When creating the iron bars, we can use the same technique which we used while creating the bars for the windows.
Let us first draw the door design when creating the door. Let us draw a box the size of the door and let us convert it to 'editable poly' mode. Then let us select the edges on all four sides and use 'connect'.
With the diamond shape that has now appeared, let us choose two sides of the diamond and let us also choose the parallel edges and use 'connect' again. (I used connect = 4. You can change it according to the size of the diamond shape you desire by increasing or decreasing).
Later let us choose all the remaining sides and 'connect' them.
As in the picture, let us choose the first diamond shape that appeared at the beginning and all the edges inside it. Let us then apply 'chamfer' on them.
Then let us choose the polygons between the edges that we applied 'chamfer' on and let us extrude them.
After having applied 'extrude', let us click 'grow' and then choose the sides of the polygons that we had 'extruded'. Let us then choose 'detach'.
We have completed the ornament for our door. Now let us create the door itself and attach the ornament on it.
To create the lamps, let us draw a hexagon and then by using 'scale' let us make the bottom part smaller.
Let us select the side surfaces and apply 'inset'. While doing this, let us not forget to select the 'by polygon' option.
For the surfaces that we used 'inset', let us 'extrude' them inwards.
Let us shape the top and bottom parts by using 'extrude' and 'inset'.
To add details to the lamp, let us attach the pieces we have drawn with 'line'.