How the engine works

Context packages

A context package is versioned reference data attached to a revision: a regulation (what an authority publishes, with its conditions), a style, what a supplier sells, or a manufacturer's own published document, one package per document, quoted beside the answer with its URL and the day it was read. Each names its publisher and status; source-based packages also carry links, jurisdiction and the date sources were read. Published versions have immutable content digests. Runs retain the exact package snapshots they read. Some older version labels predate this publication record; their saved run evidence is the reference for what was used. Nordform publishes the shared packages, and a company administrator publishes the company’s own packs to its members.

Families and kits

A family is what is being designed: a house envelope, a deck, a portal frame, a folded enclosure. It owns its inputs, geometry kernel, permitted checks and exports, review scope and sources. A kit is the construction system that realises it, written as parameters, limits and rules, for example a 600 mm timber module or a plywood cassette grid. The house family has two kits: the timber-frame concept and the WikiHouse Skylark 150.

Each kit records how its parts are obtained (merchant materials, openly licensed files, a company’s product sold in named countries, or nothing anyone may build from), and that decides whether it is offered. A manufacturer’s product is not listed outside the countries it is sold in, and the design records what was left off and why.

Each kit publishes an execution contract: its kernel, required checks, exports and default context. Contracts are versioned and immutable. A revision binds to one contract version, and retries and new generations from it use that version; adopting a newer contract needs a new revision.

Independent rectangular building concepts are separate from kit execution. A typed proposal produces deterministic concept geometry; family-fit findings are advisory and do not change the requested shape. The kit checks below and kit production files belong to kit designs. Their backup retains the actual concept inputs.

Bounds

Deterministic

Saved inputs against a stated numeric limit, such as a width, a pitch or a clear distance.

• Pass
• Fail
• Not assessed

e.g. parameter-bounds@1

Integrity

Deterministic

The generated model against itself: every member distinct, finite and positive. If it fails, no package is made.

• Pass
• Fail
• Not assessed

e.g. frame-integrity@1

Prescriptive

Deterministic

A published rule with its conditions, from a context package pinned to the revision. Outside the rule’s scope the result is out of envelope.

• Pass
• Fail
• Out of envelope
• Input required
• Not assessed

e.g. room-area@1

Engineering

Deterministic

A validated solver, inside the envelope it was validated on, which the result states. Outside it the check refuses and names the gap.

• Pass
• Fail
• Refused
• Input required
• Not assessed

e.g. bearing-resistance@1

Applicability

Non-deterministic

Which rules may govern the project. The type has no pass state.

• Candidate
• Unresolved
• Input required
• Not assessed

e.g. regulatory-applicability@1

Narrative

Non-deterministic

Explanation attached to a result. It has no state, so nothing downstream can read it as an outcome.

• No state

No result of this class is emitted today.

A check’s class limits which states it may emit. The type system enforces this: a non-deterministic check has no pass state, and a result that claims one is rejected in the database, the API and the MCP server.

Result states

Pass

Bounds, integrity, prescriptive, engineering

A deterministic check ran inside its envelope and the condition holds. The only green state.

Fail

Bounds, integrity, prescriptive, engineering

The condition does not hold. The only state that stops a package.

Out of envelope

Prescriptive

The published rule does not cover this case. Nothing is generated or inferred.

Refused

Engineering

The solver is not validated for this case. The result names the gap.

Input required

Prescriptive, engineering, applicability

A value the check needs is missing from the revision.

Not assessed

Every class

The check did not run, for example a stair check on a single storey.

Candidate

Applicability

A rule that may apply, with its source and date, for a person to confirm.

Unresolved

Applicability

The sources do not settle the question.

Stale

Any result

A context package the result read has a newer version. The result is marked stale.

Each result records the kit version, context package snapshots, the implementation that evaluated it and a hash of its inputs. New timber runs also retain adopted ground inputs, site loads and the product records used by their checks. Older records retain their original evidence format.

Approval of a design comes from expert opinion, manufacturing release and an authority decision, each a separate step. A workflow is qualified for a family and jurisdiction only when a fixture set with independently verified results exists and a named professional there has accepted the check definitions. Until then its checks run advisory.

Checks by registered identifier. “Live” runs on the site today.

House envelope

Check	Class	What it reads	Status
parameter-bounds@1	Bounds	Width 3–10 m, length 3–16 m, wall height 2.2–4 m, roof pitch 10–45°. Runs in a pinned container that treats the parameters as data. Mandatory in every house contract.	Live
frame-integrity@1	Integrity	Every frame member has a distinct identity, a finite positive length and a positive section. On failure the run fails and no package is made.	Live
Opening rules	Bounds, on save	Openings 0.4–2.4 m wide and high, 300 mm clear of wall ends, the wall head and neighbouring openings; door sill zero, window sill at least 300 mm; an upper-storey opening needs two storeys. A revision breaking these cannot be saved.	Live
storey-room-height@1	Prescriptive	Clear height on every storey at least 2.4 m, decree 1008/2017 § 4, before ceilings, insulation and finishes.	Live
storey-stair@1	Prescriptive	Straight stair between storeys: risers at most 190 mm, going at least 250 mm, 900 mm flight, 1950 mm headroom and the floor opening, decree 1007/2017 §§ 3, 4, 14, with flight and landing inside the envelope. Input required until a stair is placed; not assessed on one storey. Handrails, winders, balustrades and fire separation are not read.	Live
bearing-resistance@1	Engineering	Drained bearing resistance of a centrally loaded rectangular spread footing, EN 1997-1 Annex D, with the Annex A partial factors for the named Design Approach; reports design pressure, design resistance and utilisation. Runs only when the Eurocode 7 package is selected and the run carries a footing and ground model naming who derived the parameters and when; without one it says not assessed. Eccentric, inclined, submerged and undrained cases are refused. The national annex is not verified. Not a geotechnical assessment.	Live

The calculation reproduces the Bond and Harris worked example (pad on dry sand) across DA1-1, DA1-2, DA2 and DA3.

