Size I am finding is very relative in Z scale. Some buildings seem much too small, while others stem on the fringes of enormity. I like the larger buildings on a layout. The large buildings work if they are to scale. Unfortunately, this kit I would not classify as to scale.
The two stall engine house from Faller is modeled from an engine house that was built around the turn of the century. It is stone construction with large wooden doors. It cries out for the large steam engines to be berthed inside. Large windows with stone fringe showcase the engines nicely. There is a covered area attached to the building covering parts from steam engines and other accessories.
Unfortunately, this kit appears to be a modified N scale structure. The tip-off is the door structure. In the two large doors are inserts where the new doors are placed. The original openings are perfect for N scale, but when modified for Z scale, it does not look quite right. Also, the windows are too large for Z compared to Märklin's engine houses. Once again, N scale comes to mind. The length of the kit is perfect for housing the largest of Z scale steam engines, and catenary is accommodated within the structure. The height is too tall and causes the kit to really stand out on a layout. The attached storage area is much too tall and looks out of place.
As a whole, the kit went together very smoothly. The doors can be a bit complicated to construct as there are springs attached that allow the engines to push the doors open and close. Very liberal amounts of glue is needed around these parts. I found I had to remove flash from around parts 8/2 and 8/12. Be careful not to shave any of the plastic other then the flash off or you might experience some difficulty setting them over the spring and hinge areas. The door hinges are another area where I had to remove flash and sand smooth. This is necessary or the doors will not open smoothly.
When assembling the wall sections, I use rubber bands to hold the walls together while they dry. This will allow for a tight bond.
I elected to leave the windows off until I finished weathering the structure. I use artist pastels and charcoal in the weathering process. Large amounts of charcoal where applied above the doors and around the base of the kit. Light gray chalks where applied on the roof to bring out the details. Streaks of browns and blacks were added to the roof as well.
This was a nice kit overall to build, but unfortunately, I will not be able to use it on my layout as it is. It seems to dwarf even some of my largest buildings. If you are looking for a two stall engine house, I would recommend either kit bashing this structure or combining two of Märklin's single stall engine houses.