It was crucial that the project was completed within the specified timeframe and so a modular construction technique was the preferred option. The design and specification of the buildings also had to incorporate a variety of environmentally friendly materials, aligning with the project's strong Environmental, Social, and Governance (ESG) credentials.

There was a requirement for a quick, convenient and recyclable connection from one side of the modular units to ensure increased speed of installation while maintaining environmental and sustainability standards.

Using the most advanced modular 3D technology, 257 modular units were to be manufactured offsite in Poland and transported to the construction site in Edinburgh. Hollo-Bolt, the original expansion bolt from Lindapter was specified for connecting the modules together onsite, using pre-drilled steel plates and angle brackets, due to its versatility including speed of installation from one side and its design for de-construction credentials.

Installation was quick and easy, each modular unit was lifted by crane and carefully stacked on top of each other and connected using Hollo-Bolts inserted through the steel plates and angle brackets into pre-drilled holes of the modular units. Each Hollo-Bolt was installed using a torque wrench to provide the necessary clamping force.

Countersunk head Hollo-Bolts, size M16 were used on the bracket interface between the steel modular units and concrete lift core, while Hexagonal Head Hollo-Bolts, size M20 were used in conjunction with pre-drilled plates to fix modules in the vertical plane. Additionally, countersunk head Hollo-Bolts, were selected to secure horizontal floor plates to attach the modules horizontally with minimal bolt head protrusion.

Hollo-Bolts along with the modular construction technique facilitated the fast construction of the first five-storey student accommodation building allowing the project to be completed on time.

The widespread adoption of Hollo-Bolt for connecting modular buildings demonstrates how Lindapter's expansion bolt streamlines construction by eliminating the necessity for labour-intensive and costly on-site processes like welding, cutting, or through-bolting.

• Fast, convenient installation from one side
• Safer installation as no hot works required
• No specialist equipment required to install
• Unique high clamping force design