There are three different construction processes possible for building Tibetan stupas:
The Dharma Sanctuary has experience with one type of construction, a stupa made of stone. This is a method of using a crane to stack eight pre-carved marble blocks, and inserting the ninth and final gawo block in the keyhole of the bumpa. The stupa is hollow, and the traditional process of adding zung is followed. The size of a stupa is limited by the ability to ship and truck the stone to the site. A 20 ft shipping container can hold all the parts for a 15 ft stupa with a 7 ft x 7 ft base. There is no need for a plaster skin or paint. There is almost no maintenance with stone. Longevity is great, and the clarity of a living crystalline stone is breathtaking. Erecting a marble stupa is quick and relatively easy, needing no engineering skills.
The second construction method, which is most common in the West, is the pouring of concrete into complicated wooden forms. Very large stupas can be built this way. A synthetic plaster skin is usually applied to the exterior and then painted. There is ongoing, sometimes expensive maintenance to keep this exterior looking presentable. Longevity is good, but not as great as stone. This type of construction needs many skilled and knowledgeable workers, and takes time.
The third method commonly used in Asia, is building with brick or concrete block. A plaster skin is added and then painted. Maintenance is needed to keep the exterior skin intact so that the block underneath will not erode. This method has the least longevity and is dependent on upkeep. Construction workers must be skilled and knowledgeable, but need not be at the level required for building with concrete forms.
Stupas can be built in any size. If they are big enough, they can have an inside space for people to sit or walk around. Some of the larger ones have a second and third story.
As this web site is developed, we will point you to others who have experience in various construction methods. The Dharma Sanctuary can help you with marble stupas, if you choose this method.