Skylark 150 kit

Check	Class	What it reads	Status
skylark-module-fit@1	Integrity	Wall modules compose on the kit’s pinned grid for the saved inputs: block counts and cutting sheets, from source geometry held by commit hash. No structural conclusion.	Live
skylark-production-readiness@1	Engineering	Floor and roof assembly, gable bearing, joints and fixings. Always not assessed: the kit’s interface assumptions are unconfirmed.	Live

Lammi block wall

Check	Class	What it reads	Status
lammi-block-module-fit@1	Integrity	Envelope and openings on the manufacturer’s 200 mm module, wall height in whole 200 mm courses, each opening within the guide’s lintel span with bearing beyond its jambs; then block, concrete and mass counts. No structural conclusion.	Live
lammi-block-engineering@1	Engineering	Reinforcement, lintel courses, wall load-bearing, slab and foundation. Always not assessed: the guide’s tables need wall loads this design does not carry, and the manufacturer’s structural designer sizes them.	Live

Figures come from Lammi’s public product pages and the design guide for the chosen wall block (thermal blocks or formwork blocks), read on a stated date, with no rights recorded. The count is an estimate to compare with the manufacturer’s take-off.

RunkoPES 2.0

Check	Class	What it reads	Status
runkopes-envelope-fit@1	Integrity	Envelope within the chosen frame system’s published dimensions: floor depth for the span, storey and room height, opening clear width and lintel deflection allowance, and the manufacturing tolerance class set by the storey count. No structural conclusion.	Live
runkopes-structure-library@1	Engineering	Structure types and their fire, acoustic and thermal requirements. Always not assessed: the library states requirements, the element supplier chooses products and obtains acoustic approvals, and the figures predate the 2018 Finnish fire decree.	Live

RunkoPES is an open Finnish timber building system. It fixes module lines, storey height, floor thickness per span, opening width and element tolerance, and no element length, so the run reserves space and counts nothing. All three frame systems are included: load-bearing large panel elements (the default for a new house project), post-and-beam, and volumetric. Figures were read from the thirteen public part documents on a stated date, with no rights recorded, and the structure type library is written for P2 fire class apartment buildings of three to eight storeys.

Rooms

A room is a zone on a storey plan with a use and an area, drawn as a rectangle or an orthogonal outline. Its area is the outline’s, net of any stair opening it is drawn over. Rooms do not split the geometry.

room-egress@1 reads only whether openings connect. It is not a fire-safety assessment: escape time, number of exits, secondary routes, exit dimensions, escape doors, non-habitable rooms, circulation width and finishes are not read.

Check	Class	What it reads	Status
room-area@1	Prescriptive	Every habitable room at least 7 m², decree 1008/2017 § 4, between zero-thickness partitions, net of stair openings.	Live
room-clear-height@1	Prescriptive	Habitable rooms and kitchens 2.4 m clear, same decree, before ceilings and finishes.	Live
room-daylight@1	Prescriptive	Window light opening at least a tenth of the floor area of a habitable room or kitchen, decree 1008/2017 § 5. The whole rough opening is counted, which overstates it.	Live
room-egress@1	Prescriptive	Whether the doors in the model connect every habitable room to the outside: internal doors of a wall-aware layout, across storeys and down the stair, to a ground-floor room with an exterior door. A door in an upper wall is never counted as a way out, and a sealed room fails. Where the model cannot tell (no layout, no ground-floor exterior door, a stair end on floor no room covers) the result is not assessed with the reason.	Live

Site and plot

These read an index map and site facts adopted from an authority document, not a boundary survey.

Check	Class	What it reads	Status
site-boundary-setback@1	Prescriptive	Footprint inside the cadastral parcel and at least the recorded distance from its boundary: by default 4 m in Finland, a common figure, and 2.5 m in Denmark, the building-regulation default for a detached house. The local plan decides. Input required until a parcel outline exists.	Live
plot-building-separation@1	Prescriptive	Other buildings on the plot at least the recorded separation away, 8 m by default from decree 848/2017, with no overlapping footprints. Not assessed when the design is alone on its plot.	Live
site-building-rights@1	Prescriptive	Footprints against the building rights or efficiency ratio adopted from the zoning document. Footprint is a lower bound; statutory floor area is not computed.	Live
site-ground-snow-load@1	Prescriptive	Ground snow load adopted from Figure 4.1 of the Finnish national annex to EN 1991-1-3, minimum 0.5 kN/m². The map is not embedded: without an adopted value, input required. Out of envelope outside Finland.	Live
site-wind-basic-velocity@1	Applicability	Candidate basic wind velocity from the Finnish national annex to EN 1991-1-4: 21 m/s mainland, 22 m/s open sea and outer islands, 26 m/s Lapland fell tops. Terrain category, orography and annex edition are for the engineer.	Live

When the design pins a data-centre package, six screening findings join the list. They are applicability results, so the most any of them says is candidate; none passes or fails a plot.

