We are pursuing LEED V4 NC Certification for a building that is part of a University Campus.

The project is located in Lima, Peru, where the climate is ideal for natural ventilation and often not even cooling, and especially no heating is needed, which is our case. So we have a project which is only naturally ventilated, without heating/cooling.

To comply with the option of whole building simulation to obtain the credit we are encountering some problems..

1.) On the one hand, we are not entirely sure how to model the HVAC system, for the energy consumption comparison:

a.) Is it ok, to simply not model any HVAC system, neither in the Proposed building nor the Baseline building?
b.) Do both buildings have to be modeled with X-Hvac system, which, due to either high temperature setpoint or schedule configuration, never turns on and therefore does not register any consumption?
> ideally both options have the same result = zero registered energy consumption, it's mostly a question of procedure--

2.) On the other hand, if there are no energy consumptions and consequently no energy saving when not using any HVAC system, savings can only be achieved through components such as lighting.. Is it possible to claim savings that are only due to lighting? or are there any other conditions required to fulfil?
Further, how could  the savings for natural ventilation be claimed?What are the conditions to be able to claim them and in what range do the unmet hours of comfort have to be?