Manifesto for a Common Building Language · first public draft · Version of 24 October 2026
Every building, every stakeholder, one open language.
The Common Building Language (CBL) is an open description of buildings. Geometry, quantities, prices, carbon and exchange files follow from it, the same in every tool. Written for people and AI models alike, it works alongside existing BIM, CAD and CAM tools, and adoption proceeds project by project.
Your role
Choose your role, or several, and the page puts first what concerns you.
Formulated by the author, extended across disciplines with artificial intelligence.
The Common Building Language (CBL) and Cascading Style Profiles (CSP) were conceived, formulated and formalised by the author, an architect and associate professor working in architecture and building engineering. The theoretical position of the work, its architectural and engineering substance, its research questions and its conclusions are the author's. The author directed the research at every stage, defining the questions, selecting the fields to be examined, formulating and refining the queries, assessing and correcting the results, and revising every passage of the published texts.
Large language models, principally Claude by Anthropic, served as instruments of interdisciplinary research. Their principal contribution lies outside the author's discipline: surveying the literatures of linguistics, information theory, molecular biology, music theory, software engineering and economics, identifying structural correspondences between these fields and architecture, and preparing syntheses that the author examined, accepted or rejected, and rewrote. In this exchange the models served as a source of inspiration as well as of information. Within architecture and engineering their role was confined to drafting and editing under the author's instruction.
The extent of the work is recorded. The master documents have been revised 1,699 times (whitepaper 1,019, manifesto 376, foundations 258, historical analysis 46), each revision an edit made by the author or at the author's instruction. The published texts have passed through 17 versions since 9 October 2026, each dated and identified by a fingerprint of its wording.
The author's competence lies in architecture, architectural theory and building engineering. In the other fields on which the foundations draw, the author writes as an informed non-specialist, and syntheses prepared with the assistance of language models may contain errors of fact, emphasis or interpretation that specialists in those fields would recognise. The references of the foundations have been checked against publisher, catalogue and DOI records, and those awaiting confirmation are marked. Claims drawn from outside architecture are therefore stated as hypotheses open to correction.
In keeping with academic practice, the work is offered for review. Specialists who identify an error, an omitted source or a stronger argument are invited to report it, and corrections adopted are acknowledged by name in the following version. Researchers in other disciplines are invited to test, extend or contest the foundations jointly, through the challenges and as co-authors of the resulting papers, so that the language is developed openly and in the common interest.
H4 Design to quoteTime from the architect's design to a priced configuration; configuration errors found at quotation; re-entry hours per facade and per square metre, against the target of section 1Take itVote
Overruns and delays
The languageOriginality lies in the composition, where the number of combinations has no practical limit, while cost, time and risk are calculated from known parts before anything is built.
Tested by
PredictabilityDeviation of out-turn cost and completion date from the estimate at contract, and its spread across projectsTake itVote
Change controlTime to assess a change requested after contract and its effect on cost, programme and carbon; disputes arising from changesTake itVote
Options hard to compare
The languageWith a shared description, options are compared on one basis from the first sketch, and cost, carbon and lead time are known while they can still change the decision.
Tested by
ComparabilityAccuracy and effort of counting distinct panel, element and detail typesTake itVote
Multicriteria evaluationCriteria evaluated per option and time to evaluate them; functional information of each target; coverage of the Pareto front across domains, by its hypervolume and the extremes it reaches, with and without profiles that each pursue a single objectiveTake itVote
Portfolio decisionsTime to compare options for several sites or buildings of one owner by cost, carbon, area and return on the same criteriaTake itVote
Slow, costly feasibility
The languageSites once too marginal to study are studied, and the chosen option is already the procurement document.
Tested by
H3 Early-design speedHours per facade option and per competition entry; decisions and hours to reach the selected optionTake itVote
Brief as criteriaShare of a brief's requirements stated as criteria that can be checked; requirements found missing or contradictory before design beginsTake itVote
Developers and investors learn cost, carbon and lead time after the design is fixed, when a change is most expensive. With a shared description, options are compared on one basis from the first sketch, and cost, carbon and lead time are known while they can still change the decision.
