Invoice not received via Peppol

As far as I understand, Peppol is only B2B. Your contract for your private residence is B2C, so you can just claim it as before.

I think you can just enter this invoice manually under the correct heading, enter the amount excluding and including VAT as the same amount (because you are not allowed to deduct VAT), and then adjust the percentage to what you want to claim as an expense. At least, that's how I do it ;-)