Mechanical Penthouse Design Maximizes Space and Efficiency

A mechanical penthouse is a compact, elevated space that houses mechanical equipment, such as air conditioning units, fans, and pumps, to serve a building.

This design maximizes space and efficiency by locating the mechanical equipment in a single, easily accessible area.

The mechanical penthouse is typically located on the roof of a building, allowing for easy maintenance and replacement of equipment.

In some cases, the mechanical penthouse can be designed to be a multi-story structure, with equipment located on multiple levels to optimize space usage.

A mechanical penthouse is a rooftop enclosure that houses mechanical, electrical, and plumbing (MEP) equipment. It's a popular alternative to locating this equipment in the interior of a building, where valuable space is often hard to come by.

To be classified as a mechanical penthouse, there are specific height and area limitations. Unless the building is of Type I construction, the penthouse is limited to a maximum height of 18 feet above the roof deck, with some exceptions.

The area of the penthouse is also limited to 1/3 the area of the supporting roof deck. This helps maintain a balance between the need for equipment space and the potential impact on the building's overall size.

Penthouses are limited to mechanical or electrical equipment only, and cannot be used for storage or small offices. They must also be constructed of materials consistent with the building's construction type.

In some cases, a mechanical penthouse may be required to have two means of egress, depending on its size and location. This is an important safety consideration that must be taken into account during the design and construction process.

Here are the key requirements for a mechanical penthouse:

The design of the Novant Health Ballantyne's mechanical penthouse was a game-changer for patient care space.

The hospital's mechanical penthouse was located on the roof, which allowed for a more compact footprint and freed up space for patient care.

This compact design enabled the hospital to maximize its patient care space, with a total of 170 beds spread across the facility.

The hospital's designers made the most of this space, incorporating a variety of patient rooms, including private rooms and semi-private rooms.

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Some of the world's tallest buildings have mechanical penthouses that are counted as floors, leading to higher total floor counts than usual. This is the case with the Taipei 101, where floors 92-100 contain communications equipment and are not typically counted as mechanical.

In Taipei 101, the official count of 11 corresponds to the number of groups in the office section. In contrast, the official count of floors in the One World Trade Center is 104, but it actually has 28 mechanical floors.

Here's a comparison of some of the buildings mentioned in the article:

The mechanical penthouse in the Taipei 101 contains communications equipment, but in the One World Trade Center, floors 92-99 and 103-104 are mechanical floors.

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In some of the world's tallest buildings, you'll find mechanical floors and penthouses that are counted as floors, but aren't always used as such. For example, Taipei 101 has 17 penthouse floors that contain communications equipment, but aren't typically considered mechanical floors.

Penthouses offer several benefits, including being exempt from height and area evaluations, as well as means of egress requirements. This is because they're considered normally unoccupied spaces. Taipei 101's penthouse floors are a great example of this, as they're used for communications equipment and aren't subject to the same requirements as occupied floors.

The main difference between a penthouse and a mechanical floor is the way they're classified in the building code. Penthouses are considered part of the story below, which means they're not included in the building's height or area evaluation. This can be a significant advantage, especially for tall buildings like the Petronas Towers, which has a penthouse that's part of the 43rd floor.

To be classified as a penthouse, a rooftop structure must meet certain requirements, including a maximum height of 18 feet above the roof deck, unless the building is of Type I construction. The area of the penthouse must also be limited to 1/3 the area of the supporting roof deck. For example, the Jin Mao Building's penthouse has an area of 7/93, which is well within the allowed limit.

Here's a comparison of the penthouses in some of the world's tallest buildings:

Note that the number of penthouse floors can vary significantly between buildings, and not all buildings have penthouses. However, for those that do, the benefits can be significant.

For another approach, see: Gambrel Roof Steel Buildings

145 Broadway is a great example of how prefabricated mechanical penthouse skids can speed up construction timelines. This 570,000 SF mixed-use building was completed in 2019 and utilized prefabricated mechanical penthouse skids.

The prefabricated skids allowed the construction period to be shortened from 5-6 months to just 6-8 weeks. This extra time saved allowed the interior fit-out process to start earlier.

A typical mechanical penthouse construction period would take around 5-6 months, but 145 Broadway's period was shortened by 10 weeks. This significant reduction in construction time provided cost savings and allowed the tenant to move into their new home ahead of schedule.

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