All properties with architectural or heritage merit - including 38, Oxley Road - should be subject to due process, said Minister for National Development Lawrence Wong.

This means a "rigorous assessment process" for all such properties before deciding whether to conserve or preserve them, he told Parliament. He said various agencies had been working on the issue, even before the formation of a ministerial committee last year. The National Heritage Board (NHB) had been documenting the historical significance of the house, while the Urban Redevelopment Authority (URA) looked at planning and zoning implications under various scenarios.

Explaining how the Government decides whether a property should be gazetted as a national monument or conserved, Mr Wong said the NHB would review a site's role in Singapore's history, while the URA would study architecturally significant aspects of a property.

Agencies would then look into the planning considerations for the property and its surroundings, and review allowable uses of the site.

For example, the URA may look at whether a conserved residential building can be adapted for commercial or community use. These are subject to technical and infrastructural constraints, like whether the surroundings can support higher traffic volume.

Agencies then need to consider whether the Government should acquire the property - which includes weighing up whether it is "best served by having the Government owning the site, as opposed to leaving it under private ownership".

They will seek stakeholders' views, and should the Government decide to pursue conservation or preservation, the property owner will have a chance to respond.