Your first step
State the brief of one project in the language and compare the options you receive.
The languageThe language returns those hours to design: as the architect drafts and revises, each option is checked against the brief, the site, the regulations and the products it names, priced at current prices and rated for carbon.
Tested by
H3 Early-design speedHours per facade option and per competition entry; decisions and hours to reach the selected optionTake itVote
Derived deliverablesShare of drawings, schedules and permit checks produced automatically; IDS compliance before drawingsTake itVote
Coordination conflictsConflicts between disciplines found after design freeze, and the cost and time of resolving them, separated into conflicts refused at authoring by ownership of space and conflicts found afterwardsTake itVote
Fees under pressure
The languageA practice writes its design language once, every project inherits it, and others may license it.
Tested by
H3 Early-design speedHours per facade option and per competition entry; decisions and hours to reach the selected optionTake itVote
Company standards as profilesEffort to encode a practice's standards as a profile; compliance of generated options; share of a profile adopted from generalised corrections, and share of those rules later revisedTake itVote
The languageEvery compromise between parties is recorded with what it traded, who decided and why, so that a late cut shows its effect on performance, carbon and design intent before it is accepted.
Reversal costCost of reversing a decision as a function of the commitment state of the elements it affectsTake itVote
Cost of varietyCost and lead-time premium of a unit or bay configured for one project over a repeated configuration of the same systemTake itVote
Authorship with AI
The languageEach element can carry who drafted it, which computations informed it, who confirmed it and against which profile, and the terms on which it may be read, reused or used to train machines.
Tested by
Calculation traceabilityShare of design values traceable to the calculation, rule or standard that set them; time to answer a checking engineer's query; time to identify, for any element, the rule that set it, the rules it overrode and their authorsTake itVote
Epistemic calibrationShare of generated elements whose recorded status, given, fixed, inferred, proposed or confirmed, is correct; details invented where knowledge existedTake itVote
Signature modelsBlind recognition of a practice's style in generated options; acceptance rate of a model trained on its corpus; number of buildings from which a practice profile, inferred as values of the shared heuristics, reaches the same recognition, and the residual it leavesTake itVote
Argued in the manifesto
A large share of every fee is spent redrawing and coordinating information that already exists elsewhere. The language returns those hours to design: as the architect drafts and revises, each option is checked against the brief, the site, the regulations and the products it names, priced at current prices and rated for carbon. A practice writes its design language once, every project inherits it, and others may license it.
Your first step
Test the language on one competition and count the hours.
The languageEvery element is placed on what hosts it and records what carries it, so that the path of support can be read down to the ground and every enclosure can be read to close around the spaces it serves.
Tested by
Analysis models from descriptionsHours to prepare structural, energy and daylight analysis models from a description; discrepancies between the analysis model and the designTake itVote
Engineering rules as profilesEffort to encode a firm's engineering rules, such as spans, deflection limits and service zones, as a profile; share of generated options that pass themTake itVote
Analysis on one option only
The languageWith a shared description, analysis runs on every option from the first sketch, and what the engineer verifies is recorded where every other party can see it.
Tested by
Analysis models from descriptionsHours to prepare structural, energy and daylight analysis models from a description; discrepancies between the analysis model and the designTake itVote
Multicriteria evaluationCriteria evaluated per option and time to evaluate them; functional information of each target; coverage of the Pareto front across domains, by its hypervolume and the extremes it reaches, with and without profiles that each pursue a single objectiveTake itVote
Clashes found late
The languageClashes between trades that federated models now reveal weeks later are refused as they are drawn, and clash detection remains for geometry imported from elsewhere and for the built work.
