There is a musollah available for muslimah and muslimin at level 3.
1. Take the escalator up to level 3. 
2. Walk towards the direction of the toilets. 
3. When you reach the toilets, between the female and male toilet, you will see the musollah. 
Prayer mats, telekung are provided (some donated by Sister Haney). Slippers are provided as well.
Ablution can be done at the toilets beside the musollah.

Credits to MeokjaSG

(UPDATE 18/11/2022: We have been informed that this unofficial prayer area has been removed)

There is a shared unofficial prayer area in Junction 8. 

From Bishan MRT (NS17/CC15), Exit A.
1. This would lead you to the main entrance of Junction 8. Turn right and walk towards the Junction 8 Linkway entrance. 
2. Walk towards the escalator leading to level 2. Then walk towards the main building of the Junction 8. You will pass by a Prism+ store and the escalator. 
3. When you see the Prism+ store (#02-24/25), turn right, and walk towards the toilets. You may perform your ablution in the toilets here. 
4. Once you've performed your ablution. previously on the right of the toilets is a door leading to the staircase. Walk towards that staircase. Please note that the door only opens one-way and there should be a stopper to keep the door open which the cleaner has placed. Please leave this stopper there so that you do not get trapped in the staircase.
5. Once at the staircase, go down one flight of stairs and you will be at the shared unofficial prayer area for muslimah and muslimin. There is a prayer mat and a set of telekung (donated by Sister Azna) hung on the railing. After performing your prayers, please be sure to hang this back on the railing to prevent any obstruction to the cleaner aunty/uncle. 
If the event you do get stuck in the staircase, you can either check if the door to the floor upstairs is open, or alternatively walk down to level 1 and exit from there. 

​Alternatively, you can go to the nearest mosque is Masjid An-Nahdhah (Bishan Street 14, S579786), about 6 minutes walk.