An already tenanted property can guarantee cash flow from the beginning and is easier to find finance.
Be aware of a building being sold where the actual tenant is the seller. This may be a sign of their business not doing well and a need to cash out.
Ensure you get directors guarantees - this allows you to chase the individual persons assets if they do a runner owing money and the business has gone bust.
Check out fully tenants profit and loss statements and their rent paying history. Check also their staffing history - if staff have been cut, then perhaps the business is falling.
If the property is purpose built (ie child care centre) it is harder to obtain finance and usually a larger deposit will be required.
A 3 year period left on a lease as well as an option period is a good place to start.
Government tenancies may offer less returns but are easier to finance as well generally have a longer leasing period.
Tenants should pay for all outgoings including maintenance of airconditioning units, gardens, rubbish removal. There should also be a period whereby the property needs to be painted. Tenant should also have to restore premises back to the state it was in when they first moved in (especially if they have fitted it out for their own purposes but would make it hard for you to re-tenant).
Look into whether you can add additional signage (leased to another company) for additional cash flow as well as phone towers on the roof.
This is just a snapshot of what to look out for. With commercial investing it's a case of learn as you go as leases vary from building to building and business to business.
Good luck and enjoy the ride!
Peter
www.cashflowcalculators.com.au
www.privaterealestate.net.au