Library (legend) — an ArchLang floor plan example
A public library around a circular reading room, issued on a sheet with a room schedule and a fixture legend.
This plan compiles to 14 rooms, 1545.06 m² of floor area and 16 windows; every room is reachable from the entrance.
The source
This is the whole plan. The drawing above is what the compiler produced from it — nothing was drawn by hand.
# A ~50 x 32 m public library around a circular reading room — the SHEET-AND-TABLES example.
#
# 1. CURVED GEOMETRY. The reading room is a drum: a `room circle` for the floor and a
# `wall` of `arc` edges for the enclosure, the pair `examples/aquarium.arch` introduces.
# The drum is INSCRIBED in the 16 x 16 m central bay, so it is tangent to all four bay
# walls and every tangent point is a threshold; the four corner spandrels it leaves
# (~14 m2 each) belong to no room and carry no schedule row. The circle is written as
# EIGHT arcs rather than the two semicircles the shape needs, deliberately: the analysis
# grid behind `describe --json`'s `circulation` rasterises a wall between its VERTICES,
# so two semicircles lay a phantom chord straight across the room and report the walk to
# it at 5x its true length. Eight keeps every chord inside the face it stands for, and
# the DRAWING is identical either way — every face is a true arc, at any zoom.
#
# 2. THE SHEET. `paper A2 landscape` + `scale 1:200` fixes every annotation at a size ON
# THE SHEET instead of a fraction of a 50 m building, and `schedule rooms` + `legend`
# fill the margin. Both tables are fully derived, nothing to configure: the legend lists
# one row per wall hatch MATERIAL used (`concrete` for the shell, the default poche for
# the partitions) and one per placed fixture CATEGORY that has a plan symbol — wc, basin,
# kitchen_sink, counter, fridge, stove. Use neither and the table comes out empty.
#
# 3. THE EXPLICIT CURVE CALL-OUTS at the foot of the file. `dim radius <wallId> segment <n>`
# and `dim diameter <roomId>` take BOTH geometry and text from the element they name, so
# R8000 and the centre are never retyped. `dims auto` already synthesizes one R per
# DISTINCT arc (deduplicated by centre+radius, so this eight-arc circle still gets one)
# and one phi per circular room, in every mode but `walls` — so these two statements are
# what the sheet would still carry with `dims auto` switched off, and they cost nothing
# while it is on. Both are zero-offset by contract, which is exactly why neither can trip
# `W_DIM_INSIDE` or `W_DIM_OVERLAP`: a zero-offset dim sits ON what it measures.
#
# Departments are `zone`s — declared, never inferred from position, and carrying zero
# geometric semantics: the SVG is byte-identical without them. All they add is `zones[]` on
# `describe --json` and the subtotal grouping in the room schedule.
plan "Reading Room Library" {
units mm
# `grid 50`, not 100: the partitions are 200 thick and the shell 300, so a fixture
# placed `flush` against the shell lands on a ...50 coordinate (32000 - 150). A grid of
# 100 could not express that face and would snap the fixture back into the wall.
grid 50
paper A2 landscape
scale 1:200
north up
dims auto all
schedule rooms
legend
# ---- structure: shell in `material concrete`, partitions in the default poche ------
wall id=shell exterior thickness 300 material concrete { (0,0) (50000,0) (50000,32000) (0,32000) close }
# The two spine walls: west wing | central bay | east wing.
wall id=w_west partition thickness 200 { (17000,0) (17000,32000) }
wall id=w_east partition thickness 200 { (33000,0) (33000,32000) }
# The bay's cross walls, and the drum inscribed between all four.
wall id=w_ref_s partition thickness 200 { (17000,8000) (33000,8000) }
wall id=w_hall_n partition thickness 200 { (17000,24000) (33000,24000) }
# Every vertex below is an exact grid-50 point at R8000 from (25000,16000) — 4800/6400 is
# a 3-4-5 triple scaled — so the eight arcs close a true circle. Walked from the EAST
# point the default `ccw` runs east -> north -> west -> south, which puts the thresholds
# at 25% (north), 50% (west) and 75% (south) of the wall's RUN; an arc contributes its
# arc length R*theta to that run, never its chord.
wall id=w_drum partition thickness 200 {
(33000,16000)
