Manchester United is facing a big decision on what to do about its ageing Old Trafford stadium. As it considers whether to rebuild or refurbish, here is a guide to how six other major sports stadium projects fared

While Manchester United had been having a tough time on the pitch, the club also faces a dilemma off it as it considers what to do about its outdated, if iconic, stadium.

See also>> To refurb or rebuild: what next for Old Trafford?

Below is a brief guide to how six other major sports stadium projects in the UK fared, including how long they took to build, who the contractors were and by how much costs overran.

Principality Stadium, Cardiff (formerly Millennium Stadium)   

principality stadium

Capacity  74,500

Completion  1999 

Planned cost £106m

Final cost £152m

How much it increased  43%

Time to build  Two years (1997-99)

Main contractor  Laing Construction

Etihad Stadium, Manchester (formerly City of Manchester Stadium)

etihad stadium

Capacity  38,000 as an athletics arena, 48,000 after conversion, then upgraded to 55,097

Completion  2002 (build); 2003 (conversion)

Planned cost £90m (build); £40m (conversion)

Final cost £112m (build); £42m (conversion)

How much it increased  24% (build), 5% (conversion)

How long to build  Three years (stadium build: 1999-2002); one year (conversion: 2002-03)

Main contractor  Laing Construction (athletics stadium build and conversion) 

Emirates Stadium, Arsenal

emirates stadium

Capacity   60,000

Initial deadline   2004 

Actual completion   2006

Planned cost  £100m

Final cost  £390m

How much it increased   290%

How long to build   Three years (2003-06)

Main contractor   Sir Robert McAlpine

 Wembley Stadium

wembley stadium

Capacity   90,000

Initial deadline   2003

Actual completion   2007

Planned cost  £458m

Final cost  £798m

How much it increased   74%

How long to build   Four years (2003-07)

Main contractor   Multiplex 

London Stadium, Stratford (formerly Olympic Stadium)

london stadium

Capacity  60,000, reduced from 80,000 following Olympic Games

Completed on time   2012 (Olympic stadium), 2016 (conversion)

Planned cost £496m (build), £100m (conversion)

Final cost £547m (build), £323m (conversion)

How much it increased  10% (build), 223% (conversion)

How long to build  Four years (2008-12 build), three  years (2013-16-conversion)

Main contractors  Sir Robert McAlpine (build), Balfour Beatty (conversion)

 Tottenham Hotspur Stadium

tottenham hotspur stadium

Capacity  62,850

Original deadline  September 2018

Actual completion  April 2019

Planned cost £380m

Final cost  Up to £1bn

How much it increased  Up to 160%

How long to build  Three years (2016-19)

Main contractor  Mace