30 St Mary Axe (The Gherkin), London: a double-glazed facade wrapped around a curved tower.

Reference project — not a Eurowindow project. This article summarises public information from the sources listed at the end, with our own commentary. Images belong to their owners and are embedded directly from Pinterest with a link back to the source.

The project at a glance

• Name: 30 St Mary Axe (The Gherkin), City of London, UK
• Architects/engineers: Foster + Partners (architect); Arup (structural); Skanska (main contractor) (per Wikipedia)
• Scale: 180 m (591 ft) high, 41 floors, 64,470 m² floor area (per Wikipedia)
• Timeline: Construction began 2001; completed December 2003; opened 28 April 2004 (per Wikipedia)
• Facade: A double-glazing effect with air between two layers; Arup’s fully triangulated perimeter structure keeps the tower rigid without extra reinforcement; only one piece of curved glass, the lens-shaped cap at the apex (per Wikipedia)
• Ventilation: Gaps in each floor form six shafts for natural ventilation, with firebreaks every sixth floor (per Wikipedia)
• Cost/awards: £138 million (plus £90.6 million for the land); 2003 Emporis Skyscraper Award; 2004 Stirling Prize (per Wikipedia)

What stands out in the facade

According to Wikipedia, the tower was designed by Foster + Partners with Arup as structural engineer; it is 180 m high with 41 floors and opened on 28 April 2004. The facade gives a double-glazing effect with air between two layers, and Arup’s fully triangulated perimeter structure makes the building rigid without extra reinforcement. The tower has just one piece of curved glass — the lens-shaped cap at the top.

Gaps in each floor form six shafts for natural ventilation, with firebreaks on every sixth floor. Wikipedia also notes that after a glass panel fell in 2005, engineers re-examined the other 744 glass panels.

Note: the Wikipedia article does not give a total glass area; we quote only what could be read.

Our take

From a bullet-shaped tower in London, three lessons for curtain walls:

1. A facade can be part of the ventilation strategy, not just weather protection. When glass is split into two layers, the air gap does real work in the building’s performance. See Eurowindow curtain walls.
2. Curved geometry needs very little curved glass if the framing is divided sensibly. Fewer curved panes helps control glass cost and production schedule.
3. After a panel fell, inspecting all the remaining panels became the necessary process. Facade maintenance files should include a periodic inspection plan from the start.

If you are weighing options for a high-rise project, send your brief to the Eurowindow technical team to discuss specifics.

Sources

• Wikipedia — 30 St Mary Axe
• Archinomy — Case study: 30 St Mary Axe
• Pinterest — pin: Archinomy – pin reference

This article is for reference only and does not imply Eurowindow took part in this project. If you own an image or content and would like it changed or removed, please contact sonhn@eurowindow.biz; we will act immediately.