arc (29800,9600) radius 8000
arc (25000,8000) radius 8000
arc (20200,9600) radius 8000
arc (17000,16000) radius 8000
arc (20200,22400) radius 8000
arc (25000,24000) radius 8000
arc (29800,22400) radius 8000
arc (33000,16000) radius 8000
}
# Both wings carry a 3 m aisle on the drum's centre line, so each meets it at a tangent.
wall id=w_waisle_n partition thickness 200 { (0,14500) (17000,14500) }
wall id=w_waisle_s partition thickness 200 { (0,17500) (17000,17500) }
wall id=w_cafe_e partition thickness 200 { (44000,0) (44000,14500) }
wall id=w_eaisle_n partition thickness 200 { (33000,14500) (50000,14500) }
wall id=w_eaisle_s partition thickness 200 { (33000,17500) (50000,17500) }
wall id=w_staff_s partition thickness 200 { (33000,24000) (50000,24000) }
wall id=w_lobby_s partition thickness 200 { (33000,27000) (50000,27000) }
wall id=w_wcw_e partition thickness 200 { (39000,27000) (39000,32000) }
wall id=w_wcm_e partition thickness 200 { (45000,27000) (45000,32000) }
# ---- axes: the STRAIGHT structural grid only; a curve's radius is its dimension ----
axes {
x at 0, 17000, 33000, 44000, 50000
y at 0, 14500, 17500, 24000, 27000, 32000
}
# ---- rooms, grouped by department -----------------------------------------
zone public "Public" {
room id=r_hall at (17000,24000) size 16000x8000 label "Entrance Hall" uses entry hall
room id=r_reading circle at (25000,16000) radius 8000 label "Reading Room" at (25000,17200) uses hall
room id=r_children at (0,17500) size 17000x14500 label "Children's Library" uses living
room id=r_waisle at (0,14500) size 17000x3000 label "West Aisle" uses circulation
room id=r_cafe at (33000,0) size 11000x14500 label "Cafe" uses dining
room id=r_eaisle at (33000,14500) size 17000x3000 label "East Aisle" uses circulation
room id=r_lobby at (33000,24000) size 17000x3000 label "WC Lobby" uses circulation
room id=r_wc_w at (33000,27000) size 6000x5000 label "WC Women" uses wc
room id=r_wc_m at (39000,27000) size 6000x5000 label "WC Men" uses wc
}
zone stacks "Stacks" {
room id=r_stacks at (0,0) size 17000x14500 label "Open Stacks" at (8500,12400) uses storage
room id=r_ref at (17000,0) size 16000x8000 label "Reference Stacks" uses storage
}
zone staff "Staff" {
room id=r_staff at (33000,17500) size 17000x6500 label "Staff Workroom" uses office
