Cutting out the template

Make a clay slab using white clay 100 cm x 50cm and 10mm thick. Cover the slab in cling film and lay out your template pieces, use tape to keep them in place. Roll the pieces firmly into the slab (I roll them through my slab roller).

Cut out your pieces and score all joint edges around the base. Mitre the corner edges and the edge where the three rooftop pieces join to each other. Mitre the front and back top wall where the roof will rest. Mitre them all at 45° with the long edge towards the outside, so template face down.

Let them dry to leather hard on concrete Hardibacker board or a plaster bat with another board on top to prevent warping.

Assembling the walls

Wait till the pieces are the firm side of leather hard. Assemble the left hand end wall, then the back wall, the right hand wall and the front in one session to allow for adjustments. Add coils to all the inside seams to reinforce, and blend them in.

Assemble the porch roof first, then the main roof back and front, then the dormer. Score and slip all the parts where pieces join. Finally turn the piece around to check for a smooth, blended finish on all seams, using soft clay coils to fill and reinforce any gaps.