ME Engineers inside look into Climate Pledge Arena


ME Engineers at Coliseum US Image: Climate Pledge Arena & ME Engineers

The 17,459-capacity Climate Pledge Arena is a multipurpose arena in the Northwest United States in Seattle. It is located north of downtown in the 74-acre entertainment complex known as Seattle Center, the site of the 1962 World’s Fair. The renovated building opened on October 19th, 2021.

Climate Pledge Arena is the home ice of the Seattle Kraken, a professional ice hockey team based in Seattle, Washington, U.S. The Kraken compete in the National Hockey League (NHL) as a member of the Pacific Division in the Western Conference and began play during the league’s 2021-2022 seasons.

ME Engineers is a mechanical, electrical, plumbing and technology design firm with 14 offices throughout the world, including offices in London, New York, Los Angeles, Doha, Chennai, and its headquarters in Denver, Colorado. ME Engineers designs building systems for the sports world and has completed over 300 sports facilities projects, including 70 arenas + 16 National Hockey League (NHL) arenas under its wings.

In an exclusive talk with ‘Coliseum’, Jeff Sawarynski, Senior Principal and mechanical engineer, George Reiher, Senior Principal and electrical engineer, and Mohit Mehta, Principal and Building Performance Director, shared how they took up the gauntlet of helping build the net zero Climate Pledge Arena – one of the most sustainable arenas in the world and the most complicated project in North America.

This complex project leaves the iconic roof and building façade intact while completely renovating the interior spaces, giving the highest priority to the sustainability quotient.

Climate Pledge Arena Key Facts

  • 1962 historic landmark renovation;
  • 800,000 square feet;
  • The first certified zero carbon arena in the world;
  • Capacity – 17,100 seats;
  • NHL arena also used for basketball and concerts; and
  • Opened in October 2021.


Complex complexity

In 1962, the Climate Pledge Arena was part of the World’s Fair in Seattle where they would showcase futuristic cars and other elements. The arena stands out for its roof architecture and the single pane that wraps it.

Jeff Sawarynski, the lead mechanical engineer for the project, says“It is important to know is that when the ownership group decided to build a carbon-neutral building and the world’s greenest arena, the focus shifted to not only LEED certification but carbon neutrality,, which is doubly challenging. Seattle has a very clean energy grid but it was going to require an owner who was willing to pay more money upfront and in the long-term operating costs of the building to create that carbon-neutral environment.”

LEED-certified stadiums are not only promoting sustainable construction methods and materials, but also showing just how far LEED can be taken with existing buildings through the integration of renewable energy sources, better waste management and recycling solutions, and even food donations and educational programs.

LEED (Leadership in Energy and Environmental Design) is an ecology-oriented building certification program run under the auspices of the U.S. Green Building Council (USGBC).

Challenges galore


Mechanical systems

  • Heating system;
  • Dehumidification; and
  • “Rain to Rink“ system for the ice rink

Sawarynski added “Basically, the entire building systems shifted from natural gas to all electric in a relatively clean grid in Seattle with hydro power that offset electrical consumption with renewable sources. In addition, our dehumidification system was critical to the functionality of the building as an NHL venue, as well as water conservation from the “Rain to Rink” system, which utilized rainwater to create the ice for the hockey rink.

Heating system:

  • All electric; and
  • Domestic hot water.

The biggest challenge ME Engineers faced was to suddenly transform the building to electricity mode and a decision to this effect was made in the Summer of 2020 – “By that time, the building was already under construction, several components were already in place, says Sawarynski.

Dehumidification system

The dehumidification system uses high temperature gas-fired air while maintaining strict requirements laid down for an NHL venue.

With its incessant rains the climate in Seattle favored a “Rain to Rink” ice system.

Informed Sawarynski, “The whole process of collecting rainwater, filtrating and storing it and then adding it to the ice rink was quite a complicated process. This system will save tens of thousands of gallons of water every NHL season.”

Electrical engineer George Reiher took up from Sawarynski and explained about the electrical systems of the ‘green’ venue.

Electrical systems

  • Medium voltage distribution
    • Dual feeds from Seattle City Light;
    • 26KV distribution voltage; and
    • Inherent capacity.
  • Generator
    • 4,160V
    • 3.3MW

Stated Reiher, “With an electric building, it goes without saying that electricity is very important. Seattle City Light (the public utility providing electricity to Seattle) was servicing the building prior to it becoming all-electric. Their distribution voltage is 15 KV and when Climate Pledge Arena was modified into an electric building, the Seattle City Light delivered 26 KV. That 26 KV inherent capacity on this system helped us in realizing an all-electric arena.”

