To mark the Istana's 150th anniversary, President Halimah Yacob will launch a model of the presidential residence on Labour Day next week.
The Istana grounds will be open to the public between 8.30am and 6pm next Wednesday.
The model of the Istana building was specially commissioned by the President's Office for the occasion, and showcases the Istana's neo-Palladian architecture with its surrounding verandas and grounds.
Visitors who make a minimum donation of $70 to the President's Challenge will receive a model of the Istana, the President's Office said in a statement yesterday.
The model, made with Lego bricks, was created by a certified professional from Lego.
Visitors to the Istana open house on Labour Day can also look forward to a space-themed exhibition and a variety of performances, including acts by special needs groups from Delta Senior School and Rainbow Centre.
There will also be performances by Alexandra Primary School, Yishun Primary School, Nanyang Polytechnic and Temasek Junior College.
At the Journey to Space exhibition, visitors will be able to control models of a Mars Rover and an artificial intelligence car. They can also take a closer look at the sun using a special solar telescope, and launch water or dry rockets on the Istana lawn.
The exhibition is organised by the Singapore Science Centre with the support of the Lifelong Learning Council and SkillsFuture Singapore.
There will also be booths for henna painting, balloon sculpting and ice cream.
Those interested in the Istana's flora, fauna and biodiversity can sign up for a guided nature walk.
There will also be a guided tour of the Istana main building, where visitors can view selected function rooms and collections of state gifts presented to the president and prime minister.
Visitors can also learn more about Singapore's history and heritage at the Istana Heritage Gallery, which is located at Istana Park, opposite the Istana's main gate in Orchard Road. The Istana Heritage Gallery will be open from 10am to 6pm.
Entry to the Istana grounds is free for Singaporeans and permanent residents. All other visitors are required to pay a $2 entrance fee.
Correction note: This article has been edited for clarity.