Rinpoche said these are things that need doing before building starts:

• The Diamond Cutter Sutra needs to be recited three times.
• Padmasambhava incense offering (Nolsang Incense Ritual: The Divine Blue Water Clearing Away Contamination). This needs to be done five times on the land, at the site of the future nunnery.
• Protector prayers and tea offering, to be done in the gompa once each day for several days. Of course, if you do this regularly/daily, there’s not more to do.