A sunlight study you make yourself.
Enter an address and watch the sun cross the plot in 3D. Sketch the building plan, compare before and after, and run the TNO standard. Exploring costs nothing; the report costs €49.
Free to explore. Pay €49 only when you download the report.
In short
What is a sunlight study?
A sunlight study calculates, in a 3D model, how many hours of direct sun a window, façade, garden or terrace receives, and how much of that a new or planned structure takes away. In the Netherlands the outcome is assessed against the TNO standard: the light variant requires at least 2 hours of sun per day between 19 February and 21 October, the strict variant 3 hours between 21 January and 22 November. Municipalities ask for such a study with a permit application; residents use it to support a formal view, an objection or a neighbour-law dispute.
Four words, one thing
Sunlight study, sunlight assessment, shadow study.
The Dutch market uses these terms interchangeably. They refer to the same calculation; only the emphasis differs.
| Term | What is meant by it |
|---|---|
| Bezonningsstudie | The common name for the whole analysis: sun hours per measurement point, before and after the plan. |
| Bezonningsonderzoek | The same thing, usually used for the formal report that goes into a case file. |
| Schaduwstudie | The same calculation seen from the other side: where the shadow falls rather than where the sun reaches. |
| Bezonningsdiagram | One component of the study: the drawing that shows the shadow per reference day and time. |
Schaduwplan delivers them in one report: sun hours per measurement point, the diagrams per reference day, and the verdict per standard. More about the formal sunlight assessment.
Free or paid
Can a sunlight study be free?
The calculation can; the piece of evidence cannot. With Schaduwplan you explore for free and without an account: enter the address, inspect the 3D model, sketch the building plan, place measurement points and read the TNO verdict off the screen. That is enough to know where you stand. To put it on record — with a north arrow, scale bar, source references, methodology and a verifiable report ID — costs €49 once. You see a four-page preview of your own report first and pay afterwards.
- Free: 3D model, sketching the plan, measurement points, TNO verdict on screen
- Free: as many addresses and scenarios as you like, without an account
- €49: the PDF with source references, methodology and report ID
- €49: the shareable link to the 3D scene that belongs to the report
How it works
From address to study in three steps.
Nothing to install, nothing to draw in CAD. It all runs in your browser.
- 01
Enter the address
The 3D model of the house and every surrounding building is ready in seconds, straight from 3DBAG and AHN. No upload, no drafting.
- 02
Sketch the plan and place measurement points
Draw the extension, roof addition, dormer, fence or tree in question. Mark the windows and garden positions that lose sun and compare before and after.
- 03
Read the verdict, download the report
Sun hours per measurement point and the verdict per standard appear on screen immediately. If the picture is right, you download the PDF.
What a consultancy does not hand over
The report links back to the scene itself.
A consultancy's sunlight study ends as a PDF with a handful of fixed snapshots. The official or judge reading it sees only the days and times somebody else selected, and has to assume the rest holds. Every Schaduwplan report carries a link to the 3D scene it was made from. Open that link and you rotate the model, look from any point, and push the sun through every day of the year. Same geometry, same data, nothing pre-selected.
The link works without an account and without installing anything, even for someone who has never used Schaduwplan.
Cost
What does a sunlight study cost?
At a consultancy a sunlight study usually costs €330 to €535 per report, delivered in 5 to 10 working days. At Schaduwplan you pay €49 once per report, VAT included and without a subscription. Exploring and calculating is free; you pay at the moment you download the report.
Consultancy rates based on a public rate overview from three Dutch consultancies (enquiry 15 Apr 2026).
Possibly covered by your home legal-expenses insurance.
Home legal-expenses insurance can cover sunlight reports in disputes about building permits or neighbour law. Check your policy for "deskundigenrapport" (expert report) or "bouwtechnisch advies" (technical building advice) — or email us and we will help.
How do I submit this to my insurer? →€49 one-time
For one address, one decision — objection, permit, purchase or design.
- TNO light + strict standard
- Municipal standards where applicable
- Before/after comparison existing vs. planned
- Shareable link to the 3D scene
- 3 measurement points included (+€5 per extra point)
See a free four-page preview of your own report — pay only when it is right.
Frequently asked questions