Check	Class	What it reads	Status
datacentre-plot@1	Applicability	Plot area, perimeter and the smallest rectangle around the cadastral outline, with the share of it the plot fills.	Live
datacentre-terrain@1	Applicability	Relief and slope over the parcel from the 2 m elevation model the ground screening read. No cut/fill volume. Input required until the ground is screened.	Live
datacentre-grid@1	Applicability	What the pinned Finnish grid-connection package says about large demand connections. Distance to the grid is stated as unknown: no substation or line map is read.	Live
datacentre-permits@1	Applicability	Registration and permit thresholds for standby power, fuel and water from the pinned Finnish permits package. Whether the plot is in a groundwater area is not read.	Live
datacentre-climate@1	Applicability	Eurostat cooling degree days at the country's reference place, as a proxy for the free-cooling season. Free-cooling hours are not computed.	Live
datacentre-seismic@1	Applicability	ESHM20 reference-rock acceleration at the capital against the 0.04 g very-low-seismicity value of EN 1998-1. Not a design ground acceleration.	Live

Other families

Every family other than the house is illustrative: it runs through the same engine and describes nothing anyone may build from. The steel portal frame exports IFC 4.3 member bodies with illustrative placeholder sections and stable element ids. Optional door jambs and a head member are included in its geometry and exports. Its planner receives deterministic clash findings and, where the bounded bracing move clears them, a rechecked candidate.

Steel cloud orchestration and engineering sizing remain incomplete. Since 11 September 2026 decks, outbuildings, garden structures, exhibition stands and joinery also draw a preliminary layout; every spacing and proportion in it is an assumption, named on the drawing, in the schedules and in the checks. Nothing is sized. Those families, with decks, raised decks and the framed opening, stay in the registry and open from a direct link; the catalogue and the workspace's choosers no longer list them.

Family	Checks	What they read
Steel portal frames	portal-layout-integrity@1, portal-door-reservation@1 (integrity); portal-frame-strength@1, portal-member-sizing@1 (engineering)	Frames, bays, member roles and total steel length for a symmetrical single-span frame of 6–60 m, and one side-wall door against the bracing, columns and optional head member; a clash names the affected members. Optional jambs and a head member are geometry, not sized construction details. On the recommended-factor basis, frame strength waits until you state a steel grade and a snow load; for buildings with at least two bays, it then analyses one interior frame in its own plane in the EN 10365 column and rafter sections you choose, and passes or fails a simplified member check that runs advisory, and grants no engineering approval. It names the governing member and combination, and, where found, a heavier section that brings the affected member group under its limit; this can be sent to the design as a request. Requesting a Finnish or Swedish national annex leaves strength at input required, naming the unconfirmed national factors and the reviewed calculation method still needed. No national annex is applied. Frame self-weight is derived, but site snow and wind pressures must be supplied. Lateral-torsional buckling, second-order effects, haunch structural resistance and connections are not checked. Sizing, connections, bases and stability: always not assessed.
Fabric-covered halls	fabric-hall-layout-integrity@1, fabric-hall-delta@1, cover-strip-layout@1, cover-roll-plan@1 (integrity); cover-compensation@1, fabric-hall-frame-strength@1, fabric-hall-structure@1 (engineering)	A hall of arch frames as a list of pieces, and against a hall that already stands, which pieces stay, move, are new or come out. The cover developed flat, split into strips no wider than the roll and laid along rolls, the same way for the same inputs. Part codes are placeholders, and frame spacing, weld overlap, edge allowance and roll size are your inputs: no maker’s catalogue or cover rules were read. Compensation is applied only as you enter it. Frame strength waits until you state the chord and lacing tubes, the steel’s yield strength and a snow load; it then analyses one interior frame in its own plane and passes or fails a simplified member check that runs advisory, which no engineer has accepted and which approves nothing. Purlins, wall rails, gable posts and bracing are checked the same advisory way once you state their tubes, each as a simple member on its own; that check can fail and never passes, because gable frames, bases, connections, the fabric and the hall in three dimensions are always not assessed. Where a check fails it says which tube size would pass, and that can be sent to the design as a request.
Wind turbines	wind-turbine-layout-integrity@1 (integrity); wind-turbine-foundation-eccentricity@1, wind-turbine-foundation-bearing@1, wind-turbine-foundation-sliding@1, wind-turbine-structural-design@1 (engineering)	A published 3.4 MW reference tower (IEA Wind Task 37, Apache-2.0) stretched to your hub height, with its plain steel mass, on a circular or octagonal gravity foundation of your size. The three foundation checks wait until you give the overturning moment and thrust at the tower base; they then screen lift-off against the kern, bearing on the effective area against EN 1997-1 Annex D and sliding, with recommended Design Approach 2 factors, zero cohesion and deep groundwater. A screening, not a foundation design. Fatigue, buckling, flanges and bolts, natural frequency, turbine load cases and the concrete: always not assessed.
Welded skid frames	skid-layout-integrity@1, skid-equipment-fit@1, skid-lift-balance@1 (integrity); skid-frame-strength@1, skid-structure@1 (engineering)	Two runners and cross members under one piece of equipment, with a cut list, the mass and the centre of gravity in plan. The equipment must sit inside the frame with its mounting points on a member and its lifting points clear by 100 mm; the four lifting points share the weight by the lever rule, and none may carry more than 37.5 %. The section is assumed from the depth you enter, and the 100 mm and 37.5 % are our own guesses, not a lifting standard. Strength waits until you state a steel grade; it then checks the runners and cross members, set down on the runner ends, in the channel or tube sections you choose, carrying the equipment, with the same advisory member check as the portal and the same findings on a fail. The lift, welds, lifting lugs and slings: always not assessed.
Access platforms	access-platform-layout-integrity@1 (integrity); access-guarding@1, access-clear-width@1, access-stair@1, access-headroom@1, access-ladder@1 (prescriptive); access-platform-strength@1, access-platform-structure@1 (engineering)	A platform on posts with its guard-rail, reached by a straight stair or a caged ladder, measured against illustrative EN ISO 14122 values, each cited where it was read; meeting them is not a conformity statement. Strength waits until you state a steel grade and an imposed load; it then checks the posts and edge beams as one frame in the EN 10219 tubes you choose, with the same advisory member check as the portal and the same findings on a fail. Connections, bracing, the stair, the guard-rail and the foundations: always not assessed.

