Thanks to FlightPathOBN for the reference to US and Australian Standards; whilst on the subject, you might wish also to look at the helicopter RNAV procedures contained in ICAO Doc 8168 (PansOps) - to avoid being drawn into specific methods of compliance.
Whilst all of this is good stuff it does not address your issue which is more addressed at heliport design rather than airspace. As you will soon discover from this material, heliport procedures are directly related to aeroplane procedures - starting with the assumption of a runway.
Helicopter profiles are much more flexible than aeroplane's in that the TODRH can be displace in the vertical plane, permitting the origin of the departure/arrival surfaces to be divorced from the surface of the site. This provides a real benefit in two ways: (1) it permits the size of FATOs to be reduced to the absolute minimum - so that they only have to meet the requirement for a reject; and (2) as previously stated, it permits a departure into an obstacle rich environment because the origin of the departure surface can be raised above the surrounding obstacles. This also compensates for the somewhat limited gradients that can be achieved by helicopters following an engine failure. (The real benefit of these vertical profiles is that they permit operations from helipads in congested hostile environments.)
In general terms, the airspace (approach and departure surfaces) have their origin at the end of the Take-Off Distance Available (TODA) and, for that reason, have no knowledge of the type of departure/arrival (the original thinking of the ICAO Heliops Panel was that the TODA would contain both the TODRH of PC1 and the acceleration distance of PC2/3).
From TODRH, complexity diminishes because we depart the world of 'profiles' and enter the world of 'gradients' (gradients because it removes the issues of 'individual' helicopter speeds - i.e. Vtoss and Vy - and concentrates on height gained/lost against distance). This requires some work to stitch together the differing requirements of first and second segment climb performance (although I am reliably informed that the AW139 can reach 1,000ft in the time it takes to exhaust the time limit of the first segment (2 minutes).
My advice would be to leave the issue of IFR (entry/exit to/from PINs procedures) and concentrate on the two issues of visual arrival and departure. Once you have a good handle on these, you can graduate to IFR arrival and departures; however at that stage, you will be subject to the issue of formalised survey - as you will if you are forced to operate to Performance Class 1.
Jim