Method for installing a sunshade in the light opening of a building element and a building element

A building element comprising a light opening, which building element is a window element or a glazing unit for a patio or a balcony, having a first edge surface, a second edge surface, and a glazing unit extending from the first edge surface to the second edge surface;

• wherein at least one of the first and the second edge surface comprises at least two fastening holes each having a first end, which open to the first or to the second edge surface, respectively, and
• each fastening hole contains a respective plug comprising a stem having a cavity opening to the respective first end of the fastening hole, wherein an outer surface of the stem of said plug comprises flexible gripping tabs and said cavity has a cylindrical shape, and a wall of the cavity has an internal thread, and the plug further having a removable or penetrable lid configured to close the first end opening of the respective fastening hole;
• and wherein each plug is configured to receive and fix a respective fastener for an installation rail for a sunshade, wherein
• each fastener comprises a tip part and a head part, and each cavity of each respective plug is configured to receive the tip part of a respective fastener through the first end of the fastening hole upon removal or penetration of the removable or penetrable lid while the head part of each respective fastener remains outside the respective fastening hole, and
• wherein said tip part of the fastener has an elongated shape, a free end and a slot extending from the free end towards the head part and cutting through the tip part,
• a surface of the tip part of the fastener is provided with an external thread, the external thread being compatible with the internal thread on the wall of said cavity, and
• said external thread comprises an upper threaded surface that is closer to the head part of the fastener, wherein the upper threaded surface is substantially perpendicular to a longitudinal axis of the tip part, and a lower threaded surface that is closer to the free end of the tip part, wherein the lower threaded surface is arranged at an obtuse angle to the longitudinal axis of the tip part.