| Foundations | foundation-layout-integrity@1 (integrity); foundation-frost-depth@1 (prescriptive); foundation-bearing@1, foundation-sliding@1, foundation-overturning@1 (engineering) | Pad footings, one strip footing or a pad grid under columns: outlines at an assumed thickness, concrete volume, and the base against a published frost depth for southern or northern Finland. Bearing reuses the EN 1997-1 Annex D calculation; sliding and the middle-third eccentricity are characteristic, with no partial factor. Each ground check asks for the soil friction angle or the horizontal reaction until they are entered. Not reinforced, not a site design. | | Sheet-metal enclosures | blank-development@1 (integrity); tooling-and-springback@1 (engineering) | The flat blank developed from the four folded faces with the open bend-allowance formula and your K-factor. Tooling, minimum flange, bend relief and springback: always not assessed. | | Duct runs | duct-run-layout-integrity@1, duct-run-connectivity@1 (integrity); duct-run-velocity@1, duct-run-supports@1 (bounds); duct-run-design@1, duct-run-support-strength@1 (engineering) | One ventilation duct, round or rectangular, of one or two legs and one branch. Each part is sized for its air flow at a friction loss you set, by the Colebrook equation and, for a rectangle, Huebscher’s equivalent diameter, then rounded up to a common size. Velocity is compared with the upper end of published ranges for the building’s use. The pressure loss to each end adds straight friction to fitting losses that are pipe-fitting coefficients standing in for duct fittings. The connections are read back from the ports. Hangers are placed at a published spacing for the duct's cross-section and loaded with its sheet steel on an assumed gauge, and the hanger bearer and rods are sized the same way as a pipe run's. Fan, noise, leakage, fire, balancing and hanger fixings: always not assessed. | | Electrical circuits | final-circuits-layout-integrity@1, final-circuits-connectivity@1, service-openings@1 (integrity); final-circuits-protection-and-sizing@1 (engineering) | One board and up to three radial final circuits of sockets, luminaires or a fixed appliance, each cable on an assumed route up to the ceiling, along it and down. The connections are read back from the terminals alone — they meet, on the same circuit, with the same cores — and every point must be reachable from the board. No wiring standard was read, so nothing is a rule. The openings the cables need through a ceiling structure are listed against an assumed structure or against another design in your account read at one version, the same way as for a pipe run, and none is accepted here. Conductor sizing, protective devices, earthing, voltage drop and fault loop: always not assessed. | | Cable routes | cable-route-layout-integrity@1, cable-route-connectivity@1 (integrity); cable-route-tray-fill@1, cable-route-supports@1 (bounds); cable-route-rating@1, cable-route-support-strength@1 (engineering) | One run of cable ladder or perforated tray of one or two legs and one branch, with up to 60 cables of one type from pandapower’s standard cable types. The fill compares the cables’ cross-section with the tray’s against a 40 % planning figure that is ours; tray side heights, bend radius and cable diameters are assumed. A rough grouping screen reduces the published rated current by 1/√n; it is not a table value. The connections are read back from the ports. Supports are placed at the spacing you enter and loaded with the tray and cables, weighed from assumed dimensions, and the bearer and rods are sized the same way as a pipe run's. Cable rating, voltage drop, fault withstand and support fixings: always not assessed. | | Cable tray fill | cable-tray-fill-attachment@1, cable-tray-fill-routed@1 (integrity); cable-tray-fill-capacity@1 (bounds); cable-tray-fill-rating@1 (engineering) | A ring of cable tray around a hall with cross trays between its long sides, one board and up to 40 loads, and one cable per load routed through the trays. Each tray part offers one layer of a stated share of its width; the next cable is drawn towards the trays with room, accepted on its true length, and a bounded pass reroutes what shortens the total. Every tray part's fill is reported, and a cable the width cannot hold is reported as not routed. Tray widths and heights are inputs, cable diameters are assumed, attachments are not checked against anything, and the global optimum is not claimed. Rating, grouping, segregation, bend radius and supports: always not assessed. |

