The Buddha taught that the supreme means of accumulating merit and wisdom through our body, speech, and mind is through building monasteries and teaching centers, especially where there have been none before. Of the three types of generosity—material generosity, generosity of giving protection, and generosity of giving the Dharma—the highest is Dharma generosity.
But just wishing to provide the Dharma is not enough—there must be a place for people who need the Dharma to meet. Once the monastery is completed, it will not be a place where only one person comes; it will be a place where thousands of people come. And it will not be a place where only one person teaches, as there will be many different teachers. And with many teachers and limitless students meeting in a place where there was no monastery ever before, there is a tremendous benefit. The peerless benefit of making the teachers and the Dharma available continues not for one day or a year, but for generations. And within those generations, the benefit that comes from this project will be limitless.
There is a reason why the Buddha said that building teaching centers and monasteries where none existed before is a supreme means of accumulating merit. When you truly help one individual through material generosity, or protection, or by giving the Dharma, there is a great benefit indeed. But the help that you are providing is to only one person. When you build a monastery, you benefit countless beings, and the merit that you accumulate is supreme.
Even when there is no teaching going on within the monastery, by simply being there it inspires the mind and develops the devotion of people who visit. Through such inspiration, people come to follow the path and are led to its fruition; this could be the result of their initial contact with the monastery and the Dharma. The merit in this is beyond any conception.