When using pen and wash both mediums have to be given as much importance as each other.
This is a fantastic building to draw, lots of perspective points, lots of windows and curved structures adorned with an outer coating of foliage.
Use your ruler for measuring purposes and the perspectives of the main roof line. Do not use a ruler to mark in all the windows, bricks, curved lines and marks on the tiled roof. If you use a ruler throughout you will ultimately produce a technical drawing, it is far better to see the character of the artist through their own individual pen strokes.
When your pencil drawing is complete, start using your pens. You will need to use a range of nib sizes, for different widths of line. There are an array of pen strokes you can use in this pen and wash work: some of the ones I used were manic marks (for some of the greenery), broken lines (marks on roof), cross hatch (some of the window panes), curved line (rounded peaked individual roofs), scribble (foliage), stipple (foliage), rectangle shapes – uneven and broken into sections (brickwork), areas of pen – shadow around windows and zig-zag lines for the shadows on the lawn.
When the main body of inking has been completed (you will possibly add some more when the washes have been applied) you can start working on your palette. Colours to consider: a brick red for the roof (I used a burnt sienna mixed with a little burnt umber), a rather neutral colour for the brickwork (I used a yellow mixed with a white gouache and also a flesh tint mixed with a white gouache), a very light blue wash for the sky, some purple for some shadows, a pthalo blue for the windows and then an array of greens for the greenery and lawn (a useful way to create a light, medium and dark green – mix sap green with a yellow, mix sap green with a red, mix sap green with a brown so instantly you have three natural looking green colours).
Wet the sky area. Use a large round headed brush to apply your weak wash of blue, circular brush strokes. Paint the roof, turrets and tower roof next using your brick brown mix. When that is dry, paint in the cast shadows on the main roof, you can darken your brown mix by adding some burnt umber. Use your neutral mix to paint a wash over the brickwork and small chimneys. You do not want this to look too uniform, far better to have some areas that are lighter/darker than others. When dry, glaze over with some of your other flesh tint neutral mix.
Paint the windows with your blue and some of the purple too.
For the greenery:- I would usually recommend under painting with a yellow in a watercolour painting, but for a pen and wash work let some of the colour of your paper suggest light. Use a stipple brush stroke to paint in your light green and whilst that is wet use your medium green over that to suggest darker foliage. Your darkest green should be applied using a stipple brushstroke, again this can be applied to damp paint so it mixes into the medium green to create a further colour on the paper.
Paint the lawn with the light green and represent the shadows with your dark green. When I had got to this stage I then added some stronger pen strokes, the reason being I had used some strong washes, the stronger the washes, the stronger the pen strokes need to be. If you are an artist that works in transparent colours, you may not have to overlay further pen strokes.