| Pipe runs | pipe-run-layout-integrity@1, pipe-run-connectivity@1, service-openings@1 (integrity); pipe-run-supports@1 (bounds); pipe-run-ped-category@1 (prescriptive); pipe-run-pressure-drop@1, pipe-run-pressure-design@1, pipe-run-support-strength@1 (engineering) | One piping branch of up to three legs: pipes, right-angle elbows, one tee and flanged or plain ends, each reduced to its ports. The connections are read back from the ports alone — they meet, they face each other, their radii agree — so an end that meets nothing is reported. Outside diameters are the published ones and the bore comes from a chosen schedule (40, 80 or 10S); elbow, tee and flange dimensions are cited ASME B16.9 and EN 1092-1 PN 16 values, illustrative. At a stated water flow the run's pressure drop is estimated (Darcy–Weisbach, Colebrook, Darby 3-K) and the velocity held to an illustrative 3 m/s. Supports are placed along the run — trapezes on level legs, brackets on risers — at the support spacing a published hanger table gives for steel pipe in water service, and each is loaded with the pipe full of water; the check reads the distance between neighbouring supports back along the centreline. Sizes the table was not read for get no supports. Once you state the support steel grade, the trapeze bearer and rods are sized by a frame analysis of the heaviest support, the lightest square hollow section and threaded rod on a short list that hold it under a simplified member check. The openings the run needs through a structure are listed with the member, the position and the size, against an assumed zone you choose or against another design in your account (a steel portal, a house) read at one of its versions; when that design gets a newer version, the run is made again against it with its own inputs unchanged and the checks that changed are shown, and the reading moves to the newer version only when you adopt it. Each opening is set against one cited rule of thumb and none is accepted here. Pressure design, rating, support fixings and stress: always not assessed. With a stated fluid group and maximum allowable pressure, the run states its Pressure Equipment Directive category from Annex II Tables 6 to 9, read from the directive’s own charts; that is a category, not a conformity assessment, and the line is still not pressure designed. | | Power-to-methane plants | p2m-tag-series@1, p2m-flue-gas@1, p2m-hydrogen-bank@1, p2m-supply-share@1, p2m-accuracy@1, p2m-buffer-volume@1, p2m-seveso-hydrogen@1, p2m-reproduce-balance-and-cost@1, p2m-reproduce-quantities@1, p2m-pid-system-codes@1, p2m-pid-cross-sheet@1, p2m-pid-interlocks@1, p2m-pid-coverage@1, p2m-site-safety@1, p2m-downstream-fit@1, p2m-revision-diff@1, p2m-steel-model@1, p2m-tray-register@1, p2m-tray-separation@1, p2m-fire-separation@1, p2m-fire-escape@1, p2m-fire-resistance@1, p2m-chemical-thresholds@1, p2m-atex-electrical@1, p2m-hall-ventilation@1 (integrity); p2m-design-basis@1 (engineering) | A pre-design of an e-methane plant reproduced from an industrial specialist’s own report, workbook and 3D layout: the mass and energy balance, investment, production cost and return calculation follow from their stated assumptions, and their site is measured again for a priced takeoff of eight local contract packages. Choosing fewer modules or CO2 from biogas takes the parts out of their layout; eleven to twenty modules add a second hall on a plot extended 90 m east, which is our proposal, and enlarge the units after electrolysis in place, with a check of where they stop fitting. Their eight P&ID sheets are read into a register of equipment, RDS-PP designations, instruments, interlocks and Ex zones; that reading was made from images and lists every doubtful character, so its checks are of kinds a misread digit cannot cause. The audit compares their documents with each other and with what their own assumptions give, so a figure left behind from an earlier revision is found. Pre-design accuracy, ±30–40 %. The site is screened against published siting rules (hydrogen and chemical store distances to the boundary, emergency shower reach, Seveso thresholds, pipe bridge clearance) on distances measured as drawn, and the P&IDs’ Ex zones are drawn with an indicative margin. The specialist’s later revision adds the steel frames of eight buildings as a member model, cable trays in five systems, doors, windows and hatches, and a fire, explosion and chemical check: the kernel adds the members up against the report’s tonnage per building and tests them against the equipment and pipes as drawn, adds the trays up against the report’s lengths per system and tests every pair of different systems within 3 m against the specialist’s own separation matrix, and measures building separation, escape distance, the frame’s fire resistance, the hydrogen inventory against the chemical decree’s tiers, electrical units against the declared Ex zones and the hall’s ventilation rate; what changed between the two revisions is a finding of its own. The frames are measured, never sized: their sections are the specialist’s, from a frame calculation the report itself calls an AI-assisted check. Vendor data, hazard study, area classification, release modelling and permits: always not assessed. | | Process plants | process-plant-topology@1, process-plant-pid@1, process-plant-tagging@1, process-plant-layout@1, process-plant-piping@1, eight process-plant-boiler-…@1, process-plant-pcf-roundtrip@1, process-plant-pcf-continuity@1 (integrity); process-plant-design-basis@1 (engineering) | The water–steam side of a steam plant from a brief: a process graph, a P&ID drawn by our own patterns and found again by a separate check, KKS tags from one Finnish power-plant project’s coding guide as transcribed, equipment placed in a row, and pipe routed on a lattice, with a Piping Component File and an isometric per line. The worked example’s files are opened by an independent PCF reader in the repository’s tests. The eight boiler rules are one engineer’s note; where the model has no word for what a rule needs, the rule says so and is not assessed, and a warning is never a pass. At a stated steam flow it adds textbook estimates on named assumptions — feedwater pump hydraulic power, drum shell and head wall, and on the closed loop the heat consumer's duty and area — which are not sizing. Heat and mass balance, sizing, set pressures, stress, supports and hazard study: always not assessed. An I/O list is read from the P&ID (transmitters as analogue inputs, switches as digital inputs, loop control valves as analogue outputs, every other valve taken as manual), and the equipment, line, valve, instrument and I/O lists come as one workbook with the tag register; no cabinet, card, channel or cable is assigned. | | Data halls | data-hall-layout-integrity@1, data-hall-unit-clearances@1, data-hall-service-clashes@1 (integrity); data-hall-fire-compartment@1, data-hall-suppression-zone@1 (prescriptive); data-hall-floor-load@1, data-hall-cooling-floor-escape@1 (engineering) | Rack rows with cold and hot aisles and a gallery of cooling units along one end wall, counted from the hall’s size, the rack load and the aisle widths you enter. Racks and units are assumed sizes that name no maker; a hall that is too small is refused with the dimension that is short. The units’ service zones are not assessed because the assumed units state none. Rack weight, from an assumed class by kW per rack, is spread over each row’s strip of floor and compared with the floor capacity you enter; the rows over it are named, and with no capacity entered nothing is compared. Cooling units, containment and cabling are not weighed. A cable tray and a busway are placed over every row and the chilled-water main is routed from an assumed entry to the units, kept off the rows; services closer than 100 mm, or leaving less than 0.3 m under the clear height, are named. Concept routing: no supports, fill or ratings. Two other layouts of the same hall, the rows turned and every rack at twice the load, are counted beside the design; adopting one is changing the inputs. The hall’s floor area is compared with the largest fire compartment in the Finnish fire decree, reading the hall as a one-storey workplace space; that reading is an assumption your fire designer replaces. Its volume as one gas suppression zone is stated and not assessed, because no open source sets a largest zone. Cooling, the floor’s own design and escape routes: always not assessed. | | Data-centre cooling plants | cooling-plant-topology@1, cooling-plant-pid@1, cooling-plant-tagging@1, cooling-plant-layout@1, cooling-plant-piping@1 (integrity); cooling-plant-efficiency-targets@1, cooling-plant-design-basis@1 (engineering) | A chilled-water loop from an IT load and two water temperatures: heat and flow by arithmetic, a count of assumed coolant distribution units, pipe sizes from a velocity limit, a P&ID drawn by our own patterns and pipe routed on a lattice, with straight-pipe friction on the routed lines. Up to four units on a header; a larger loop is refused. Your PUE, ERF and WUE targets are restated as annual energy and water at a constant IT load, using the ISO/IEC 30134 definitions. Beside them, an hourly estimate of cooling energy, PUE and WUE through a typical year (PVGIS) at the nearest of seven reference capitals in northern Europe to your project's country (Helsinki when none is set), for one assumed concept (a dry cooler ahead of a chiller, wetted in warm hours) on round assumptions of ours; it does not model your chiller or your controls. Choose a district-heating supply temperature and it also estimates the heat pump's lift and COP, the heat reused and the ERF it gives, on the assumption that the network takes all the heat whenever it is 15 °C or colder outside. Chiller, heat rejection, pump head, controls and redundancy: always not assessed. | | Data-centre power blocks | power-block-topology@1, power-block-clearances@1, power-block-sld-model@1 (integrity); power-block-ratings@1, power-block-feeders@1, power-block-fault-level@1 (bounds); power-block-design-basis@1 (engineering) | Transformers, generators, UPS modules and battery cabinets counted from an IT load, a cooling load and N, N+1 or 2N, on assumed equipment that names no maker. The single-line diagram is drawn from that model, and the topology check takes away each element the redundancy allows to fail and asks whether the load is still carried, from the grid and from the generators. Rooms are laid out with working space in front of each lineup (NEC values, illustrative) and a generator yard. One LV board above 6300 A fails the ratings check. The single-line is compared with the placed equipment by tag: every element placed once with its count, kind and rating, nothing placed that it does not draw, and in 2N no room holding both paths. LV feeders to the UPS modules and the cooling feeder get parallel runs of a pandapower cable type and a voltage drop, with no derating; the three-phase fault current at each LV board is estimated by the IEC 60909 method on an assumed grid and agrees with pandapower on the same case. Protection, cable derating, earthing and the grid connection: always not assessed. |

