Comcast Corp.'s new tower will open later this year, a $1.5 billion steel-and-glass wonder with no private offices, no desk phones, and 300 meeting rooms linked by a scheduling app.

But the tower's first incarnation has been in a more prosaic place: a former suburban office complex 30 minutes from Center City, in Horsham, that Comcast and its consultants redid to replicate a floor in the new building.

Called the "mock-up," the high-ceilinged suburban office has panoramic photos of Philadelphia glued onto the walls, a mind-bending detail so Comcast employees think they are really in the tower's 36th floor when they visit.

The goal is to find the layout that fuels the most creativity and collaboration. Comcast has cycled more than 1,000 employees from eight divisions through the site, surveying their reactions and observing how they interact in the so-called open floors where everyone sits together without private offices.

While popular for at least a decade now at such companies as Facebook in Silicon Valley and Curalate in Philadelphia, open floors also have been criticized as distracting and stressful for employees who need some privacy to think and create. The trick is to make the new expensive tower both fun for employees and productive for the company.

"We have tried to create a good section of the workplace to see how it really functions," Rebecca Humphrey, managing principal with Comcast consultant Focal Point, said during a visit. "How it looks. What it sounds like. How people really move through the space."

Some Comcast employee groups even worked at the mock-up for a day for real-time feedback.

Sensitive to employee concerns, Comcast has sought to carve out different settings in the floors of the new Comcast Technology Center. Some areas will be like libraries or quiet-ride train cars. Others will bustle with a Starbucks coffee shop vibe — or should.

Employees developing advances on the X1 set-top box, Wifi and mobility products are expected to find niches and use them. Employees will have sit-and-stand desks.

The Horsham mock-up itself, off Blair Mill Road, opens to a seating area with white plastic chairs for presentations and models of the new 60-story tower. When you walk up a ramp, you come eye-to-eye with Billy Penn on City Hall.

Karen Buchholz, senior vice president for administration who is tasked with making the new tower a success, said "the more information we can give people, the better experience it will be for everyone. We need it to be easy for employees to feel at home."

Comcast CEO Brian Roberts has visited, assessing the new tower's look and feel. On one visit with the tower's London-based architect, Norman Foster, they agreed to put yellow, orange, red, blue and purple color in the ceilings along the corridors to make it warmer.

The cable giant would like to ease the transition for the 4,000 employees who will work there, appointing 107 "change ambassadors" who are informed on the new building and its progress. There is a dedicated Slack channel for them. Most of these employees will be relocating from across the street, where Comcast leases multiple floors in the former Bell Atlantic building.

According to a survey last year by the staffing firm Robert Half, open-floor structures can lead to collaboration, but they also can induce stress. "Some people thrive in an environment where there is more activity going on around them," Stephanie Naznitsky, Philadelphia-area regional vice president for Robert Half, said last week. "And others do well behind closed doors working more autonomously."

Some corporate functions still use offices for privacy: human resources, executive leadership and legal, Naznitsky said. But others are open. She added that it's important for employees to "walk away and have a private experience," such as an area for personal phone calls.

William Belk, an innovation consultant and blogger who conducted an online survey of open floor spaces, said that one moment the spaces feel hip and collaborative and at another moment they seem like the "loudest, most annoying, distracting and unproductive environment one can imagine." He believes they can distract the most highly productive employees.

Buchholz said that the architects and designers have coated surfaces with carpet and other sound-absorbent material to soften the noise and developed many kinds of spaces for employees.

Potential distractions aren't the only issue. Even with its sleek design, clutter constantly threatens Comcast desks and work spaces with set-top boxes in various stages of disassembly, television screens, wires and laptops. Some engineers could be working on multiple set-top boxes at one time, leaving a desk with no room even for a coffee cup.

To avoid the messy desk malaise, Comcast designed custom roll-away bins to store set-top boxes. Some of these bins can be stored under desks. Other larger bins will be more centrally located.

Roberts, Buchholz and other Comcast executives have been developing the new tower for about six years. Early on, Roberts decided he wanted a unique building, not a replica of the Comcast Center. He held a secret competition for the best design – won by Foster – and announced the project in early 2014. Ground was broken later that year.

David L. Cohen, a senior executive vice president at Comcast, captured the contradictions of the new building – the tallest between New York and Chicago – with his observation in a local television interview this year that the new tower "is a building with 1.3 million square foot of office space and no offices."

Liberty Property Trust, the Malvern-based real estate investment firm, is developing the tower and owns 20 percent of it (Comcast owns the remaining 80 percent). LF Driscoll is the general contractor.

Liberty Property – which jointly owned and developed the Comcast Center more than a decade ago – recently warned of $67 million in cost overruns, blaming them on a contract dispute with Driscoll. Liberty has not said what caused the increase. But the building initially had been expected to open in late 2017. Comcast is not responsible for overruns.

Everything about the new tower and its work space is designed to push technology forward, Matt Zelesko, senior vice president of technology and product, said last week. Comcast will do away with the classic desk phone and replace it with the Jabber messaging software – more de-cluttering of the desk space. Jabber connects through employee laptops or other electronic devices, allowing them to talk and listen with a headset.

And there will be large television screens virtually everywhere. The new tower's wireless network will enable those employees to illuminate whatever they want on those screens – doing away with the need for paper printouts, it is hoped.

“Any place we can gather and collaborate,” Zelesko said, “we will have large screens.”