The light at the end of the tunnel

Idom is about to commence the final phase of work for the Arriyadh Development Authority (ADA) on the development of the metro system in Riyadh, Saudi Arabia.
We were appointed as lead designer on the project in 2014. The modernisation of the metro system is part of the Riyadh Public Transport Project (RPTP), Saudi’s largest public transport initiative comprising the construction of a metro network, a bus system and other transport services in the capital.

Riyadh’s population is expected to increase to eight million by 2030. The new metro system has been designed to fulfill the demands of an ever-growing population; it will also create 15,000 local jobs, as well as reduce traffic congestion and improve air quality in the city.

The new metro system is expected to be completed by 2018 and will be 178km-long with six lines and 85 stations, which includes underground, elevated and at-grade sections.
As part of the consortium led by Salini-Impregilo, Idom has been responsible for the system’s entire design including route, tunnel, viaducts and level sections, along with the underground and over ground stations, workshops, sheds, road network and the landscape works necessary for repositioning and blending in with the urban environment.

Sustainability is at the heart of the project and energy saving techniques have been designed throughout all phases. The extreme desert climate and high solar radiation where temperatures can soar to 50º C have been an engineering challenge and the main strategy has been to reduce energy consumption within the architectural design, producing buildings with an envelope based on bioclimatic concepts.

As such, buildings have been created to minimise energy consumption and low environmental impact materials have been used during construction. To help reduce water consumption grey water has been treated and recycled for irrigation.

Additionally, the design of the Metro’s roof has been engineered to reduce direct solar radiation while maximising the use of natural light. This has been achieved by introducing north-facing skylights, while at the same time optimising the positioning of photovoltaic panels, which generate 45% of the electricity consumed by the fixed equipment of the building.

Nigel Huish, Managing Director, Idom Merebrook commented:

“The Riyadh Metro project is a great showcase of Idom’s multi-disciplinary capabilities, the project has been ambitious in terms of rail design and build and the extreme desert conditions have presented some very unique architecture and design challenges.

While the stations are based on a predefined design, Idom has had great freedom to develop the work on many levels and has prioritised the sustainability of the system giving it a high level of energy efficiency, from the shading of the buildings to the design of a high performance envelope or optimising the installation of solar panels, air-conditioning systems and energy–efficient lighting.”