Added Reiher, “We have brought the 26 KV into the building and we are distributing all the way below and in the sides, distributing 26 KV into four quartets and then up to the building. What’s interesting is that when it was decided that Climate Pledge Arena will go all-electric, all our loads ended up being in one location and that was near the parking lot – the only location where we could actually put all this new equipment to handle the distribution. So, we were lucky from that standpoint that we didn’t have to affect distribution downstream that would have caused further delays to the project.”


The substations were taking 26 KV and distributing it down the 4AD – typical arenas, with six substations to accommodate the required electricity needed for the boiler plant to handle both the heating hot water and domestic hot water, and as well as the kitchen.

ME Engineer’s Sustainability Director Mohit Mehta joined Sawarynski and Reiher to discuss the sustainability aspects of the project.



Operational energy

Informed Mehta, “With Climate Pledge Arena we had to accomplish two main goals – not just the operational carbon but we also had to meet the Paris Agreement goals. During the construction stage, it became clear that to make this a truly sustainable building we couldn’t just focus on this one sports project, but all sports projects going forward. You have to focus not just on the operational piece, but the embodied carbon, which is just as impactful. So, we focused on both these areas for this project, which was a huge challenge for us.”


  • Conserving historic roofline reduces embodied energy;
  • Conversion to 100 percent electric/no fossil fuel consumption;
  • 100 percent renewable energy;
  • Zero waste; and
  • Rainwater harvesting and reuse.

Another big challenge faced by ME Engineers was the historic roof. “It wasn’t just that the existing roof had to stay in place, the existing façade with the single pane glass also had to stay in place. There was no way we could find an insulated glazing unit framing system that looked like the existing façade and keep its pristine sheen intact, so we had to stay with the existing glass. We had to overcome all of those challenges while being energy code compliant.”

But, keeping the roof and the façade intact while getting converted to 100 percent electric is no mean task as Mehta pointed out, “In fact, the Climate Pledge Arena might be the first building where all food service and all cooking is all electric. Of course, we put as much renewable energy as we could into the project and not just in the venue’s historic roof but also for other buildings that are part of the complex. The main pivot of this project is on zero waste.”

Complex energy code

  • Competing goals
    • Energy
    • Carbon

The energy codes for the city of Seattle and the state of Washington are already some of the most stringent in the country. Says Mohit, “You have to remember that all these cities and all these states are going towards banning gas because you do not want to use fossil fuel and the grid is getting cleaner, and the way they make electricity is getting cleaner and only getting better. At the same time you have to work within the area’s energy code with a new electric target on all these projects, as well as work within the LEED certification process.”

Energy code

  • How to divide the building?
  • Model the building as a whole?

Mehta stated that another challenge facing the team was during the energy modeling of the project. “How do we divide this building? Should we model it as one whole building because there are different modeling rules for existing buildings and new buildings. The energy modeling effort was complex. We had to follow a flow chart with the code authorities in town to satisfy LEED, carbon, energy goals, etc. So, it was quite a fun ride full of challenges at every turn.”

Carbon challenge

The zero carbon part of the Climate Pledge Arena is where the rubber meets the road as Mehta pointed out, “Essentially, the carbon impact, if you adjust on a high efficiency LEED project, you would be responsible for about 43 metric tonnes of carbon emissions over 30 years of this building. By going all electric, we have eliminated all a huge carbon impact. We are down to only 16,000 metric tonnes over the life of the building, which is a 61 percent reduction in operational carbon and that is being offset by some off-site photovoltaics. So, that was a big win for us.”

Just to close it out, Mehta mentioned that the Climate Pledge Arena has photovoltaics on as many roofs as possible, lot of water conservation measures and the “Rain to Rink” ice system as well.

  • Net zero carbon (gas to electric);
  • Photovoltaics (100 percent);
  • Rain to Rink System (make ice); and
  • Conserve water (waterless urinals).

A big shout-out to the ME Engineers team for pulling off so successfully a very complicated development like the $ 1.15-billion arena project – Climate Pledge Arena – which is powered entirely by renewable energy. ME Engineers, along with the ownership group and the entire design and construction team of Climate Pledge Arena have brought to fore their environmental responsibility and have given the world an environmental beacon of change.

Finishing on time bears testimony to the sustained collaboration and teamwork of the designers, builders and engineers. The result is one of the most sustainable sports venues on the planet – Climate Pledge Arena – and the ME Engineers have indeed stood the test of time with this project.

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