Window and Skylight Daylight Log

Window and Skylight Notes Need the Opening State

Daylight readings become easier to compare when the window, skylight or rooflight condition is written beside the value. A north-facing window with blinds open, a shaded kitchen skylight, a clerestory window, a deep eave and a partly drawn curtain can all create different readings at the same room point. The useful note names the opening, the point, the plane, the sky, the blind or shade state and whether electric light was present.

The detailed percentage check belongs with daylight factor reading notes and the daylight factor page when indoor and outdoor values are paired. One-point daylight lux readings can sit beside daylight lux values, lux meter reading notes and daylight vs electric lighting notes. Shading language belongs close to daylight shading and blinds reading notes.

The note should stay modest. It can say what was read at a point under a named opening state. It should not promise all-day daylight, seasonal daylight-factor performance, heat gain, cooling effect or a formal result for every sky.

Name point, plane and distance from the opening

A daylight value is not just a room value. It belongs to a point and a plane. A desk top beside a window, a kitchen bench under a skylight, a floor point in a hall and a vertical wall face near a clerestory are different readings. The task plane term helps keep the surface visible, while vertical illuminance notes help with upright walls, labels, faces and boards.

The task-plane notes table can hold plane, height and surface notes. The lux meter grid notes table is useful when a window side, room centre and rear point need stable labels. Larger point sets can later feed lux meter average only when plane and condition match.

Sky, blind and shade state belong beside the value

Australian daylight can change quickly with cloud, sun angle, eaves, awnings, trees, adjacent buildings and internal blinds. The meter value should travel with those conditions. A point read under bright overcast with blinds open is not the same as the same point under direct sun or a closed curtain.

When a cloud band moves during a reading set, write that plainly. A changed sky is not a reason to discard every value, but it is a reason to keep the set labelled with care.

Opening and shading state rows

Opening notes are most useful when they can be repeated later. Name the window or skylight, then keep the point label and plane steady while the opening, shade or control state changes.

Compare Daylight Lux, Daylight Factor and Electric Light

Lux and daylight factor answer related but different questions. A daylight lux value measures light arriving at an indoor point. A daylight-factor percentage compares an indoor daylight value with an outdoor reference value from the same daylight condition. Electric-light readings describe the active electric-light state, with or without daylight present.

The daylight factor vs daylight lux guide keeps that split clear. The daylight factor glossary entry is a short definition when the term appears in a note.

Window and skylight comparisons need tight boundaries

Comparing daylight readings can be useful, but the comparison should stay inside the conditions that were actually written down. A window-side point can be compared with an inner-room point under the same sky. A skylight point can be compared with a point away from the skylight in the same interval. A blind-open reading can be compared with a blind-closed reading when the point and plane are repeated.

This boundary is especially important for skylights. The note may describe daylight at points below or away from the opening, but it should not make claims about heat flow, condensation, roof performance or full-room daylight-factor outcomes.

Electric-light state and controls need a clear row

Many rooms are checked while electric lights are already on. That is acceptable when the note says the reading is combined. It becomes misleading when the value is later treated as daylight-only. The lighting control notes table keeps zone, scene, dimming range and daylight-linked state beside the value.

The dimming range term can help when dimmed states appear in the note. A lumens to lux estimate can sit beside a measured after-dark line, but it should not be blended into a daylight value.

Colour, glare and surface notes stay as companions

A daylight value can be numerically clear while the visible condition still needs a short note. Direct sun can create a bright patch. A skylight diffuser can brighten a bench while leaving a vertical face lower. A tinted window, pale wall, dark floor or glossy table can change the viewing condition. Keep these notes beside the point value rather than making the lux value carry every explanation.

These companion fields explain the condition around the reading. They do not turn a daylight note into a comfort rating, design sign-off or all-season outcome.

Compact Window or Skylight Daylight Worksheet

Related Daylight Checks

• Daylight factor reading notes
• Daylight factor vs daylight lux
• Daylight vs electric lighting notes
• Daylight shading and blinds reading notes
• Daylight factor
• Daylight lux values
• Daylight factor examples
• Lux meter reading notes
• Lux meter grid notes
• Task-plane notes
• Lighting control notes
• Disclaimer