| Roof trusses | roof-truss-geometry@1 (integrity); roof-truss-member-screen@1, roof-truss-joints-bracing@1 (engineering) | A Fink or king-post timber truss from span, pitch and spacing, solved as pins and bars. Once you state the roof snow load, each member is screened for its axial force with buckling, and the top chord for its bending between joints, against EN 338 or EN 14080 class values with the partial and duration factors EN 1995-1-1 recommends; no national annex is read. Joints, nail plates, bracing, wind, uplift and deflection: always not assessed. | | Ground-mounted PV | pv-row-shading@1 (integrity); pv-structure@1 (engineering) | Fixed-tilt rows facing the equator, spaced so no row shades the next for a window around noon on a design day, using the open pvlib shading method; module count, kWp and post positions follow. The sun's position is simple solar-time geometry on flat ground. Posts, rails, piles, wind, snow, cabling and yield: always not assessed. | | Windows and doors | opening-template-bounds@1, kit-aperture-fit@1 (bounds) | The house opening rules on one opening, and whether each pinned kit’s aperture rule admits it. One kit’s rule is pinned to real files; the others are unbranded archetypes. | | Wood decks | dca6-scope@1, irc-r105-2-deck-exemption@1 (prescriptive); deck-layout-integrity@1 (integrity); deck-member-sizing@1 (engineering) | The DCA 6 scope limits and the IRC permit exemption as published; inside the scope, ledger, joists, rim, beam, posts, footings and decking counted on an assumed joist spacing and the entered beam span. Outside it, out of envelope. Sizing from the guide’s tables: always not assessed. | | Apartment blocks | fi-lift-required@1 (prescriptive); apartment-block-layout-integrity@1, apartment-block-schedule-fit@1 (integrity) | When Finnish decree 241/2017 section 7 requires a lift, on the storey count alone; and whether a published flat schedule fits the outline it is said to fit, inside a band that is ours and not a rule. Massing and a typical floor counted at even divisions, for two to eight storeys. The frame is a label: no structure, fire design or flat plan is modelled. | | Garages and outbuildings | outbuilding-route@1 (prescriptive); outbuilding-envelope-consistency@1 (integrity) | Which side of the published permit-light line the building falls, per jurisdiction, with every condition; and whether the entered volume agrees with the entered area and heights, on a shell at an assumed 4:3 proportion. | | Greenhouses, pergolas and saunas | garden-structure-route@1 (prescriptive); garden-structure-envelope-consistency@1 (integrity) | The same routes with the kind named, and the same volume comparison. A sauna’s stove, flue and fire separation are not evaluated. A pergola is posts on an assumed 3 m grid and encloses no volume, so its consistency check is not assessed. | | Exhibition stands | stand-approval-route@1 (prescriptive); stand-layout-integrity@1 (integrity); stand-stability@1 (engineering) | One venue’s published approval line and deadline; a footprint at an assumed 3:2 proportion, closed sides in assumed 1 m wall modules, a platform in panels. Stability is the venue’s lateral pressure times the drawn wall area: always not assessed. | | Furniture and joinery | cabinet-review-scope@1 (applicability); carcass-panel-arithmetic@1 (integrity) | Whether a professional review step exists here: unresolved until a professional takes on liability for it. Sides, top, bottom, back and an assumed number of shelves across the run, as a panel list: no grain, kerf, edge banding, nesting or hardware. |

