The Heathrow expansion poses a direct threat to England's largest surviving medieval barn, the New Barn at Harmondsworth, which could be shaken to pieces by aircraft vibrations. Campaigners warn that the proposed third runway would place the 600-year-old structure in grave danger, with the public given until 1 September to submit objections. This remarkable example of medieval architecture, described by Sir John Betjeman as a 'cathedral', stands as a testament to England's rich heritage.
The Historical Significance of the New Barn
Built in 1426, the New Barn at Harmondsworth is nearly 60 metres long, 12 metres wide, and 11 metres tall, with 13 massive oak trusses supporting its roof. Its structural timbers are more than 95% original, a rarity for medieval buildings of this scale. English Heritage, which purchased the barn in 2011, considers it a masterpiece of medieval engineering and design.
Why the Barn Is Under Threat
The boundary of the extended airport would be barely a few hundred metres from the barn. Justine Bayley, English Heritage's former archaeological scientist, warns that the vibrations from airplanes taking off could literally shake the structure to pieces. Unlike many medieval buildings that have been heavily repaired, the New Barn retains almost all of its original timbers, making it exceptionally vulnerable to structural fatigue.
| Feature | New Barn at Harmondsworth | Typical Medieval Barn |
|---|---|---|
| Length | ~60 metres | 20-30 metres |
| Original Timbers | Over 95% | Often less than 50% |
| Construction Date | 1426 (exact) | Often approximate |
What You Can Do to Help
The government is currently consulting on amendments to the Heathrow expansion national policy statement. This is a critical window for public input. If you care about preserving England's medieval heritage, you can submit your objections before the 1 September deadline.
- Submit a formal objection to the Heathrow expansion consultation before 1 September.
- Share this story on social media to raise awareness.
- Contact your local MP and express your concerns about the impact on the barn.
- Support English Heritage's efforts to protect the site.
Expert Opinions and Historical Context
Justine Bayley emphasised the barn's unique status: 'It's not plus or minus 10 years or half a century. How many late medieval buildings do we know when they were built?' The land was purchased in 1391 by the bishop of Winchester, and the barn was built to store agricultural produce exactly 600 years ago. Its survival is nothing short of miraculous, and losing it would be an irreversible cultural loss.

FAQ
What is the New Barn at Harmondsworth?
The New Barn is England's largest surviving medieval timber-framed barn, built in 1426. It is nearly 60 metres long and retains over 95% of its original structural timbers, making it an exceptional example of medieval architecture.
How would Heathrow expansion affect the barn?
The proposed third runway would place the airport boundary within a few hundred metres of the barn. Vibrations from aircraft takeoffs could shake the structure to pieces, according to experts like Justine Bayley.
What can the public do to help?
The public can submit objections to the Heathrow expansion consultation before 1 September. Additionally, raising awareness and contacting local MPs can help protect this historic site.
The New Barn at Harmondsworth is not just a building; it is a link to England's medieval past. The Heathrow expansion threatens to destroy it forever. Act now to ensure this 'cathedral' of timber and history survives for future generations.