room id=r_kitchen at (44000,0) size 6000x14500 label "Cafe Kitchen" uses kitchen
room id=r_plant at (45000,27000) size 5000x5000 label "Plant Room" uses utility
}
# ---- thresholds -----------------------------------------------------------
# The drum is tangent to each bay wall at one point, so a threshold there has to be cut
# through BOTH faces — the arc and the straight wall it touches — or the poche of the
# second one still stands in the doorway. Each pair below is one physical opening.
opening id=o_drum_s on w_drum at 75% width 3000
opening id=o_hall_n on w_hall_n at 50% width 3000
opening id=o_drum_n on w_drum at 25% width 3000
opening id=o_ref_s on w_ref_s at 50% width 3000
opening id=o_drum_w on w_drum at 50% width 2400
opening id=o_west_16 on w_west at 16000 width 2400
# The rest of the public route.
door id=d_main at (25000,32000) width 2400 wall shell swing into r_hall
opening id=o_hall_children on w_west at 28000 width 3000
opening id=o_hall_lobby on w_east at 25500 width 3000
opening id=o_ref_stacks on w_west at 4000 width 2400
opening id=o_stacks_aisle on w_waisle_n at 50% width 3000
opening id=o_children_aisle on w_waisle_s at 50% width 3000
opening id=o_cafe_aisle on w_eaisle_n at 5500 width 3000
opening id=o_staff_aisle on w_eaisle_s at 8500 width 2400
# Staff and service doors. The cafe kitchen keeps a pocket door off the aisle so no leaf
# swings into a 3 m corridor, and its own service door onto the east yard.
door id=d_kitchen pocket on w_eaisle_n at 14000 width 1000 slide right
door id=d_cafe_kitchen on w_cafe_e at 50% width 1000 swing into r_kitchen
door id=d_service at (50000,13000) width 1200 wall shell swing out
door id=d_staff_lobby on w_staff_s at 2500 width 1000 swing into r_lobby
door id=d_wc_w on w_lobby_s at 1500 width 1000 swing into r_wc_w
door id=d_wc_m on w_lobby_s at 7500 width 1000 swing into r_wc_m
door id=d_plant on w_lobby_s at 13000 width 900 swing into r_plant
# ---- glazing --------------------------------------------------------------
window at (6000,0) width 4000 wall shell
window at (12000,0) width 4000 wall shell
window at (21000,0) width 3000 wall shell
window at (29000,0) width 3000 wall shell
window at (38500,0) width 4000 wall shell
window at (0,6000) width 3000 wall shell
window at (0,16000) width 2000 wall shell
window at (0,24000) width 4000 wall shell
window at (50000,10500) width 1600 wall shell
window at (50000,20500) width 3000 wall shell
window at (6000,32000) width 4000 wall shell
window at (12000,32000) width 4000 wall shell
window at (20000,32000) width 3000 wall shell
window at (30000,32000) width 3000 wall shell
window at (36000,32000) width 1200 wall shell
window at (42000,32000) width 1200 wall shell
# ---- vertical circulation, side by side in the hall -----------------------
# A single-storey plan still draws both symbols; `W_STAIR_UNMATCHED` is a multi-storey
# question and never fires here.
stair id=st_main at (28500,26500) size 1400x4500 dir up
elevator id=lift_main at (30500,28000) size 2200x2200
# ---- fit-out --------------------------------------------------------------
# Reading tables ride the drum's chord lines, leaving the centre band clear for the phi
# call-out and the west threshold.
furniture table at (21500,9800) size 7000x1400 label "Reading table"
furniture table at (20500,12200) size 9000x1400 label "Reading table"
furniture table at (20500,18400) size 9000x1400 label "Reading table"
furniture table at (21500,20800) size 7000x1400 label "Reading table"
for i in 0..5 {
furniture shelf at (2000, 1500 + i * 2200) size 13000x600 label "Stacks"
}
for i in 0..4 {
furniture shelf at (18500 + i * 3200, 1200) size 600x5000 label "Reference"
}
for i in 0..3 {
furniture table at (2500 + i * 4500, 19500) size 2000x2000 label "Table"
furniture table at (2500 + i * 4500, 23500) size 2000x2000 label "Table"
furniture shelf at (2000 + i * 4500, 28500) size 3000x500 label "Picture books"
}
for i in 0..5 {
furniture desk at (34500 + i * 3000, 18500) size 1600x800 label "Desk"
furniture desk at (34500 + i * 3000, 22000) size 1600x800 label "Desk"
}
for i in 0..3 {
furniture table at (34500 + i * 3000, 2500) size 1600x1600 label "Table"
furniture table at (34500 + i * 3000, 6500) size 1600x1600 label "Table"
}
furniture sofa at (2000,27500) size 2400x900 label "Story bench"
furniture sofa at (18000,30000) size 2400x900 label "Seating"
furniture sofa at (21000,30000) size 2400x900 label "Seating"
furniture counter against wall w_hall_n offset 4000 size 4000x700 label "Enquiries" in r_hall
furniture plant at (18500,29000) size 700x700 in r_hall
furniture counter against wall w_cafe_e offset 3000 size 4000x700 label "Servery" in r_cafe
# Catalogued fixtures need no `size`: the footprint, the depth off the wall face and the
# quarter-turn all come from the wall and the catalogue.
furniture table at (45000,2500) size 3600x900 label "Prep"
furniture table at (45000,4600) size 3600x900 label "Prep"
furniture kitchen_sink against wall shell segment 1 offset 2000 in r_kitchen
furniture counter against wall shell segment 1 offset 3600 in r_kitchen
furniture fridge against wall shell segment 1 offset 5200 in r_kitchen
furniture stove against wall shell segment 1 offset 6800 in r_kitchen
furniture wc against wall shell segment 2 offset 11500 in r_wc_w
furniture wc against wall shell segment 2 offset 13000 in r_wc_w
furniture wc against wall shell segment 2 offset 14500 in r_wc_w
furniture basin against wall w_east offset 28000 in r_wc_w
furniture basin against wall w_east offset 29500 in r_wc_w
furniture wc against wall shell segment 2 offset 5500 in r_wc_m
furniture wc against wall shell segment 2 offset 7000 in r_wc_m
furniture wc against wall shell segment 2 offset 8500 in r_wc_m
furniture basin against wall w_wcw_e offset 1000 in r_wc_m
furniture basin against wall w_wcw_e offset 2500 in r_wc_m
# ---- the explicit curve call-outs (see the head of the file) --------------
dim radius w_drum segment 0
dim diameter r_reading
title {
project "Reading Room Library"
drawn_by "ArchLang"
date "2026-08-16"
}
}