A solid concrete pier has been selected, due to its vibration free nature, and cost. A 250mm (10 inch) square pier, 1.5m high will be completely independent of the rest of the observatory structure.
Around the pier a 2.1x2.4m (7x8') ROR observatory is to be built. As we are unlikely to be permanently in this house, it will be constructed in a modular fashion, for ease of disassembly and relocation in the future.