Welded window construction

A low profile window comprising:

• (a) a window frame of a polymeric material including at least two parallel side jambs, a head jamb extending perpendicular to and connecting at welded miter joints the upper ends of the side jambs and a bottom sill extending perpendicular to and connecting at welded miter joints the lower ends of the side jambs;
• said side jambs, said head and said bottom sill are formed of a common master frame and window frame inserts that snap into said common master frame, said master frame in cross-section having a first sidewall and a shorter second sidewall spaced parallel thereto;
• first and second spaced parallel connecting walls transverse to and joining said first sidewall and said second sidewall;
• first, second and third spaced parallel support walls extending perpendicularly from said first connecting wall and parallel to said first and second sidewalls, said first support wall adjacent said second sidewall and projecting from said first connecting wall through said second connecting wall to said second sidewall, said second support wall and said third support wall positioned parallel and adjacent one another and extending from a middle portion of said first connecting wall through said second connecting wall and terminating beyond said second connecting wall and said second support wall terminating short of said third support wall;
• an end section extending between and connecting said terminal ends of said first support wall and said second sidewall to form a shelf therebetween;
• an L-shaped flange protruding from said end section and directed toward said second support wall;
• a crosspiece connecting said third support wall and said second support wall at the terminal end thereof and projecting beyond sides of said second and third support walls;
• a traingular shaped extension extending from a point of intersection of said second connecting wall and said first sidewall, said triangular extension having a protruding channel sidewall connected thereto and parallel to said first sidewall and terminating at a distance approximately equivalent to the projection of said first sidewall;
• said first and second connecting walls, said first and second sidewalls and said first, second and third support walls, end section, crosspiece and triangular shaped extension cooperatively forming said master frame cross section;
• and
• (b) at least one sash of a polymeric material and including a glazing having outer peripheral edges, at least two parallel side stiles, a top rail extending perpendicular to and connecting at welded miter joints the upper ends of the side stiles and a bottom rail extending perpendicular to and connecting at welding miter joints the lower ends of the side stiles to completely enclose the outer peripheral edges of said glazing, said top rail, said side stiles and said bottom rail constructed from a common master sash and at least one sash insert, said common master sash generally having a double wall h-shape cross-section and a plurality of sash crosspieces extending between said double walls of said master sash to reinforce said master sash such that said at least one sash insert in cooperation with said master sash surrounds the outer peripheral edges of said glazing to form said sash, said sash confined within said window frame to produce said low profile window.