Build your own house: walls, windows, doors, floors, roof, stairs, furniture

House parts (stdlib isokit/house): house_wall drawn along a line, with ends
that adapt at corners, T-junctions and straight runs so no two walls
overlap; window and door that sit on a wall and cut its opening (door
styles panel, glass, double, sliding, opening; swing and hinge by
rotation); floor (boards, tiles, carpet, stone); roof (hip, gable, flat,
optional solar); stairs.

Furniture (stdlib isokit/furniture): chair, sofa / armchair, table with
chairs, desk with monitor and chair, TV, bed, cupboard, bookshelf, kitchen
run, bathtub, shower, toilet, washbasin, plant, rug, floor lamp.

Cut-open levels: on gf / 1f the walls in front of a room are cut low
(rooms are found by their floors), the roof becomes an outline on the
floor, and storeys above are left out. A part's storey comes from z
(storey_h, default 3 m).

Scripting: objects_of, objects_at, objects_on, mount_of, mounted, frame,
to_world, to_local, local_of. Prefab meta: shape (line / rect), mount,
storey.

Studio: drag to draw lines and rectangles (walls, roads, fences, hedges,
floors, areas, buildings, roofs). The Room tool draws a floor plus walls,
without doubling walls that already stand on an edge. Windows and doors
snap onto walls with a hover preview, and they move, turn, copy and
delete with their wall in one undo step. New parts land on the storey
the view shows. Palette categories collapse, and the palette scrolls
apart from the object list.

The MCP instructions explain house building, and list_prefabs shows
sits_on. examples/house is a furnished bungalow; the web Studio gets a
House demo button. Tests: wall corners and junctions, zero depth-sort
cycles in every view, cut levels, and the house demo in every view;
check_studio covers the room / window / door / storey flow, check_web
the House demo.

web/web.js

@@ -367,7 +367,7 @@ function injectUI() {
     '<h3>Projects</h3>' +
     '<div class="wb-cur" id="wb-cur"></div>' +
     '<ul class="wb-plist" id="wb-plist"></ul>' +
-    '<div class="wb-new"><input id="wb-ntitle" placeholder="Title of a new project" autocomplete="off"><button type="button" id="wb-ncreate">New project</button><button type="button" id="wb-ndemo" title="A fresh copy of the demo scene">Demo copy</button></div>' +
+    '<div class="wb-new"><input id="wb-ntitle" placeholder="Title of a new project" autocomplete="off"><button type="button" id="wb-ncreate">New project</button><button type="button" id="wb-ndemo" title="A fresh copy of the demo scene">Demo copy</button><button type="button" id="wb-nhouse" title="A house built from parts: walls, windows, doors, floors, furniture">House demo</button></div>' +
     '<div class="wb-drop" id="wb-drop">Import: drop a project folder or .zip here, or <button type="button" id="wb-izip" title="Import a project .zip into this browser">.zip…</button><button type="button" id="wb-idir" title="Copy a project folder into this browser">folder…</button>' +
     (canOpenFolder ? '<span class="st-grow"></span><button type="button" id="wb-ofolder" title="Edit the files in the folder on disk directly; changes made there show up live">Open folder live…</button>' : "") + "</div>" +
     '<p class="st-help">Projects are kept in this browser. ' + (canOpenFolder ? "A folder opened live is edited on disk, so agents (<b>isokit mcp</b>), editors and git see the same files." : "To edit a folder on disk directly, use Chrome or Edge.") + "</p>" +
@@ -417,6 +417,7 @@ function wireProjects() {
   });
   $("wb-ntitle").addEventListener("keydown", function (e) { if (e.key === "Enter") $("wb-ncreate").click(); });
   $("wb-ndemo").addEventListener("click", async function () { openProject((await createProject(await demoFiles())).id); });
+  $("wb-nhouse").addEventListener("click", async function () { openProject((await createProject(await demoFiles("house.json"))).id); });
   $("wb-izip").addEventListener("click", function () { $("wb-fzip").click(); });
   $("wb-idir").addEventListener("click", function () { $("wb-fdir").click(); });
   $("wb-fzip").addEventListener("change", function () { var f = this.files[0]; if (f) importZip(f); this.value = ""; });
@@ -468,7 +469,7 @@ function exportZip() {
   download(name + ".zip", zip(P.files, name + "/"));
   toast("Exported " + name + ".zip");
 }
-async function demoFiles() { return (await fetch(asset("demo.json"))).json(); }
+async function demoFiles(name) { return (await fetch(asset(name || "demo.json"))).json(); }
 
 // the code editor: the project's files, applied as one outside edit
 var C = { path: null, dirty: false };