| Clue | Source | Date |
|---|---|---|
| Window only 75% of the specified weight? | The Telegraph Toughie | 10 Jan 2025 |
| Fourth window? (12) | ||
| Only a fourth the illumination from the ventilation window (7,5) | ||
| Fourth lamp in window (12) | ||
| Small window 75 per cent dark? | The Times Cryptic | 18 Apr 2022 |
| A fourth window? | The Telegraph Cryptic | 09 Feb 2019 |