Civil Aviation Authority (CAA) and Birmingham City Council’s own ‘High Places’ planning policy framework restricted new buildings to a maximum height of around 120 metres, stymieing a number of appreciably taller proposals. These included the 245-metre Arena Central Tower, which at the time was set to become the tallest skyscraper in the United Kingdom. A number of subsequent proposals, including revised plans for a 152-metre V-shaped building at Arena Central, the 201-metre Regal Tower, and the 130-metre twin towers proposed for the New Street Station Gateway Plus project, succumbed to the global financial crisis and were either scaled back or scrapped. Consequently, Birmingham’s most iconic 21st century buildings, including the Selfridges Building, Grand Central Station and the Library of Birmingham, are under 100 metres tall. Present and future developments In recent years the City Council has sought to encourage large-scale development, and a raft of tall buildings have been approved for construction across the City Core and all six of Birmingham’s City Centre Quarters – Eastside, Digbeth, Westside and Ladywood, Southside and Highgate, the Jewellery Quarter and St George and St Chad. These developments include the first three skyscrapers in Birmingham and will form a number of tall clusters across the city centre. Already home to some of Birmingham's tallest buildings, the City Core will see several tall developments in the coming years, including the 155-metre Octagon tower at the Paradise redevelopment site in the city's Civic Heart, which is currently under construction. When completed, Octagon will become the world's tallest octagonally-shaped residential building. Octagon will be near neighbour to the newly completed 103 Colmore Row (108 metres), which is the tallest dedicated office building to be constructed outside of London since Alpha Tower was completed in 1973. To the east of the Historic Colmore Business District, Birmingham's Retail Core is set to be reshaped by Hammerson’s mixed-use Martineau Galleries scheme, incorporating a third building in excess of 100 metres in height. In Westside and Ladywood, Moda Living’s 132-metre Mercian residential tower was completed in 2022 and became the tallest habitable building in Birmingham. It could be surpassed by the 193-metre 100 Broad Street residential skyscraper which, if built, would become the second tallest regional building in the United Kingdom. However, the viability of this project is currently unclear. Other significant residential schemes around Broad Street and Brindleyplace include 111-metre Cortland Broad Street and 102-metre Bank Tower II, while Axis