Calculator Input

Example Data Table

Formula Used

Effective Projection = Overhang Depth − Reveal Depth

Normal Projection = Effective Projection × cos(Azimuth Offset)

Shadow Drop = Normal Projection × tan(Solar Altitude)

Shadow Reach Into Opening = Shadow Drop − Gap Above Window

Shaded Height = minimum(Window Height, positive Shadow Reach)

Window Shading % = (Shaded Height ÷ Window Height) × 100

Side Shadow Reach = Effective Side Fin × tan(Azimuth Offset)

Required Overhang = ((Gap Above + Target Shaded Height) ÷ (tan(Altitude) × cos(Azimuth Offset))) + Reveal Depth

This method uses simplified façade geometry. It is useful for early design, envelope studies, and quick sun control checks during construction planning.

How to Use This Calculator

1. Select meters or feet.
2. Enter window width and window height.
3. Enter the gap between the top of the window and the underside of the overhang.
4. Enter overhang depth and any side fin depth.
5. Enter reveal depth if the frame is recessed.
6. Enter the solar altitude and the azimuth offset from the façade normal.
7. Set a target shading percentage if you want a recommended overhang depth.
8. Click Calculate Projection to see shading height, shadow reach, and suggested overhang values.
9. Use the CSV or PDF buttons to save the current report and recent calculation history.

Sunshade Projection in Construction

Sunshade projection affects glare control, cooling demand, and occupant comfort. A well-sized overhang blocks high seasonal sun and still allows balanced daylight. This calculator helps designers, estimators, and site teams test a window opening against practical geometry. It supports quick façade checks during concept design, detailing, and value engineering.

Why projection matters

Projection depth changes how far the shade line drops over the wall and glazing. A shallow overhang may cut little direct sun. A deeper overhang can protect more glass and reduce overheating. The result depends on solar altitude, façade orientation, reveal depth, and the gap above the opening.

Key inputs for better shade studies

Window height and gap above the window define the vertical distance that the shadow must cover. Overhang depth controls the primary shadow drop. Side fin depth helps evaluate side protection when sun arrives at an angle. Reveal depth reduces effective projection because recessed frames pull the shading element back from the façade edge.

How the calculation supports design decisions

The calculator estimates effective projection, shadow drop, shaded height, and width coverage. It also returns a recommended overhang depth for a chosen target shading percentage. This is useful when comparing alternate canopies, lintel projections, slab edges, or fixed louvers during early construction planning.

Practical construction use

Teams can use the output while sizing concrete projections, metal canopies, or precast shading elements. It also helps coordinate façade detailing with waterproofing, structure, and window placement. When used with local sun path data, it becomes a fast screening tool before full simulation.

Design note

This calculator uses simplified trigonometry for fast decisions. Real projects may still need climate-based daylight analysis, thermal modelling, or seasonal sun studies. Use this tool for early comparison, quick checking, and communication between design and construction teams.

Frequently Asked Questions

1) What does this calculator measure?

It estimates how far a sunshade projects, how much shadow drops over a wall opening, and how much of the window becomes shaded.

2) Why is solar altitude important?

Solar altitude controls shadow steepness. Higher altitude creates a stronger downward shadow drop. Lower altitude often needs deeper shading devices for the same window coverage.

3) What is azimuth offset?

It is the angle between the sun direction and the façade normal. Larger offsets reduce effective front projection and change the shadow pattern across the opening.

4) Why include reveal depth?

Reveal depth matters because a recessed frame reduces effective shade reach. The overhang begins farther back, so the façade receives less direct shadow projection.

5) Can I use feet instead of meters?

Yes. The calculator accepts either meters or feet. Keep all entered dimensions in the same unit system for consistent output.

6) What does required overhang mean?

It is the estimated depth needed to reach your target shading percentage under the entered sun angle, window size, and façade geometry.

7) Is this enough for final construction approval?

No. It is best for preliminary design and comparison. Final decisions should also consider local climate data, code requirements, and detailed solar analysis.

8) When should side fins be used?

Side fins help when sunlight approaches from the side. They can improve edge shading on east or west exposures where low-angle sun is harder to control.