[17] Frustrated by legacy designs and typically unsuited cockpits, Stucki had observed that the light single-engine helicopter market had not seen any all-new designs in decades, and he conducted market research that indicated a viable demand for a new rotorcraft in the 2.5-tonne class.

Its airframe is entirely composed of carbon composite materials; it employs a shrouded fenestron tail rotor and a high-visibility cockpit.

According to Mathias Senes, Marenco's chief commercial officer: "There’s no other material today that brings the benefits of rigidity, strength, and light weight".

[17] Stucki approached his design from a pilot's perspective, attempting to improve ergonomics, comfort, and operator requirements.

It possesses excellent hot and high performance, lengthy flight endurance, a low noise signature, and has relatively smooth handling.

[17] A small number of staff worked on the project, initially being a team of nine; an emphasis was made on recruiting very high quality engineers, including from other rotorcraft manufacturers such as Airbus Helicopters; the company had over 100 employees in 2016.

P2 and P3 are the main vehicles for airworthiness certification testing; they are more representative of production aircraft, their design incorporating several refinements.

[33] In May 2016, it was reported that Marenco were increasing the pace of the flight test program, that P3 was to be completed within that year, and that type certification should occur during 2017.

[43] During the 2018 Heli-Expo, Kopter announced 23 firm orders and 11 options worth $119 million from Norwegian Helitrans (12+6), Elling Halvorson for Rainier Heli Lift, Hawaiian Paradise Helicopters and South African Safomar Aviation.

[17] The monocoque fuselage is made from composite materials and is equipped with sliding side doors on either side along with a rear clamshell door; it incorporates a series of floor-mounted windows between the pilots' seats for additional vertical visibility.

[10] It has been stated that the firm has sought to introduce the cabin volume of medium-sized twin-engine helicopters to the single-engine market.

The use of Kevlar-threaded crashworthy fuel tanks, which are built into the wall and floor of the cargo hold, freed up space to allow for fully adjustable passenger seats in the cabin.

[17] The rear clamshell door and high-mounted tail boom were designed for air ambulance applications.

[17] A Sagem-built ICDS-8A glass cockpit suite is an integrated part of the SH09's standard avionics and instrumentation package.

[48][10] The rotorcraft has been designed with a condition-based maintenance policy, specifying that there should be no time between overhaul (TBO) limits on its various components and systems, including the engine; instead, maintenance is performed based upon condition, which is continuously monitored at all times by an onboard health and usage monitoring system (HUMS).

[17] In January 2023 Leonardo announced that the helicopter would be powered by the Safran Arriel 2K engine in place of the originally planned Honeywell powerplant.