3D-printing scaled building massings for site models is common practice. It’s really important that your files are prepared properly, otherwise these projects can use a massive amount of material and machine time. Rather than submitting print jobs with monolithic building volumes – the best method is to create thickened shell with an open face, then printing it with the open-face facing up. This method avoids the need to fill the entire volume with infill which minimizes unnecessary material waste and often reduces print times.

process

Begin with closed polysurface scaled massing models.
Create a thickened shell of the massing so the majority of the interior is hollow. This can be easily done by using the SHELL command in Rhino. The ideal thickened wall is 3-6mm [roughly 1/8 – 1/4″].
FLIP the massing so they can print without infill or support material. This will significantly reduce the print-time and material used.
massings printed with infill	massings printed as shells

TIPS:

infill

you can turn the infill of your print down to 10%. Do not go lower than 10% as the chance of failure is significantly higher.

bed adhesion

a brim can be beneficial to minimize warping of the print. Rafts and skirts are not recommended. 

overcrowding

Only cover a maximum of 60% of the print bed. Going over this is the cause of a high percentage of print failures.

support material

always orient your part in a way that minimizes the amount of support material required. this maximizes your chances of a successful print.