Tested by
Spatial ownershipShare of interdisciplinary conflicts refused at the edit that creates them, against those found by clash detection on the same project; share of geometry held under ownership; residual clashes by origin: imported geometry, declared unresolved state, deviation of the built workTake itVote
Coordination conflictsConflicts between disciplines found after design freeze, and the cost and time of resolving them, separated into conflicts refused at authoring by ownership of space and conflicts found afterwardsTake itVote
Distributed coordinationRoute length, fittings, ceiling depth consumed and time to convergence for services negotiated among agents over owned space; share of contentions escalated to persons; share of grants later overturned by the responsible engineerTake itVote
Liability for data authored by others
The languageEach change is submitted as a request, checked automatically, reviewed by the owners of every part it affects and merged only when they approve.
Tested by
Calculation traceabilityShare of design values traceable to the calculation, rule or standard that set them; time to answer a checking engineer's query; time to identify, for any element, the rule that set it, the rules it overrode and their authorsTake itVote
Change requests across firmsTime from a change by one consultant to its integration by every affected party; share of changes merged with every check passing; conflicts found after integrationTake itVote
Epistemic calibrationShare of generated elements whose recorded status, given, fixed, inferred, proposed or confirmed, is correct; details invented where knowledge existedTake itVote
Argued in the manifesto
Geometry arrives late and must be rebuilt in each engineering program before analysis can begin. With a shared description, analysis runs on every option from the first sketch, and what the engineer verifies is recorded where every other party can see it. Each discipline, from structure and services to building physics and fire, proposes within the elements and space it owns, and every passage through another's part, a hole in a beam or a break in an insulation layer, is requested from its owner, who grants or refuses it before anything depends on it. These disciplines are examples of an open set: any discipline, including one that does not yet exist, joins by declaring what it owns, the rules on which it grants passage and the checks it requires, without any change to the language. Consultants who are commissioned separately and now exchange files at intervals work instead on one current description: each change is submitted as a request, checked automatically, reviewed by the owners of every part it affects and merged only when they approve, as software teams work through pull requests.
Your first step
Run one analysis directly on the shared description.
Interface independenceSemantic loss when one description is edited in several interfaces; share of constraints preserved by mappings specified as structure-preserving translations, against mappings written by handTake itVote
Specified late or substituted
The languageBecause the language is open to every supplier, suppliers compete within each part while architects compose across all of them.
Marketplace searchTime to find a compliant product for a requirement; manufacturers able to resolve one designTake itVote
Product complianceTime for an authority to verify the declared performance of a product against its mapping and passportTake itVote
Slow manual quoting
The languageThe same description serves as the quotation, the order, the invoice and the record.
Tested by
H4 Design to quoteTime from the architect's design to a priced configuration; configuration errors found at quotation; re-entry hours per facade and per square metre, against the target of section 1Take itVote
Manufacturers maintain product content separately for every program, and their products are often specified late, substituted or reached only through intermediaries. Each product line is mapped once, with its limits, performance, carbon, price and lead time, and quotations follow from the design itself.
Schedules from descriptionsTime to produce a construction sequence and schedule linked to the elements of a description; design changes that reach the schedule without manual updatingTake itVote
Risk priced for what cannot be seen
The languageCost, time and risk are calculated from known parts before anything is built.
Tested by
PredictabilityDeviation of out-turn cost and completion date from the estimate at contract, and its spread across projectsTake itVote
Temporal occupancyConflicts of temporary works, erection sequence and access for maintenance or replacement found on site or in operation, per thousand elementsTake itVote
Derived deliverablesShare of drawings, schedules and permit checks produced automatically; IDS compliance before drawingsTake itVote
Argued in the manifesto
The design is modelled again to quantify, price and sequence it, and what cannot be seen is priced as risk. Quantities, sequences and fabrication data are read from the description, and what was priced as risk is priced as calculation.
Your first step
Take one package from description to fabrication without redrawing.
The languageThe building carries its own record from handover to renovation and finally to the recovery of its materials.
Tested by
As-built recordTime to record deviations on site and to bring the description to the state as built; share of the record that matches the building at handoverTake itVote
Handover completenessShare of the asset information required at handover delivered from the description; days from practical completion to a complete record of assetsTake itVote
Maintenance and warranty found by hand
The languageEvery element records what is known about it, whether given, inferred, proposed or confirmed, and its state over time, from designed and installed to repaired, removed and reused.
