Data centre tiers explained

Data centres are the backbone of the modern digital economy. They are the physical infrastructure supporting the applications and services we rely on every day, from email and social media to e-commerce and streaming video. It is important that these data centres are designed to minimise the risk of failure and support the required levels of reliability and availability. To ensure reliability, there are different tiers and ratings for data centres, each with its own set of standards and requirements.

Data centre tiers

Let’s begin with the definition of data centre tiers. A common misunderstanding is that they are a measure of the size, capacity or maturity of a data centre. Rather, they are a measure of the level of reliability and availability that a data centre facility is designed to provide.

Tier standards are issued by various agencies. The Uptime Institute's Tier Classification System (Tier I to IV) and the ANSI/TIA-942 (Rating 1 to 4) are the most widely recognised and accepted standards for data centre tiers. The current ANSI/TIA-942-C revision was published in May 2024 and includes updates related to new technologies, sustainability and modern data centre infrastructure. Both systems define four different levels of data centres, where level 1 has the lowest level of infrastructure redundancy while level 4 has the highest level of infrastructure resilience from an infrastructure design perspective.

While both the Uptime Institute’s tier rating systems and the ANSI/TIA-942 standards are designed to classify data centre reliability and availability, they differ in their approach. The Uptime Institute (UTI) primarily focuses on the design of mechanical and electrical critical infrastructure. The ANSI/TIA-942 standard covers a wider range of aspects related to data centres, including not only the design, mechanical, and electrical critical infrastructure but also the network, architectural, and operational considerations. This means that the standard incorporates other important areas such as security, architecture, and telecommunications.

The two standards share a common ground despite their differences. Initially, the Telecommunication Industry Association (TIA) released TIA-942, in partnership with the American National Standards Institute (ANSI), using the same tier levels. However, this led to confusion, prompting TIA to revise their tier levels to rating levels.

In this blog post, we'll discuss the specific requirements for your data centre by examining the various tier levels according to the Uptime Institute. So, what exactly are these tier levels? Read on to find out.

Uptime Institute Tier Standard Topology (TST)

To get a quick overview of the differences between the Tier Standard Topology, a summarising overview can be found below. For a more comprehensive understanding of each tier level, we'll provide a short clarification of each Tier level.

Certification

To achieve certification for your new data centre, whether it is TIA-942 or Uptime certification, your data centre needs to be designed and constructed according to the chosen standards. Depending on the certification scheme, certification can apply to design documentation, the constructed facility and/or operational sustainability.

In addition, policies, procedures and operations need to be in place to reduce downtime risks as well. If your data centre has been designed and constructed to the standards, but operational policies and procedures like disaster recovery or maintenance and testing are not in place, you may not achieve your availability targets.

Accredited designers and specialists

When it comes to building or upgrading a data centre, considering your organisation’s specific requirements is essential to determine the appropriate tier. What type of applications and services will be hosted in the data centre?

With our Tier and TIA-942 accredited designers and specialists, Haskoning can help you to translate your availability and reliability requirements into the design of your new data centre. We understand that a data centre is a critical component of your organisation's IT infrastructure and downtime can result in significant financial losses. That's why we are proud to offer accredited designers and specialists that have demonstrated their expertise in designing and delivering data centres that meet the highest industry standards for availability and reliability.

Equipped with the latest knowledge and tools, we can help you design a data centre that meets your specific needs and budget. Working with you to assess your requirements, conduct site analysis and recommend the right design and infrastructure to meet your objectives. We will also ensure that your data centre meets all relevant regulations and standards and provides a safe and secure environment for your IT equipment.

With Haskoning's Accredited Tier and TIA-942 Designers and Specialists, you can be confident that your data centre will meet your availability and reliability requirements. Contact us today to schedule a consultation and learn how our team can help you design a data centre that meets your needs.