Method for connecting plastic hollow-chamber profiles (1, 7) in the corner region, in which at least two hollow-chamber profiles (1, 7) of different cross-sectional contours are welded to one another in the corner region, wherein - at least one first hollow-chamber profile has an overlap chamber which slopes down obliquely in the outward direction at a first angle α in relation to the outer visible surface, and - at least one second hollow-chamber profile has an overlap chamber which - runs perpendicularly to the outer visible surface or - slopes down obliquely in the outward direction at a second angle β in relation to the outer visible surface, said second angle differing from the first angle α, characterized by the following method steps: a) to form a mitre region, the first hollow-chamber profile is trimmed or milled using a saw cut or a corresponding milling cut which runs perpendicularly to the outer visible surface and at 45° in relation to the longitudinal extent, and extends up to a distance "A" from the outer visible surface over a large part of the depth of the first hollow-chamber profile, and to form a lap joint of thickness "A" a second saw cut or using a corresponding milling cut is performed which cut runs parallel to, and approximately at a distance "A" from, the outer visible surface; b) to form a mitre region, the second hollow-chamber profile is cut or milled perpendicularly to the outer visible surface and at 45° in relation to the longitudinal extent and up to a line "B", said line "B" running at an angle δ in relation to, and at a distance from, the visible surface of the overlap chamber, c) the outer side of the second hollow-chamber profile is removed by sawing or milling to form an overlap-joint recess with an edge up to approximately the distance "A" from the outer visible surface, said edge running perpendicularly to the longitudinal extent; d) the second hollow-chamber profile is recessed in the region of the overlap chamber by a saw cut or by a corresponding milling cut which runs at an angle α in relation to the outer visible surface up to the line "B", wherein the method steps a) to d) can also be carried out in a different sequence; e) the first hollow-chamber profile is welded to the second hollow-chamber profile in the mitre region (5, 11), wherein the lap joint of the first hollow-chamber profile covers over the overlap-joint recess of the second hollow-chamber profile. - at least one first hollow-chamber profile has an overlap chamber which slopes down obliquely in the outward direction at a first angle α in relation to the outer visible surface, and - at least one second hollow-chamber profile has an overlap chamber which - runs perpendicularly to the outer visible surface or - slopes down obliquely in the outward direction at a second angle β in relation to the outer visible surface, said second angle differing from the first angle α, - runs perpendicularly to the outer visible surface or - slopes down obliquely in the outward direction at a second angle β in relation to the outer visible surface, said second angle differing from the first angle α, a) to form a mitre region, the first hollow-chamber profile is trimmed or milled using a saw cut or a corresponding milling cut which runs perpendicularly to the outer visible surface and at 45° in relation to the longitudinal extent, and extends up to a distance "A" from the outer visible surface over a large part of the depth of the first hollow-chamber profile, and to form a lap joint of thickness "A" a second saw cut or using a corresponding milling cut is performed which cut runs parallel to, and approximately at a distance "A" from, the outer visible surface; b) to form a mitre region, the second hollow-chamber profile is cut or milled perpendicularly to the outer visible surface and at 45° in relation to the longitudinal extent and up to a line "B", said line "B" running at an angle δ in relation to, and at a distance from, the visible surface of the overlap chamber, c) the outer side of the second hollow-chamber profile is removed by sawing or milling to form an overlap-joint recess with an edge up to approximately the distance "A" from the outer visible surface, said edge running perpendicularly to the longitudinal extent; d) the second hollow-chamber profile is recessed in the region of the overlap chamber by a saw cut or by a corresponding milling cut which runs at an angle α in relation to the outer visible surface up to the line "B", wherein the method steps a) to d) can also be carried out in a different sequence; e) the first hollow-chamber profile is welded to the second hollow-chamber profile in the mitre region (5, 11), wherein the lap joint of the first hollow-chamber profile covers over the overlap-joint recess of the second hollow-chamber profile.