Tested by
Maintenance planningTime to produce a maintenance plan with intervals and costs from a description; maintenance planned against maintenance performedTake itVote
Service life and renewalError in the number, timing and cost of the replacements predicted over a study period from the service lives declared in a description, against those recorded in operationTake itVote
Carbon and performance reporting
The languageThe carbon released before a building is used is known from the moment an option is written, and the embodied emissions of a portfolio, a city or a country can be summed from its descriptions.
Tested by
ESG and taxonomy reportingShare of EU Taxonomy and reporting data points for a portfolio populated from descriptions; hours to compile disclosuresTake itVote
Energy certificatesTime to issue an energy performance certificate from a description, and its agreement with a certificate prepared on siteTake itVote
Performance in useGap between the energy use computed from the description and the energy measured in use, and the time to locate its causesTake itVote
Renovation without records
The languageEvery building carries its description from brief to demolition, so that it can be maintained, renovated and finally recovered as a catalogue of its materials.
Tested by
Renovation planningTime to compare renovation options for a portfolio by cost, carbon and energy; share of buildings for which options are producedTake itVote
Existing buildings recoveredTime to recover a description of an existing building from records, surveys and imagery, and its accuracy against a measured surveyTake itVote
Declared recoverabilityShare of the components declared recoverable in a description that are recovered at renovation or demolition, by the evidence on which each declaration restsTake itVote
Argued in the manifesto
Owners and facility managers receive at handover files from which the product, warranty and maintenance of each element must be found by hand. The building carries its own record from handover to renovation and finally to the recovery of its materials.
Your first step
Keep the record of one building live from handover.
The languageEach program implements one engine, a plug-in on its existing interface, so that each product line is mapped once, each tool is integrated once, and every mapping is read by every tool.
Interface independenceSemantic loss when one description is edited in several interfaces; share of constraints preserved by mappings specified as structure-preserving translations, against mappings written by handTake itVote
The languageA suite of programs holds together because its programs share one data model; written in the common language, that data model also reaches every product and every other tool, so that a vendor can rebuild its whole suite on the language and compete on what it builds above it.
Tested by
Market expansionShare of projects receiving design at feasibility; options studied per project; design hours per square metre in adopting firms over timeTake itVote
Interface independenceSemantic loss when one description is edited in several interfaces; share of constraints preserved by mappings specified as structure-preserving translations, against mappings written by handTake itVote
Versions and compatibility
The languageA language held in common keeps its records legible: the first website, written at CERN in the early 1990s, is still open in every current browser.
ReproducibilityIdentical elements and parameters, and geometry agreeing within the stated tolerances, from an identical description across runs and toolsTake itVote
Kernel independenceEqual quantities, adjacencies and identities, within the declared precision class, from the conformance suite on two independent engines built on different geometric kernelsTake itVote
Product content to build
The languageEvery mapped product is readable from the first day.
Tested by
Marketplace searchTime to find a compliant product for a requirement; manufacturers able to resolve one designTake itVote
The languageIncumbents keep their position and gain content they no longer have to build, and newcomers reach every mapped product on their first day.
Tested by
Market expansionShare of projects receiving design at feasibility; options studied per project; design hours per square metre in adopting firms over timeTake itVote
Open disciplinesHours to add a discipline not previously described (its ownership, rules of granting, checked conditions and priority) and have it pass the conformance suite; changes to the core requiredTake itVote
Argued in the manifesto
Vendors build and maintain interfaces to every other program and every product catalogue. Every mapped product is readable from the first day, and a newcomer reaches the whole market with its first release.
The languageAn application carries the derivation of its compliance, which the authority’s own checker verifies, and officials decide what no rule can decide.