Outbuildings are offered outside Germany, where thresholds are set per Land.

Every prescriptive check names the instrument it evaluates and the date it was read. Full list as of 10 September 2026.

Instrument	Read by
Finland, Building Act 751/2023 § 42: a dwelling or holiday home at any size; other buildings from 30 m² or 120 m³; an open shelter from 50 m²; five or more occupants	outbuilding-route@1, Finland regulation package
Finland, decree 1340/2025 on plans in machine-readable form: IFC 4.3.2.0 or newer, Reference View, IFC-SPF	Finland regulation package, the IFC export check
Finland, decree 1007/2017 on usability, §§ 3, 4, 14	storey-stair@1
Finland, decree 1008/2017 on dwellings, §§ 4, 5	storey-room-height@1, room-area@1, room-clear-height@1, room-daylight@1
Finland, decree 848/2017 on fire safety, §§ 29, 31: eight metres between buildings unless fire spread is prevented otherwise	plot-building-separation@1, room-egress@1
Finland, national annex to SFS-EN 1991-1-3, 4.1 and Figure 4.1	site-ground-snow-load@1
Finland, national annex to SFS-EN 1991-1-4, 4.2	site-wind-basic-velocity@1
Espoo permit guidance: the city’s 30 m² and 120 m³ thresholds and its intake (plot identifier, zoning, remaining building rights, use, area, volume)	The Espoo permit package
EN 1997-1, Section 6 and Annex D	bearing-resistance@1, Eurocode 7 packages
EN 1993-1-1: the input list for a single-storey portal frame, intake only	The steel portal-frame package
England, Planning Portal permitted development: single storey, eaves 2.5 m, overall 4 m or 3 m, 2.5 m within 2 m of a boundary, at most half the land, not forward of the principal elevation, no platform above 0.3 m, no sleeping, 10 m² on designated land. Building regulations and listed-building consent are named, not evaluated	outbuilding-route@1
United States, IRC R105.2 (2021, 2024): decks at most 200 sq ft, at most 30 in above grade, unattached, not serving the exit door; accessory structures one storey, detached, 200 sq ft. Local amendments not modelled	irc-r105-2-deck-exemption@1, outbuilding-route@1
United States, AWC DCA 6 (2015 IRC edition): single level, attached, length not exceeding width, posts at least 6×6, snow at most 40 psf, beam span at most 18 ft, a listed species, no hot tub	dca6-scope@1
Messe Frankfurt technical guidelines, FON 2024. Every venue publishes its own; only this one is sourced	stand-approval-route@1

A revision package holds DXF layouts, an IFC 4.3 model and CSV quantities, all generated from one revision, so a wall is the same wall in each.

