This is interesting. In line with the scarce of land in Singapore government has amended the rule for underground space.
As reported in Property Guru, 13 February 2015
The government plans to revise the State Lands Act and the Land Acquisition Act in order to facilitate its long-term plans for the usage and development subterranean space in Singapore, where land is scarce.
In particular, it wants to amend the State Lands Act so that land owners of commercial and residential properties would only be allowed to develop their underground space up to a depth of 30 metres under the Singapore Height Datum.
The Height Datum is a fixed level from which height measurements are based in the city-state.
At present, the law does not specifically set a boundary for subterranean ownership. It only says that land owners own the underground space, to a depth reasonably necessary for the use and enjoyment of the property.
The proposed changes seeks to address this ambiguity, but the Ministry of Law clarified it will not impact how land owners make use of their underground space. For instance, the drilling for foundation works will still be permitted to the required depth.
In general, subterranean construction works can be extended to a depth of about 15 metres. For example, ION Orchard’s underground basement has depth of 10 metres, while the development beneath Fusionopolis is 15 metres deep so that the One-North MRT line can be built.
Additionally, the government plans to revise the Land Acquisition Act so the government can purchase a specific portion of underground space or airspace should it be necessary for the construction of a public project. This will also lessen inconveniences, especially for landed property owners.