Tested by
Automated permit checkingShare of the rules of a building code checked automatically on a submitted description; time from submission to decision; findings later overturned; share of the decision that remains discretionary, and the time officials spend on itTake itVote
Proof-carrying applicationsTime and computation for the authority to verify a submitted derivation, against checking the same design without it; share of findings later overturnedTake itVote
Regulations interpreted differently
The languageRegulations written as profiles apply to every design as it is drafted, and an application is checked against them directly.
Tested by
Codes as profilesEffort to write the rules of a code as a profile; agreement of its results with the decisions of human reviewers on the same submissionsTake itVote
Regulatory readinessShare of the Digital Product Passport fields defined for the product group populated per generated unitTake itVote
No overview of the pipeline
The languageThe housing, carbon and materials of a city’s pipeline are visible while there is still time to act on them.
Tested by
Building stock statisticsTime and cost to compile the floor area, materials and carbon of a building stock from the descriptions held by authoritiesTake itVote
Public consultationShare of residents who review and comment on a proposal shown from its description; time to process their commentsTake itVote
Argued in the manifesto
Regulations are written as text that each party interprets, and applications are checked by reading drawings, which delays permits. Regulations written as profiles apply to every design as it is drafted, an application is checked against them directly, and the housing, carbon and materials of a city's pipeline are visible while there is still time to act on them. An application carries the derivation of its compliance, which the authority's own checker verifies, and officials decide what no rule can decide.
The languageA standard written as a profile is read by every conforming tool on the day of its release.
Tested by
Codes as profilesEffort to write the rules of a code as a profile; agreement of its results with the decisions of human reviewers on the same submissionsTake itVote
Regulatory readinessShare of the Digital Product Passport fields defined for the product group populated per generated unitTake itVote
ReproducibilityIdentical elements and parameters, and geometry agreeing within the stated tolerances, from an identical description across runs and toolsTake itVote
Documents tools cannot read
The languageRequirements must all hold at once, and a contradiction between them is reported to those concerned.
Tested by
Codes as profilesEffort to write the rules of a code as a profile; agreement of its results with the decisions of human reviewers on the same submissionsTake itVote
Interface independenceSemantic loss when one description is edited in several interfaces; share of constraints preserved by mappings specified as structure-preserving translations, against mappings written by handTake itVote
Alignment across standards
The languageIts mapping to IFC and the Data Dictionary keeps existing standards in use.
Language parityDifference in validity, quality and token cost between designs generated from equivalent briefs stated in different natural languages, with generation mediated by the languageTake itVote
Argued in the manifesto
Standards are published as documents and implemented separately in every program, often years later and inconsistently. A standard written as a profile is read by every conforming tool on the day of its release, and its mapping to IFC and the Data Dictionary keeps existing standards in use.
Your first step
Align the language with IFC and the Data Dictionary.
The languageCertification criteria written as profiles are checked as the design develops, and the evidence for a certificate is drawn from the record of the building itself.
Tested by
Energy certificatesTime to issue an energy performance certificate from a description, and its agreement with a certificate prepared on siteTake itVote
Product complianceTime for an authority to verify the declared performance of a product against its mapping and passportTake itVote
Cost of certification
The languageEach design inside a certificate’s range inherits the certified performance, and each design outside it is identified before a product is ordered.
Tested by
ESG and taxonomy reportingShare of EU Taxonomy and reporting data points for a portfolio populated from descriptions; hours to compile disclosuresTake itVote
Energy certificatesTime to issue an energy performance certificate from a description, and its agreement with a certificate prepared on siteTake itVote
Claims checked against what was built
The languageWhere a licensed signature carries responsibility, the record sits beneath it and leaves responsibility where the law has placed it.
Tested by
As-built recordTime to record deviations on site and to bring the description to the state as built; share of the record that matches the building at handoverTake itVote
Performance in useGap between the energy use computed from the description and the energy measured in use, and the time to locate its causesTake itVote
Argued in the manifesto
Evidence for the certification of products and buildings, for performance, safety, carbon or sustainability, is collected after the design is complete and at considerable cost. Certification criteria written as profiles are checked as the design develops, and the evidence for a certificate is drawn from the record of the building itself.