• DXF and IFC files are read back and compared with the revision. A file that does not match is refused.
• Each file carries a hash and the revision, kit version and context package versions it came from.
• The test suite opens sample IFC, DXF, STEP and PDF exports with readers that share none of our code. What each reader checks is listed per format, with the test that checks it; it describes the samples, not each download.

The files are concept files, not a construction design: no notches, joints, connections or structural approval.

IFC and the Finnish model-form permit

Decree 1340/2025 fixes the form for Building Act § 60 model submissions: IFC 4.3.2.0, Reference View, per storey, with elements, spaces and apartments, origin in the national coordinate system. Since 11 September 2026 every IFC download is checked offline against 27 named rules from that decree, the RAVA3.5 property set specification and the buildingSMART Reference View rules, and reports rules met and gaps by name.

• Written: an ETRS-TM35FIN origin; every element marked as envelope or not, and as new; external walls, roof, floor structure and stair as assemblies of their members, typed by the national structural-system code where one exists; base quantities per member (length, section area, volume); rooms as typed spaces with area and volume, grouped as one dwelling.
• Gaps reported: designer and applicant core data, the national room-use code, the height datum of the origin, and stud walls not modelled as solids at built thickness.
• Finland runs no public IFC validator, so these rules run offline in Nordform.

The designer makes the submission, with the concept model as its starting point.

Every piece of evidence on a revision (checks, drawings, quantities, estimates, exports, renders, the concept sheet, a sign-off) declares what it depends on. On saving a new revision the engine compares it with the previous one and names why each piece went stale:

• Construction system: the kit changed.
• Dimensions: which of width, length, height and pitch moved.
• Openings: which were added, removed or resized.
• Kernel: inputs unchanged, but the geometry code produced a different frame.
• Context packages: a package a check reads was added or removed.
• Brief: the text changed, which affects the proposal and nothing deterministic.

Untouched evidence stays fresh. A sign-off is withdrawn and names the revision it belonged to.

Source packages are available for Sweden, Norway, Denmark, Germany, Austria, Switzerland, England, Ireland, the United States and Canada. England’s regulation, practice and submission packages require England to be selected as the constituent country; they are not selected for Scotland, Wales or Northern Ireland. Each records the building regulation and its edition, the permit routes with their thresholds and conditions, the responsible roles in the local language, and the working conventions. Each carries the status “sourced, applicability unverified”: sources cited and dated, for review by a professional in that jurisdiction. The packages provide orientation and applicability questions. Regional and municipal sources keep their own scope. In Germany, Austria and Switzerland, the responsible designer selects and reviews the local sources.

1. 1Dated sourceThe instrument, its edition and the date it was read. Undated content and machine translations do not count.
2. 2Context packageThe source recorded with its conditions and its status.
3. 3Deterministic checkThe rule as a check that states what it reads, what it does not read and where it stops.
4. 4AdvisoryThe check runs, labelled advisory, on every revision that selects it. Every check on this page is here today.
5. 5Boundary fixturesA golden set with independently verified results, covering the edges of the envelope.
6. 6Named professionalA professional in the jurisdiction accepts the check definitions, with date and version recorded.
7. 7QualifiedA pass is qualified for that family and jurisdiction until a source changes and the result goes stale.

The solid steps are done. The outlined steps are not: no workflow is qualified in any jurisdiction yet, so every result is advisory.

A language model never produces a pass, a solver never extrapolates outside its validated cases, and no check states that a design complies, is permitted or is approved.

The house family is the pilot. The timber-frame concept and Skylark 150 kits, the Lammi block wall and RunkoPES 2.0 are live. Every other family is illustrative and unsized. Storeys, rooms, site checks, the family catalog, scoped quotes, revision-bound sign-offs and change invalidation are live. Every check is advisory. The same status is shown in the product, the catalog and the roadmap.

Process plant concepts

A generic hydrogen-to-methane demo connects declared equipment and streams to deterministic routing, a 3D view, isometrics and PCF downloads. The signed-in workspace adds bounded P2M scenario inputs, immutable local revision history and downloadable evidence packages. Equipment and fitting dimensions are assumptions, and balances are fixed-assumption arithmetic; process simulation, P&ID validation, hydraulic and stress assessment and safety approval come from the responsible engineers. Scenario inputs are kept in your browser and exact output in the downloaded packages. Process-plant family projects save to the cloud like every other family.

Connected design navigation

A local connected-site workspace places massing, P2M plant equipment envelopes and the Finnoo block study together. Each placed design pins a source-input revision; its site translation and rotation remain separate. Edits produce candidates for preview and explicit site adoption. The display geometry is derived and does not become an engineering or export input. Typed dependency links watch recorded revisions and placement, propagate signals through linked designs, and select revision-alignment checks plus spatial, capacity or requirements review tasks. Review notes name exact dependency inputs; later changes require a fresh review. Account-scoped browser recovery and JSON backups include these links and notes.

• Every check is advisory. A result becomes more than advisory when a named professional accepts the checks at a stated version on a stated day.
• A language model never produces a pass, a solver never extrapolates outside its validated cases, and no check states that a design complies, is permitted or is approved.
• Every family other than the house is illustrative and unsized. Member sizing, connections, loads beyond the stated checks, fire and corrosion come from the responsible engineer.
• A country pack is prose the planner reads, with its sources and dates. A check reads only the figures listed above from it.