My mum just bought a old HDB flat and is currently doing renovation. As you can see in the picture, the old aircon in the master bedroom has been removed and we are left with a hole. The ID said he will just cover up with wooden plank. But we are concerned that this is not a long term solution as rain water will seep through. Anyone know if HDB allows us to use bricks to cover up this hole ? Any inputs or suggestions greatly appreciated.

I faced the similar problem as you too, but my old aircon casement window was in sealed condition, unlike urs.

One of the contractors we talked to, suggested us to do a window at that hole. He quoted us $150-200.

In the end, we decided to do a plasterboard to cover the whole wall. However I'm not sure tat will keep out water for ur case...

HDB website has a detailed list on items of reno that are not allowed.

My mom' house was also patched up with a piece of plank so far no problem after more than 10 years. I believe your id/contractor would use silicone on the edges to prevent water from seeping in. If you're worried about the plank rotting etc, ask him to use waterproof plasterboard

Thank you for all the replies. Our ID said he will check with HDB next week.

Let's us know ur final decision, k?

My mum just bought a old HDB flat and is currently doing renovation. As you can see in the picture, the old aircon in the master bedroom has been removed and we are left with a hole. The ID said he will just cover up with wooden plank. But we are concerned that this is not a long term solution as rain water will seep through. Anyone know if HDB allows us to use bricks to cover up this hole ? Any inputs or suggestions greatly appreciated.

U can use alum. sheet to seal the exterior just like the old unit installed the air con. As for interior u can use water resistance plasterboard to seal it.

better use hollow block seal up if u dont ever intend to use casement aircon there

Safety issues, don't think hollow block is allow. And how to plaster the exterior part? Don't think any tiler will risk their life to do that.

My ID said he checked with HDB and it is not allowed to use bricks to cover up the aircon hole. He is getting his contractor to assess and quote based on the various suggestions in this thread. This will be additional cost liao

This might help?

bro, no need to wait for hdb...

Just ask your contractor to clean up and repaint the existing wooden frame so it will not rot then cover with marineply...

very easy to diy also.... after make sure to silicon the sides....

Sorry to bump up this old thread but I'm currently facing this situation after removing a window aircon after upgraded to a split system.

I'm thinking a simple fix is to get a piece of white acrylic and mount over the wooden corner on the aircon hole. This way, I can also allow sunlight to come into the room.

Any comments if I do this?