Exceptionally quantitative archival account of an anonymized municipal civil-defence HC: 900 m² / 9,688 ft² over two floors inside an approximately 6,000 m³ cavern, reached by a 110 m blast tunnel. It reports about 1,800 m³ concrete, 60 t reinforcement, detailed finishes, a 72 kW standby plant, ventilation flows, 96 beds and exact excavation and complete-facility costs.

area_m2: value: 900 m² / 9,688 ft² | scope: focal HC gross floor area | note: Reported across two floors. | rock_volume_m3: value: 6000 | unit: m³ | scope: focal excavated cavern and access works | note: Article states approximately 6,000 m³; paid solid-design volume is not explicitly defined. | tunnel_length_m: value: 110 | unit: m | scope: entrance/blast tunnel | note: A blast pocket is reported at the end. | portals: value: 1 | unit: main portal | scope: focal HC | note: Main entrance through the 110 m tunnel; the emergency exit is separate. | shafts: value: 1 | unit: vertical emergency-exit shaft | scope: focal HC | note: Reported rise is approximately 15–20 m with 85 rungs. | inner_structure: value: freestanding two-storey reinforced-concrete building | scope: inside the excavated cavern | note: The principal occupied structure.; value: 1800 | unit: m³ concrete | scope: inner building | note: Approximate reported quantity.; value: 60 | unit: t reinforcement | scope: inner building | note: Approximate reported quantity. | levels: value: 2 | unit: floors | scope: inner building | note: Directly reported. | other: value: 96 | unit: beds | scope: two dormitory sections | note: 45 women's and 51 men's beds.; value: 1400 m² / 15,069 ft² gypsum partitions | scope: interior finishes | note: Other reported finishes include 640 m² / 6,889 ft² floor covering and 400 m² / 4,306 ft² suspended ceiling.

amount: SEK 450,000 | year: 1962 | basis: authorized amount | scope: Rock excavation only.; amount: SEK 5,100,000 | year: 2020 | basis: publisher-stated article-era equivalent | scope: Equivalent of the SEK 450,000 excavation authorization; method unstated.; amount: SEK 407,973 | year: 1965 | basis: approved eligible actual | scope: Rock excavation only.; amount: SEK 2,550,294 | year: 1972 | basis: approved actual | scope: Complete facility final account.; amount: SEK 18,000,000 | year: 2020 | basis: publisher-stated article-era equivalent | scope: Equivalent of the complete-facility final account; method unstated.; amount: SEK 250,000 | year: 1972 | basis: reported variance over estimate | scope: Non-additive complete-facility overrun; do not infer the original total budget without the underlying account.

72 kW standby power; Protective air filtration at 3,000 m³/h normally occupied and 600 m³/h under gas hazard; EMP-protected equipment room; External water tank, water/sewer and machine rooms; Radio, telephone exchange and command/operations rooms; Dormitories, hygiene spaces, small kitchen, dining room, guard room and stores

6,000 m³ rock excavation; 110 m protected access tunnel; 1,800 m³ underground concrete and 60 t reinforcement; 900 m² / 9,688 ft² interior fit-out; Standby power, filtered air, EMP and communications systems; Portal, escape shaft and utility interfaces

One municipal main command centre. The cost and quantity evidence is facility-specific rather than a program total.

Held after source-specific review.

Cavern and tunnel cross-sections; Rock-cover depth and geology; Portal and blast-door dimensions; Water-storage volume; Detailed MEP and communications schedule; Spall, shock and CBRN performance brief; Spill/haul quantities and disposal boundary

Identity must remain anonymized.; The source calls the 6,000 m³ excavation approximate; the model presents 6,000 solid-design m³ as though contractually exact.; The reported SEK 250,000 overrun is a variance, not an additional project to add to the final account.; Publisher 'today' equivalents lack a stated price date/method and should not be mixed with dossier CPI/BKI outputs.