How to use the Daylight Study
Collect room geometry, aperture sizes, glass transmission, frame fraction, sky-angle and maintenance assumptions from a named model, drawing or product source.
The workspace starts blank. Load example temporarily fills the controls with demonstration data; reload or use the tool’s New or reset action, where provided, before entering live information.
- Choose Region and Units, then enter Study / room reference, width, depth, height, average reflectance and Model / drawing source.
- Add each window or rooflight with type, dimensions and quantity.
- Enter Glass transmission, Frame factor, Sky angle, Maintenance and Product / model source for each aperture.
- Review the effective opening areas and concept-stage daylight proxy, then compare options with one controlled change at a time.
Worked examples
These examples explain the set-up, expected output and review needed without changing the tool workspace.
Window-size option study
- Set-up
- Duplicate one room and change only the window width or quantity while keeping room, glass, frame, sky and maintenance inputs fixed.
- Result
- The proxy shows the relative effect of additional effective aperture area.
- Review
- Check overheating, glare, views, facade composition and a detailed climate-based model before selecting the option.
Rooflight assumption record
- Set-up
- Enter rooflight dimensions, quantity, glass transmission, frame factor and sky angle with the current product and roof-plan references.
- Result
- The output makes losses between structural opening and effective aperture visible.
- Review
- Confirm obstruction, reveal, dirt depreciation and actual product data in the detailed simulation.
Suggested workflow
Place the tool in a controlled project or practice process rather than treating its output as an isolated verdict.
- Reference the room and aperture geometry and agree consistent optical assumptions.
- Use the proxy to compare early options rather than claim a target or compliance result.
- Develop the preferred option in an appropriate climate-based daylight, glare and overheating assessment.
Check before saving or issuing
- Room and aperture dimensions come from the same coordinated revision.
- Transmission, frame and maintenance factors are entered as fractions and have a source.
- Comparisons alter only the intended design variable.
Common problems
- Result is unexpectedly near zero: check glass transmission, frame factor, sky angle and maintenance values for percentages entered as whole numbers.
- Rooflights seem too effective: verify quantity, structural opening, framing and obstruction assumptions.
- A higher proxy is treated as better: review glare, solar gains, distribution and the project daylight criteria separately.
Output
An aperture register, effective opening areas and a reproducible daylight proxy.
Professional boundary
This is not a BS EN 17037, BRE BR 209, LEED, planning or climate-based daylight assessment.