Here is what Lama Yeshe says about the Benefits of Building a Dharma Center...(this was his advice for FPMT at that time)
I've extracted the parts which I thought was good summary. Definitely if we get an opportunity to build any holy space i.e. a Dharma center, we should grab it!
The Function of a Dharma Center [posted July 2009]
Rinpoche made the following comments on the function of a Dharma center.
The benefit of the center is to learn Dharma practice, which means purifying defilements and collecting merits/good luck/ good karma, attaining the path to liberation and full enlightenment, and liberating numberless sentient beings from the oceans of samsaric sufferings and bringing them to full enlightenment. That means, along the way, bringing peace to the world, because the essence of Buddhadharma is compassion.
When you practice Dharma the essence is compassion for all sentient beings. Besides that, there is service to others, service to people, service to animals, praying and doing pujas for the sick, dying, and the deceased. It is very important to help the families of the center members, to help them pray.
Building holy objects and circumambulating them, making offerings, etc, creates merit. This merit comes from virtue/good karma. This is all due to the power of the holy object. Even if one doesn’t have a virtuous mind, due to the power of the holy object, one creates merit.What you are doing is helping us accomplish limitless skies of benefit for sentient beings and the teachings of Buddha, benefiting sentient beings not just by giving shelter, food, and medicine, etc. Of course, those things are very good, but they are not enough because they don’t purify the past negative karma of this life, nor all past lives’ negative karmas, which have not been purified, and the results of which are still to come, as well as negative karma from numberless past lifetimes from beginningless time, which brings all difficulties, unbelievable sufferings, physical sufferings, and mental sufferings, as well as war, famine, disease, torture, poverty, everything. If one doesn’t purify these things, and one doesn’t purify the mind, then material things alone won’t help, because they don’t transform the mind from anger into loving kindness and compassion, from desire into renunciation, the satisfied, content, free mind, seeking the happiness of future lives, or, more pure than that, seeking liberation from samsara, detachment from samsaric pleasures, and from the self-cherishing thought. It is from this that all obstacles, undesirable things, and sufferings come. It must be transformed into bodhicitta and cherishing others, which is where all happiness comes from, temporal and ultimate happiness, up to enlightenment.
Due to this project, many thousands of poor people in India will get jobs so they can get food for their families and put their children through school. Also, it is a different type of work to building a factory or a building that is used for business offices. This project is so different because of the power of the holy object. Even if the people working on it do not practice Dharma, because of the power of the holy object, then
all this work becomes Dharma and virtue, which is the cause of happiness. The Dharma center is an emergency rescue operation, like when police go in with sirens blaring, red and blue lights flashing, helicopters whirling, to rescue people in distress. Like that, the meditation center plays a very important role in the emergency rescue of human beings, using the seat belt and life jacket of the lam-rim. Meditation on refuge and karma immediately saves you from falling into the lower realms again. Why is there a need for a larger place to listen, reflect, and do meditation practice on the kind, compassionate Buddha's path? One can understand by analyzing how the need for Buddha Dharma is much more important, many billions of times more crucial, than going to the emergency room in the hospital when the heart stops. Why? Because suffering and happiness do not come from outside. They come from the mind.
Compassion never allows harm to be given to others, and besides that is only to benefit others. A Dharma center such as this becomes a very important tool to bring peace in the world, and peace in numberless sentient beings’ minds. So, whatever you are able to contribute benefits not only peace in this world but for all sentient beings. You can see how the Dharma center, which offers these practices and education, is an extremely important need. Therefore, I would say it would be an extremely practical thing to help this Dharma center so all these facilities exist and flourish.
http://www.lamayeshe.com/index.php?sect=article&id=257&chid=1225