50 window & door facts (to celebrate our 50th birthday!)

Having been in business for the last 50 years, delivering premium home improvements products is firmly rooted in our DNA. With this in mind, we’ve come up with 50 interesting facts about windows and doors that we’d like to share with you.

  1. 1. Before glass was used for windows, ancient window materials included parchment, flattened animal horn, paper and thin sheets of naturally occurring minerals such as mica and marble.
  2. 2. Around the 1st Century, the Romans are believed to have been the first to use glass to create windows.
  3. 3. At 2,716 feet tall, Dubai’s impressive Burj Khalifa skyscraper is the tallest building in the world. Featuring 24,348 windows, totalling 1,290,000 sq. ft. of glass, it takes a team of 36 window cleaners 3 months to clean every single one of its windows!
  4. 4. The fastest window cleaner in the world was recorded in Blackpool, England, cleaning three standard office windows in 9.14 seconds.
  5. 5. Glass is created from liquid sand, limestone and soda ash.
  6. 6. The largest pane of glass in the world is an 8-metre mirror that large astronomical observatories use to research the universe.
  7. 7. 'Broadsheet' glass was a form of hand-blown glass that was first produced in Sussex, England, in 1226.
  8. 8. The largest doors in the world provide entry to NASA’s Vehicle Assembly Building at the Kennedy Space Centre on Merritt Island in Florida. Made from bulletproof steel, they’re 456 feet high and take around 45 minutes to fully open or close!
  9. 9. Glass is 100% recyclable, able to be reused over and over again without losing quality.
  10. 10. The oldest door found in Europe is believed to be 5,100 years old, discovered in 2010 by archaeologists in Zurich who were excavating a car park.
  11. 11. The Roman God of beginnings, endings, doors and transitions was known as Janus. So, to honour and welcome him in, the Romans built their doors to swing inwards. With this in mind, January was also named after Janus; to symbolise the first month of beginnings and openings.
  12. 12. Chemicals are added to make coloured glass, e.g. Cobalt Oxide creates blue-violet glass, Gold Chloride is red and Chromic Oxide is emerald green.
  13. 13. The largest curved glass panels in the world can be found at Apple HQ in Cupertino California, where the largest panel measures a whopping 47 ft by 10.5 ft.
  14. 14. Following developments in glass making techniques, in the late 16th Century English glassmaker George Ravenscroft patented a formula for lead glass; heavy, clear glass that could be cut into small diamond-shapes and held together with leaded lights.
  15. 15. The first window glass manufactured in Britain was in the early 17th.
  16. 16. Britain’s oldest door is a historic oak door, thought to be 900 years old. It was identified in 2005 by archaeologists at Westminster Abbey.
  17. 17. Although widely contested, it appears that the south rose window at Notre Dame cathedral in Paris holds the record for the world’s biggest window. With an astounding 12.9 metre diameter and 84 panes of glass, how long do you think it would take to clean?!
  18. 18. In 1696, a ‘Window Tax’ came into force in England and Wales which was based on the number of windows in a house. Repealed 156 years later in 1851, this is why some older buildings have bricked-up windows.
  19. 19. The oldest windows in the world are believed to be in a cathedral in one of Germany’s oldest cities, Augsburg in Bavaria, founded by the Romans in the 1st Century.
  20. 20. The first insulating glass unit was patented in 1865 by Thomas D. Stetson, but the first patent for a double-glazed unit wasn’t lodged until the 1930s in the US.
  21. 21. Britain’s oldest working window frame is thought to date back to pre-1066, located at St Andrew’s Church in the village of Boxford in Berkshire.
  22. 22. Inefficient windows and doors cost UK homeowners over 25% of their energy bills.
  23. 23. Upgrading windows and doors from single to double glazing can reduce household energy bills by up to £110 per year.
  24. 24. The smallest window in the world is thought to be in Kingston-upon-Hull in East Yorkshire. It consists of a 10” x 1” narrow slit that the Hotel gatekeeper used to keep a lookout for stagecoaches and customers.
  25. 25. The ‘float glass’ method that we use to make glass for windows and doors today was successfully invented by Sir Alastair Pilkington in 1959.
  26. 26. uPVC was first produced in 1935, but the first uPVC windows and doors weren’t introduced to the UK until the 1980s via Germany.
  27. 27. Research released in 2019 by Rentokil Property Care found that 5.8 million British renters had experienced damp and condensation issues. Simple lifestyle changes such as leaving windows ajar can reduce such issues.
  28. 28. Upgrading windows and doors to triple glazing can save up to £766 per year on household energy bills.
  29. 29. The UK’s flat glass manufacturing total revenue in 2019 was £310m.
  30. 30. There are 4 main glass types or strengths of glass used in windows and doors; annealed glass, heat-strengthened glass, toughened glass and laminated glass.
  31. 31. 5% of burglaries take place due to a door being left unlocked.
  32. 32. The world’s largest pivoting window can be found in a renovated home in Antwerp in Belgium. Weighing almost 4 tonnes, its 6 metres high and 3 metres wide.
  33. 33. Enhancing your home's exterior has the power to boost your property value by up to 10%.
  34. 34. If windows become ‘misted’ in between the panes of glass, this is a sign that your window seals have failed and need replacing.
  35. 35. The average lifespan of a wooden door is at least 30 years.
  36. 36. The aluminium windows of today are incredibly energy efficient in comparison to their historical counterparts. This is thanks to the inclusion of innovative thermal break barriers that are placed between the inner and outer frame, effectively preventing heat from escaping.
  37. 37. The most popular door colour in 2018 was mid purple, closely followed by steel blue hues (blue/grey colours).
  38. 38. Considering that recycling one tonne of aluminium saves the carbon dioxide emissions of driving nearly 27,000 miles, whilst recycling just one aluminium can save enough energy to run a TV for three hours, aluminium windows and doors are the most sustainable home improvement option around.
  39. 39. The world’s largest window in space can be found in the International Space Station’s 7 window ‘Cupola’ observatory, boasting an overall diameter of 2.95m and 1.5’s high. Each window is made from 4 panes of glass that are between 0.5 and 1.25 inches thick.
  40. 40. Aluminium windows and doors are 3½ times stronger than uPVC and 40 times stronger than timber.
  41. 41. Built-in 1969, the largest stained-glass window in the world is over 22,000 square feet, located in The Resurrection Cemetery in Justice in Illinois.
  42. 42. The average lifespan of a composite door is at least 30 years.
  43. 43. China’s Chimelong Ocean Kingdom theme park features the world’s biggest aquarium window, measuring an amazing 39.6m x 8.3m.
  44. 44. The average lifespan of uPVC windows and doors is around 20-30 years.
  45. 45. The world’s tallest revolving door can be found in the Novotel Citygate Honk Kong hotel, measuring 4.8m (15ft 9in).
  46. 46. The average lifespan of aluminium windows and doors is at least 45 years.
  47. 47. uPVC windows and doors can be recycled up to 10 times without impacting on material performance.
  48. 48. Argon gas is used to fill the gaps between double and triple glazed windows and doors as it is denser and has 34% lower thermal conductivity than air, effectively slowing the air from circulating.
  49. 49. Have you ever wondered why many church doors are painted red? The symbolism of red doors was a way to remember the sacrifice that martyrs made for their faith, as well as a symbol of sanctuary, refuge and safety.
  50. 50. In total, Buckingham Palace features 760 windows and 1,514 doors.

If you’re planning a renovation but don’t understand some of the terms being used, you may find it useful to take a look at our helpful home improvement glossary. Need further guidance? Don’t hesitate to get in touch with an SEH BAC expert for all your restoration needs.

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