The languageWith a shared description, researchers compare buildings, systems and materials across projects and decades, and publish their findings as rules that every tool applies.
Tested by
Building stock statisticsTime and cost to compile the floor area, materials and carbon of a building stock from the descriptions held by authoritiesTake itVote
ComparabilityAccuracy and effort of counting distinct panel, element and detail typesTake itVote
Measurable productivityA quality-adjusted price index and output per worker computed from the descriptions of completed buildings, and the share of measured cost change attributed to qualityTake itVote
Findings rarely reach practice
The languageFindings are published as rules that every tool applies, each with its sources and revised when use shows it wrong.
Tested by
Feedback latencyTime from a change in demand, price, lead time or capacity to its effect on designs and ordersTake itVote
Profiles that learnOut-of-sample error in the cost, duration and performance predicted for held-out projects by profiles recalibrated through the cascade from measured outcomes, with the profile that set each value recorded and corrections pooled by level; time for the error to return after recalibration, at each level of the cascade; accuracy of counterfactual predictions of cost and performance under alternative profiles, checked on comparable projects that differ in one profileTake itVote
No common benchmark
The languageBecause every building is described in the same terms, the productivity of the industry, disputed today for want of a common unit of output, becomes measurable.
H2 CoverageShare of elements explained by rules versus residual exceptions, with the rule set fixed before the test facades are seen and its length counted, on facades modelled independently of itTake itVote
ReproducibilityIdentical elements and parameters, and geometry agreeing within the stated tolerances, from an identical description across runs and toolsTake itVote
Argued in the manifesto
Studies of construction depend on data that is scarce, private and described differently in every source, and their findings rarely reach practice. With a shared description, researchers compare buildings, systems and materials across projects and decades, and publish their findings as rules that every tool applies.
Your first step
Take up a hypothesis of the whitepaper, or propose your own.
The languageTeaching in a common language joins the principles of construction to the tools in which they are applied.
Tested by
LiteracyHours for students to read and write a description at each level of the literacy scale; options they explore in a studio; design competence retained by students who write descriptions themselves, compared with students who select among generated optionsTake itVote
Interface independenceSemantic loss when one description is edited in several interfaces; share of constraints preserved by mappings specified as structure-preserving translations, against mappings written by handTake itVote
Coordination learned only in practice
The languageA student composes a building and sees its cost, carbon and performance from the first studio.
Tested by
LiteracyHours for students to read and write a description at each level of the literacy scale; options they explore in a studio; design competence retained by students who write descriptions themselves, compared with students who select among generated optionsTake itVote
The languageEach party sets and checks its machines against its own profile, through an interface built for its own trade that requires no code.
Tested by
LiteracyHours for students to read and write a description at each level of the literacy scale; options they explore in a studio; design competence retained by students who write descriptions themselves, compared with students who select among generated optionsTake itVote
Students learn programs that change every few years and meet the coordination of practice only after graduation. Teaching in a common language joins the principles of construction to the tools in which they are applied, so that a student composes a building and sees its cost, carbon and performance from the first studio.
The languageEach element can carry who drafted it, which computations informed it and who confirmed it, and against which profile.
Tested by
Calculation traceabilityShare of design values traceable to the calculation, rule or standard that set them; time to answer a checking engineer's query; time to identify, for any element, the rule that set it, the rules it overrode and their authorsTake itVote
Epistemic calibrationShare of generated elements whose recorded status, given, fixed, inferred, proposed or confirmed, is correct; details invented where knowledge existedTake itVote
On what terms work teaches the next model
The languageEach element can carry the terms on which it may be read, reused or used to train machines.
Tested by
Signature modelsBlind recognition of a practice's style in generated options; acceptance rate of a model trained on its corpus; number of buildings from which a practice profile, inferred as values of the shared heuristics, reaches the same recognition, and the residual it leavesTake itVote
Company standards as profilesEffort to encode a practice's standards as a profile; compliance of generated options; share of a profile adopted from generalised corrections, and share of those rules later revisedTake itVote
Who answers when it fails
The languageWhere a licensed signature carries responsibility, the record sits beneath it and leaves responsibility where the law has placed it.
