For the first time on an Airbus aircraft the A350 XWB nose section's outer shape incorporates a flightcrew escape hatch, as the side windows are fixed and not openable.
When Airbus reconfigured the A350 in 2008 re-naming the aircraft as XWB Xtra Wide Body, they changed the shape of the upper radius and upper shell of the fuselage for aerodynamic reasons. And they refined the a six-windscreen layout and worked to minimize the centre post to improve the pilots' visibility.
Additionally, removing the opening direct vision cockpit windows for flightcrew emergency evacuation and including an escape hatch in the flightdeck roof instead, there is a weight reduction.
This was the result of a trade off after benchmarking the configuration Boeing was using in the 787.
787 (in the left) and A350 XWB (in the right) includes the escape hatch in the roof
The whole cockpit canopy section has aluminium alloy skin panels (in green primer in the photos), which offers "the best solution in terms of the overall balance between weight/cost/manufacturing process/bird impact test" as per Airbus.