h = 0.5;

y = 2;
x = 1;

Point(1) = { x/2., y/2, 0, h};
Point(2) = {-x/2., y/2, 0, h};
Point(3) = {-x/2.,-y/2, 0, h};
Point(4) = { x/2.,-y/2, 0, h};
Point(5) = {-x/2.,   0, 0, h};
Point(6) = { x/2.,   0, 0, h};

Line(1) = {1, 2};
Line(2) = {2, 5};
Line(3) = {5, 6};
Line(4) = {6, 1};

Line(5) = {5, 3};
Line(6) = {3, 4};
Line(7) = {4, 6};

Line Loop(1) = {1, 2, 3, 4};
Line Loop(2) = {-3, 5, 6, 7};
Plane Surface(1) = {1};
Plane Surface(2) = {2};

Physical Line("fixed") = {6};
Physical Line("loading") = {1};
Physical Line("interface") = {3};
Physical Line("sides") = {2, 5, 7, 4};

Physical Surface("body") = {1, 2};

Recombine Surface "*";
Transfinite Surface "*";
Mesh.SecondOrderIncomplete = 1;