Tested by
Calculation traceabilityShare of design values traceable to the calculation, rule or standard that set them; time to answer a checking engineer's query; time to identify, for any element, the rule that set it, the rules it overrode and their authorsTake itVote
H5 Validity by constructionShare of outputs valid against schema and system rules, and share accepted by the manufacturer's own configurator; position of the first invalid junction in a generated cascade, and number of dependent elements it affectsTake itVote
Your first step
Write as profiles the principles on which your members’ work is authored and reused with machines.
The roles and problems chosen here, and how long each part is read, are recorded without cookies or personal data to rank the challenges; the role chosen is remembered in this browser.
Lineage
Nearly every part has a precedent. The combination is new.
Architects have described buildings by modules, orders, types, patterns, grammars and models for two thousand years. The foundations review eleven strands of that work, from Vitruvius to the language models of 2026, trace each to the fields from which its concepts came, and find a precedent for nearly every component of the Common Building Language (CBL); what remains its own is their combination. The language and Cascading Style Profiles (CSP) are defined together. What multiplies afterwards is the heuristics that every party writes in them, from the regulator to the project, each level multiplying the combinations one description admits.
The eleven strands of the foundations, each drawn firm from its first milestone to its last, on a time scale compressed toward the present; point to a milestone for its work and date. With two sets of heuristics at each of six levels, one description admits 64 combinations, and each further level doubles them.
The web already works this way, brilliantly, on billions of pages and in any browser.
Every page on the web is written in HTML, which says what is on the page, and styled with CSS, which says how it looks. Both are open and kept apart: every browser implements the same two standards, and one style sheet can change the look of a whole site without touching its pages. The Common Building Language (CBL) and Cascading Style Profiles (CSP) bring the same arrangement to buildings.
The webA building
What is thereHTML<h1>Pavilion</h1>What is on the page: a heading, a paragraph, a picture.CBLroof · rests on the columnsWhat is in the building: each element, where it is and what it relates to.
How it looksCSSh1 { font-family: serif; }Fonts, colours and layout, set apart from the page.CSPcolumn: steel, I-sectionThe selection of each party, from regulation to project, set apart from the description.
Who reads itAny browseron any deviceBillions of pages, each written once.Any toolin any officeEvery building, each described once.
This site carries a second style of its own. The switch Aa at the top sets every page in it, with other faces and colours and every size and space kept, as a style sheet changes a site without touching its pages.
See style changes here
1234
In the Common Building Language (CBL) each element is named by its type and related to the others: the terrace hosts the hall and the columns, the columns carry the roof, the hall encloses 2,540 m². The requirements descend to each element. The drawing sets the elements on the grid only to show them; nothing yet says what form they take or how they are made.
In Cascading Style Profiles (CSP) each party writes its selection within the language. A practice profile selects an orthogonal order, steel sections, a deep roof grid and glass between vertical mullions; the project profile, more specific, sets the granite of the terrace.
A profile may govern form as well as material. Another practice profile sets the hall on a rounded plan with its walls leaning outward, tapers and inclines the columns, and bends the roof into one shell. Every relation of the description holds: the roof rests on the same eight columns, and the hall encloses the same area under it.
A third practice profile makes the roof of curved sheets that meet at folds, sets the hall in inclined facets and leans each column its own way. The description and the project profile are unchanged, so the same building takes a third form.
terrace · surface · grid 3.6 m · hosts the hall and the columns
granite, jointed on the gridprojectgranite, jointed on the gridprojectgranite, jointed on the gridproject
2Hall
enclosure · 4 surfaces · 2,540 m² · transparent
glass in steel frames on a square plan, vertical mullions every 3.6 m, one transompracticeglass on a rounded plan, walls leaning outward, mullions following the curvepracticeglass in inclined planar facets, in horizontal bandspractice
3Columns
column × 8 · carry the roof
steel, I-section, verticalpracticewhite concrete, tapered, inclined toward the edge of the roofpracticesteel tubes, each at its own inclinationpractice
4Roof
roof · surface · covers the hall · rests on the columns
steel grid, 1.8 m deep, dark fasciapracticewhite shell, doubly curved, 0.4 mpracticecurved metal sheets meeting at folds, 0.7 mpractice
Models and tools
Every model can write it. Every tool can read it.
