As architects and designers work to meet housing need in urban areas, there is an ever-increasing shift to building upwards rather than outwards. This trend is rapidly changing city skylines across the country.

Nowhere is this more true than in England’s second city where The Octagon by architect Howells is the world’s first purely octagonal residential high-rise building and has taken the crown of Birmingham’s tallest building. Standing at 155m tall, the 49-storey skyscraper consists of 370 build-to-rent homes.

The £110m project which was completed in September 2025 is part of the wider Paradise development, a large mixed-use regeneration scheme in the centre of the city.

Midgard, part of JRL, who were the main contractor for the project employed Modern Methods of Construction (MMC) throughout the building design. The Octagon’s façade and structural elements including the walls, floor slabs and columns are all made from precast concrete.

Precast concrete offers high levels of structural integrity, durability and fire resistance, essential qualities to the design of safe, high-quality housing. When building at such height, precast concrete is a highly efficient construction method which enables a faster build and repeatable design.

The precast concrete components were manufactured locally in the West Midlands before being transported a relatively short distance to the project site. For urban projects such as this which have tight spatial constraints, the just-in-time delivery reduces the need and cost to store the concrete elements on site.

Different concrete mixes containing varying levels of ground granulated blast furnace slag (GGBS) were used for The Octagon’s bindings, walls and columns. Using a higher proportion of supplementary cementitious materials helped to reduce the carbon content of the concrete whilst maintaining the same structural integrity.

A distinct addition to the Birmingham skyline, The Octagon demonstrates the opportunities available for high rise construction using concrete to build safe, durable, low-carbon housing.