Window Replacement

Hi We have an owner in a small strata of 3 townhouses, (they were also the developers of the complex) who claim that their windows have seized and she wants them replaced. The building is 15 years old, and we are the original owners after we purchased from the developer and in this time I have never seen them open a window. That’s why I think they have seized. We have recently spent $50,000.00 of our own funds(OS funds/ special levies split between ) to conduct urgent maintenance on the building. i.e. replace the balconies.

The replacement of windows is not urgent and the window spindles can be replaced and the windows will be fine. The windows are not rusted or damaged in any way.  We need to have the roof urgently repaired as my townhouse have suffered water damage. What are our rights, because we can’t keep spending on unnecessary items. To replace the building windows the cost is approx. $100K. To replace the window spindles in their townhouse that will cost just over $2K for their townhouse. 

What are our options?