Your microgeneration application must be approved and your new house connected to the grid before the microgenerator can be connected in parallel and energised.
Note that you can submit a Microgeneration application form when applying for the house connection. See response to Can I connect my microgenerator to the ESB Network's Low Voltage (LV) system? for details of the connection process and copies of any forms required.
A wiring certificate will be provided to the customer by the Safe Electric Member installing the microgenerator, which the customer should retain for their own use.