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ADR-039: DOE skylights by atlas family, from each family's source geometry

  • Status: Accepted; decision 4 amended by D-252 (2026-11-01)
  • Date: 2026-11-01
  • Decision log: D-249, D-250, D-252
  • Design note: stage BG4 §3 and §4; stage BG5 for decision 4
  • Amends: ADR-036 decision 7 (an atlas map's presets keep the DOE reference building's glazing) for skylights

Context

BEMGen's DOE layout records take their geometry and glazing from one source: the DOE commercial reference buildings v1.4, new construction (2004), Chicago (D-160). Their skylights are those of that file: the schools' gyms only. A DOE Programs component's atlas map kept that glazing for every family (ADR-036 decision 7), so the 90.1 and IECC retail and warehouse had no skylights, while their source models have them; BG3's prototype check of code-rule daylighting found the controlled floor fractions 0.066 and 0.052 against PNNL's 0.698 and 1.000 (D-235). The owner's answer G6 (2026-11-01, "follow the source evidence"): add skylights only where the source geometry carries them, per family where they differ.

Decision

  1. Each family's skylights are its source geometry's. The families' source models: DOE Ref pre-1980 and 1980–2004 the DOE Ref v1.4 pre-1980 and post-1980 IDFs (16 climates); 90.1-2007, 2013, 2019 and IECC 2006 to 2021 the PNNL prototype IDFs (19 climates); the supermarket, which PNNL does not model, the geometry OSM openstudio-standards names for the 90.1 template. scripts/doe-geometry/family_skylights.py reads every file, sums the skylight area of each program key's source zones, groups the climates with the same skylights, and writes src/Lod.Generators/Doe/Skylights/family-skylights.json (embedded, --check reproduces it byte for byte). The ratio is over the key's source roof area of the answer key, the basis of the record's own ratio.
  2. What they say. No DOE Ref pre-1980 or 1980–2004 model has a skylight, not even the schools'. 90.1-2007 and IECC 2006 and 2009: the retail core 6.689 m², the warehouse bulk storage 14.8645 m², the schools' gyms as the records. 90.1-2013, 2019, IECC 2015 to 2021: the retail core 23.7832 m², the warehouse bulk 47.5664 and fine storage 20.8103 m², except in 6A, 6B, 7A, and 8A, where the models keep the 90.1-2004/2007 skylights (openstudio-standards' model_custom_geometry_tweaks of the retail and the warehouse does the same); IECC 2012: the retail core 23.7832 m² and the warehouse bulk 71.3495 and fine 25.2696 m² in every climate. The supermarket's sales 35.6748 m² in 90.1-2013 and 2019. No other type has a skylight in any family. The openstudio-standards template geometries agree with the PNNL models' groups outside 6A to 8A.
  3. Where they are used. DoeProgramPresets.KeyRatios(type, key, template, climateZone) keeps the record's window ratios and takes the family's skylight ratio in the climate zone. A climate zone outside every group, or none, takes the template's own geometry (the group of the most climates) with ClimateZoneAssumed. The DOE Programs components use it for an atlas map (the map's family and the Climate Zone input, with a warning when the zone is assumed); the test-suite generator's record glazing uses it for a DOE slot whose programs are of one family (their JSON's atlas ID). The illustrative presets keep the record's glazing (the New2004 file's).
  4. The skylights' layout is the source's (amended by D-252; it was BEMGen's, one centred skylight per ceiling, S5). family_skylights.py also records, per key and skylight ratio, the source's skylights as rectangles in the frame of the key's source roof (layouts in family-skylights.json, format version 2, with where each was found; the layout record's New2004 gyms equal the PNNL ones). A DOE generator's zone whose preset has a source's ratio gets that layout: the frame mapped onto the zone's roof's bounding box, each skylight's centre scaled with the roof, every skylight scaled alike to the key's skylight area (BG4's ratio × the roof); where one would leave the roof or meet another at the plan's dimensions, one centred skylight of that area with the warning SkylightLayoutNotFitted. Any other ratio keeps one centred skylight (S5). A roof that a later step leaves unchanged keeps the layout; a merged or split one takes one centred skylight of the area under it (ADR-012).

Consequences

  • An atlas map or a record-glazing suite of the retail, the warehouse, or the supermarket in a family whose source has skylights gets toplit roofs; the schools' gyms lose theirs in the DOE Ref families. The window area is unchanged everywhere.
  • With code-rule daylighting on, the 90.1-2019 5A retail and warehouse match PNNL's controlled floor fraction (0.698 and 1.000). With one centred skylight they controlled less lighting (0.090 against 0.387; 0.208 against 0.492, D-250); with the source's layout (D-252) 0.402 and 0.618: the toplit areas are the source's, and what is left is the code rule's geometric shares (0.515 retail core, 0.528 bulk, 0.710 fine storage) against PNNL's fixed 0.25 + 0.25, and the warehouse office (G4).
  • The LOD study's published results, made with the record's glazing at BEMGen 8d2e3bd on atlas 2.0.0 inputs, stay as they are (D-244).

Alternatives

  • One layout record per family. Rejected: the families share the DOE Ref plan and zones; only the skylights differ, and the atlas maps already carry the family.
  • openstudio-standards' geometry for every 90.1 family. Equivalent outside 6A to 8A; the PNNL models are the atlas's prototype source for the IECC families and carry the climate variants as written files, so they are read for 90.1 too, and openstudio-standards only where PNNL has no model.
  • The source's skylight count and spacing. Not taken in BG4: it changes the generators' skylight rule (S5), which G6 did not ask for. Taken in BG5 (D-252, decision 4), on the owner's principle "follow the source evidence".
  • Fitting a regular grid of the source's count and size to any roof (D-252). Rejected: the sources put the retail's, warehouse's, and supermarket's skylights in one part of the roof, not over the whole of it; a grid over the roof would light more of it than the source does.