Language models already generate scripts, drawings and models of buildings, each in the format of one tool, and each answer starts again from nothing. The same models can write in the Common Building Language (CBL): what they write is checked as it is written, expands to the same building in every tool, and can be edited, merged and priced by every party. Each difference below is tested by a hypothesis of the whitepaper.
A model on its ownThe same model writing CBLTested as
TranslationEvery tool and every model needs a translation to every other, so the work grows with the product of their numbers.Every tool, model and product line maps once to one language, so the work grows with their sum.H6
CollaborationA generated model is a file, replaced whole at each round, and the changes of two parties cannot be merged.A description is text, versioned and merged element by element, as code is.Collaboration and versioning, Interface independence
CustomisationA practice's standards and style are restated in each prompt, differently by each person.Standards and style are written once as profiles and applied by every tool and every model.Company standards as profiles, Signature models
Size and costGeometry and exchange files are long, and a model pays for every token it reads and writes.A description states the decisions and derives the geometry by expansion; its length in bytes and tokens is measured against IFC.H1
ValidityOutput can break the rules of the products it names, and the errors are found after it is written.Output is checked against the schema and the manufacturers' rules as it is written.Reliability, H5
Each jointA model gets the overall design largely right and single joints wrong, and one wrong joint passes into everything built on it.Each joint is checked against the rules that govern it before anything depends on it.H5
ReproducibilityThe same request gives a different building on each run.The same description expands to the same elements in every tool and on every run.Reproducibility
KnowledgeInvented details look the same as known ones.Every element records whether it was given, fixed, inferred, proposed or confirmed.Epistemic calibration
InspectionNo one can see which rule produced an element.Every element shows the rules that shaped it, the rule that prevailed and who wrote it.Calculation traceability
ProductsProducts are known as they were in the training data, without current price or lead time.Mapped products carry their limits, price, lead time and carbon at the moment of design.Supply-aware design, Marketplace search
Your tools stay. Revit, Archicad, Rhino, Grasshopper and the fabricators' software each implement one expansion engine or one mapping and from then on read and write the same description, and IFC and drawings are produced from it, so the language can be adopted one project at a time. Free software lowers the cost of tools. A common language lowers the hours lost between them.
The manifesto
Ten statements. Read them, then sign.
The manifesto sets out ten statements, each with the belief it rests on, in about twenty-five minutes of reading. The signature follows the last of them, so that every name below stands under the text it supports.
Every signature is welcome, and each one widens the community in which the language can be adopted. A signature records agreement with the manifesto; an improvement is shown only by measuring the work of a domain with and without the language. The whitepaper states such claims as hypotheses, each with its measure and the baseline it must beat: six chosen as first tests, and one hundred suggested as open challenges that any organisation may take up, modify or replace. Every organisation that has signed is invited to take one up on a real project, and a hypothesis receives its number when it is taken up.
A challenge taken up carries a responsibility. The pioneer records its own baseline before the work begins, repeats the work with the language, and publishes both results with the project, whatever they show. The list shows who is at work on each challenge, so that organisations on the same one can join their efforts, and every result once it is published. Organisations that complete a pilot and publish its measures are invited to become founding members of the neutral body that will steward the language, with seats balanced across the domains.
Of the 106 challenges, 6 are chosen as first tests and 100 are suggestions, open to take up, modify or replace. Until the first pilots begin, the list shows the six first tests.
Every pioneer, advocate and supporter is placed at the city they gave, or else in their country, with a line from each signatory to the signatory whose invitation brought them. Choose a domain and a country to find the advocates there; everyone who has taken part is listed below the map.
