm · Many plants · Plants on standard |
| 10 | Product architectureS08 | L3 | 2 | What physically is the house and where is it made?Stick, chassis, volumetric, hybrid, panel, printed. | Demand mechanism | Workforce, Defect liability | Stick · Chassis · Volumetric · Cores + panels · Panelised · Printed |
| 11 | Checking mechanismS03 | L3 | 1 | How is conformance checked, and by whom?Human vs private vs automated; distinct from what is approved (S02). | Approval object | Delivery and site assembly | Public review · Private agency · Auto / written codes · Auto / authored rules · Self-cert, audited |
| 12 | Design originationS07 | L3 | 1 | Where does the design of a given house come from?Bespoke, builder library, or certified catalog; independent of physical architecture (S08). | Approval object | Defect liability | Bespoke · Plan library · Catalog |
| 13 | Delivery and site assemblyS11 | L4 | 0 | How does the house get onto the parcel and become occupiable?Foundation, transport, set, connection, final inspection sequencing. | Checking mechanism, Land supply, Interface standard | — | Serial trades · Set + button-up · Parallel set · Dealer delivery |
| 14 | WorkforceS12 | L4 | 0 | Who does the work and how are they employed and trained?Itinerant trades vs factory employees plus set crews vs mixed. | Product architecture | — | Itinerant trades · Factory + crews · Mixed |
| 15 | Defect liabilityS15 | L4 | 0 | Who is liable for defects and carries the warranty?Builder, manufacturer, certified checker, or the state. | Approval object, Design origination, Product architecture | — | Builder · Manufacturer · Checker · State |
| — | First moverS16 | meta | — | Who acts first to change the system?Meta-slot about the path, not the system; excluded from layer computation. | Construction standard, Approval object | Approval object, Demand mechanism | National gov · State statute · Company · Consortium |
0522 hypotheses · 18 Untested, 4 Contested
Every coupling is a hypothesis about interdependence. All 22 started Untested; 4 — K04, K12, K13, K16 — were regraded Contested on the first pass because a case that is running violates them as assigned. Each row names the cases that suggest it and the evidence that would move it.
A coupling violated by a case that is running or dominant is contradicted by the record as assigned; a coupling violated by a case that failed is consistent with it. Cases that survived quarantined, or started too recently to count, are listed on the coupling rather than here. None of this is proof — every case differs on several slots at once — but a contradiction is a reason to regrade the coupling or to re-read the assignment.
Approval attached to a type or plant is void across jurisdictions unless one standard applies everywhere.
A certified type under discretionary local siting is legal but unplaceable: it gets quarantined.
Automated checking has ended every time it was run over bespoke buildings against human-written codes; it has never been run over the residual site check for a certified type.
A fixed-cost plant needs continuous demand; the mechanism that failed differs in each US case, and Japan runs on private orders, so 'non-speculative' is not the condition — 'continuous' is.
Chassis homes financed by securitised chattel loans with loosened underwriting produced a repossession glut and a 65% shipment fall during a site-built boom.
A home that is legally a vehicle (permanent chassis) is titled and financed as one; real-property mortgage at delivery cannot attach while the chassis defines the product.
A published interface standard lets many makers compete on one product and lets learning compound; no US factory-housing case has run it, while site-built runs on a de facto one.
An interface standard only holds if the approval regime is uniform; local code variation breaks interchangeability.
A private matching layer is only as good as the placement test: permission recorded is not placement tested.
A public standing order is only as durable as the political commitment behind it; one decision can withdraw it.
Certifying the checker needs a statute or a jurisdiction that accepts an outside determination in place of first-pass review.
An integrated cost base cannot idle through speculative demand swings; Japan's integrated makers on private orders are the counterexample unless their demand is shown continuous.
Locally set objective envelopes drift back toward discretion unless a higher level constrains them.
Preemption that gives incumbents a gain passed and produced output; preemption that only overrides carries the assent cost.
A one-day set with a week of button-up presumes a lot serviced before the order and standard utility interfaces.
A catalog saves time only if its entries are pre-approved; a catalog without type approval still meets per-house local review.
Deposit-paying buyers need financing that closes at delivery; without it the order book converts to nothing.
A continuous in-plant quality record lets the site inspection sequence collapse to one visit.
A company can only start where the statute already exists; that is why the HUD-code type 'waits on no gates'.
A factory workforce presupposes a factory product.
Insured checker liability presupposes a certified checker whose determination carries legal weight.
A manufacturer warranty presupposes a manufacturer: a catalog or factory product.
0625 sources · 4 unread leads
A source marked read: no is a lead that was not opened, and nothing graded rests on one. Rows in this project's own evidence register are cited as SRC-21:E-nnn and resolve there.
7.6 start-to-completion; built-for-sale 7.6; owner-built 15.1 one figure on this row is retired on this site (C-016) and is not printed here
2025: 7.5 months single-family, 16.5 months 2+ units; 2023 records 8.6 and 17.1
Primary table avg_starttocomp_cust.xlsx; binary not opened in this session
Quoted: 236 proposals, 22 selected; ~$72M federal cost; market aggregation not performed as anticipated; 1973 suspension of subsidized programs
22 producers; more than 2,900 prototype units; nine sites; Phase III 18,000 of 25,000 intended by March 1976
$12.5M RFC loan; bankrupt 1950 when RFC recalled loans; unable to sell enough houses to profit
2,498 houses 1948-1950; builder-dealers; over $37M in loans; production stopped 1950-06-06; local zoning obstacles (steel chimneys)
Chapter 11, S.D. Texas; about $2B raised; liabilities $1-10B
Company-stated reasons: pandemic; bonding after Greensill insolvency; capital and business
2016 AB 2299 / SB 1069 preempted local ADU rules; permits just over 1,000 (2016) to over 24,000 (2022); 80,000+ since 2016 (citing HCD)
Advocacy source; 15,334% increase 2016-2022; 83,865 ADUs permitted, attributed to HCD data
SB 477 (2024) renumbered ADU Government Code sections; no permit counts on page
Certification by Minister or designated body; building-confirmation review of covered provisions omitted; manufacturer certification also omits the matching check
13 nationally defined use zones
114,729 prefab completions FY2023 (86 members, 100% response); 14.3% of all new starts; detached 35,844
1 kap. 2 §: planning is a municipal matter; 9 kap. 27 § ten-week limit not retrieved
PPVC definition; required for selected non-landed residential GLS sites since 2014-11-01 (sentence wording not confirmed verbatim); productivity claims are the regulator's own
Soft-launched 2023-12-18; Automated Model Checker 'under development to verify straightforward regulatory requirements'
One Pennsylvania plant: a home every three days; MD, ME, NH, RI 2024 laws against zoning barriers to manufactured homes
High-end HUD-code home 3-4 months construction-to-delivery; about 60 days faster than site-built, depending on backlog
Row ids cited as E-nnn; grades are the register's, not this file's
Proposals P02-P04 are transcribed from this file
Lead only; not read in this session
Lead only for the Swedish prefab share; not read
Lead only; not read