There is no general answer. The larger items may be:
– a managing agent’s fee. You could ask several agents to provide a quote.
-a grounds maintenance contractor and/or cleaner. Again, you could check if their fee seems reasonable on an hourly basis for what they do.
-other routine maintenance. What did it actually cost for the last few years to do routine things like replace light globes or get gutters cleared. Do you usually need to get an electrician or plumber out a couple of times a year? If so, factor that in.
-building insurance. My observation is that this goes up gradually every year then every 5 years or so one of the strata insurers decides to substantially undercut the others and we get a windfall from changing insurer. Get quotes.
-sinking fund plan (or whatever other states call it). This is the long-term planning for things such as remaking sections of damaged path, resurfacing asphalt, having a contingency provision for a burst water main, infrequent scheduled maintenance of machinery such as lifts or fans or whatever, repainting, replacing carpet when it gets worn. Start with a list of everything you have on the common property. You might find it is relatively simple and you can make some sensible estimates of the cost and frequency of repairs and replacements and a generous contingency margin. You might find it is complex or some major items are difficult to estimate with confidence. Then get advice. However you work out a schedule of costs over 10 or more years, then work out how much needs to go into an interest bearing account each year to cover it.
-utility bills. What have they been for the last year or two?
-other minor bits and pieces. Do you print a newsletter?
-Are there improvements that a general meeting might consider and approve? These could be a park bench for under a tree in the grounds through BBQ facilities to solar electric equipment to offset the OC’s electricity costs.
Anyway, just work out the various parts and the sum of those plus a bit of contingency is what your levies should be.