> ## Documentation Index > Fetch the complete documentation index at: https://docs.ploterr.com/llms.txt > Use this file to discover all available pages before exploring further. # Pure edits > Apply one edit command to a model without a session. A pure edit applies one edit command to a building model and returns a new model. It needs no session, and it does not change the model that you give. Use it on a server, in a test, or when you do not need geometry. ## Import ```typescript theme={null} import { applyBuildingEdit, applyBuildingEditResolved, massSegmentHeightCommand, BmEditError, } from '@opengeometry/floorkit'; ``` ## Example ```typescript theme={null} import { applyBuildingEdit, BmEditError, type BmColumn, type BuildingModel, } from '@opengeometry/floorkit'; export function withColumn(model: BuildingModel, column: BmColumn): BuildingModel | undefined { try { return applyBuildingEdit(model, { kind: 'add-element', buildingId: 'building', storeyId: 'ground', list: 'columns', element: column, }); } catch (error) { if (error instanceof BmEditError) { console.error(error.code, error.message); return undefined; } throw error; } } ``` ## Notes * Both functions take a [`BuildingEditCommand`](/floorkit/api/editor/building-session#buildingeditcommand). `applyBuildingEditResolved` takes each `kind`. `applyBuildingEdit` rejects some wall and opening commands, such as `create-wall` and `add-hosted-opening`, with the code `resolved-edit-required`. * `add-element`, `replace-element` and `remove-element` change one entry of a list of a storey: `slabs`, `roofs`, `spaces`, `stairs`, `columns`, `beams`, `railings` or `instances`. `add-element` rejects an id that the list has. `replace-element` and `remove-element` reject an id that the list does not have. The new element of `replace-element` must have the same id. * `add-asset`, `replace-asset` and `remove-asset` change one asset of the model. `add-asset` rejects an id that exists. `replace-asset` and `remove-asset` reject an id that does not exist. `remove-asset` rejects an asset that an instance uses. * `add-storey`, `remove-storey` and `replace-storey-settings` change the storeys of one building. `add-storey` rejects a storey id that the building has. `remove-storey` rejects the last storey of a building. `replace-storey-settings` replaces the `name`, the `elevation`, the `height`, the `usage` and the `areaKind` together. The `areaKind` is what the plate of the storey counts as (`gross`, `balcony`, `core`, `basement`, `parking` or `mechanical`); a value that is not one of these is refused as `invalid-command`. * `replace-mass` sets the mass of one building and the settings of all its storeys. A storey id that stays keeps its elements, a new id adds an empty storey, and a storey that is left out is removed. It rejects the removal of a storey that holds an element. `massSegmentHeightCommand(model, buildingId, segmentId, height)` gives this command for a new height of one segment. * `add-building` adds a whole building, last in the list: its storeys, their elements and its optional `mass`. Each id in it must be new in the whole model. The smallest valid building has one storey, and for a massing study a `mass` with one segment whose `storeyIds` names that storey and whose `height` is the height of the storey. `remove-building` removes a building and all it holds; it rejects the last building of the model. * `replace-site` replaces the site whole: `boundary`, `lotLines`, `elevation`, `geoAnchor`, `trueNorthDeg` and the `zoning` rules. Without `site`, the model has no site any more. The model check refuses a self-intersecting boundary and a `lotLines` list that does not have one class per boundary edge. Run `evaluateZoning` again after the step; the command does not run it. * A `batch` applies its `commands` in order and returns one model. If one command fails, the error has the code of that command, and its message starts with the place of the command, such as `command 2 of 3:`. A batch cannot be empty and cannot hold a batch. * A rejected command throws `BmEditError`. The model that you gave is not changed. * The functions check the full result. For an edit in an app, use a [`BuildingSession`](/floorkit/api/editor/building-session). It also builds the geometry and keeps undo and redo. ## applyBuildingEdit Apply one saved edit of a building model, or one batch of edits, and return a validated new model. ```typescript theme={null} function applyBuildingEdit(model: BuildingModel, command: BuildingEditCommand): BuildingModel; ``` **Throws:** \{BmEditError} If the command, target, or resulting geometry is invalid. ## applyBuildingEditResolved Apply an immutable edit with exact junction-aware hosted-opening decisions. ```typescript theme={null} function applyBuildingEditResolved( model: BuildingModel, command: BuildingEditCommand, ): BuildingModel; ``` ## massSegmentHeightCommand The `replace-mass` command that gives one segment of a saved mass the height `height`, snapped to whole storeys at the pitch of its top storey; `undefined` when the snapped height is the saved one. ```typescript theme={null} function massSegmentHeightCommand( model: Readonly, buildingId: string, segmentId: string, height: number, ): ReplaceMassCommand | undefined; ``` ## BmEditError A rejected edit; `issues` carries model-validation details when available. ```typescript theme={null} class BmEditError extends Error { readonly code: BmEditErrorCode; readonly issues?: BmIssue[]; constructor(code: BmEditErrorCode, message: string, issues?: BmIssue[]); } ``` ## Types ### BmEditErrorCode Stable category for a rejected building edit. ```typescript theme={null} type BmEditErrorCode = | 'invalid-command' | 'invalid-target' | 'hosted-openings-unsupported' | 'join-overrides-unsupported' | 'resolved-edit-required' | 'kernel-unavailable' | 'invalid-geometry'; ``` ### ReplaceMassCommand Replace the mass of a building and the settings of its whole storey list in one step. ```typescript theme={null} interface ReplaceMassCommand { kind: 'replace-mass'; buildingId: string; mass?: BmMass; storeys: MassStoreySettings[]; } ``` ### MassStoreySettings The settings of one storey in a `replace-mass` command; its elements are not part of it. ```typescript theme={null} interface MassStoreySettings { id: string; name?: string; elevation: number; height: number; usage?: string; areaKind?: AreaKind; } ``` World Y of the floor of the storey, in metres. Floor-to-floor height in metres. What the plate of the storey counts as; see `BmStorey.areaKind`. ### BuildingCommand Add or remove a whole building of a model. ```typescript theme={null} type BuildingCommand = | { kind: 'add-building'; building: BmBuilding; } | { kind: 'remove-building'; buildingId: string; }; ``` ### ReplaceSiteCommand Replace the site of a model whole: boundary, lot lines, grade, geo anchor, true north and zoning rules. ```typescript theme={null} interface ReplaceSiteCommand { kind: 'replace-site'; site?: BmSite; } ``` ## Related * [`AreaKind`](/floorkit/api/architecture/massing-helpers#areakind) * [`BmBuilding`](/floorkit/api/architecture/validate-building-model#bmbuilding) * [`BmIssue`](/floorkit/api/architecture/validate-building-model#bmissue) * [`BmMass`](/floorkit/api/architecture/validate-building-model#bmmass) * [`BmSite`](/floorkit/api/architecture/validate-building-model#bmsite) * [`BuildingEditCommand`](/floorkit/api/editor/building-session#buildingeditcommand) * [`BuildingModel`](/floorkit/api/architecture/validate-building-model#buildingmodel) This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.