# RF-attenuating window film

> A metallised film bonded to glazing, typically quoted at 20–35 dB, and usually the highest-value single intervention because glass is the dominant entry path for outdoor RF.

- Canonical URL: https://emfbase.com/shielding/window-film
- Collection: Shielding & remediation
- Record id: `shielding:shielding-window-film`
- Status: verified
- Last verified: 2026-08-12
- JSON: https://emfbase.com/api/shielding/window-film
- Also known as: EMF window film, metallised film, solar shielding film

## Key values

- **Form:** film
- **Targets:** radiofrequency
- **Grounding required:** No
- **Datasheet attenuation:** 20–35 dB — roughly 900 MHz – 6 GHz, datasheet values [sbm-2024]

## Failure modes

- Attenuates mobile reception inside the room as well, which is often discovered after installation
- Frame and reveal leakage limits the achievable result; film stops at the glass edge
- Some films void glazing warranties or cause thermal stress on toughened units
- Low-E glazing already provides significant attenuation, so the marginal gain can be small — measure first

## Related records

- [Macro cell tower (LTE / 5G sector antenna)](https://emfbase.com/emitters/cell-tower): Sector antennas radiate on the order of 1000 W EIRP per sector on the main beam, which is aimed above and away from the tower base — ground-level exposure directly beneath a tower is usually lower than at a few hundred metres away.
- [5G small cell / street-level node](https://emfbase.com/emitters/5g-small-cell): Pole-mounted nodes radiate roughly 10 W EIRP at street level, putting a residence 10 m away at about 8,000 µW/m² on the main beam — far below regulatory limits but often above precautionary building-biology bands.

## Sources

- `sbm-2024` Institut für Baubiologie + Nachhaltigkeit (IBN) (2024). *Building Biology Evaluation Guidelines for Sleeping Areas (SBM-2024)*. https://buildingbiology.com/site/downloads/SBM-2024_EVALUATION_GUIDELINES_EN.pdf — ngo, link checked 2026-08-12

Data licence: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Dataset version 2026.08.1. Retrieved from EMFBase, https://emfbase.com.

This record is reference data, not medical or legal advice. Regulatory limits, scientific guidelines and precautionary values are labelled separately and answer different questions.