I think you may have misread my post - I tried to make it clear that you don't deduct financing costs or income tax in calculating the net yield on a rental property.
The gross yield on a rental property generally refers to the realistically achievable annual rent expressed as a percentage of the acquisition cost of the property, assuming no voids or defaults on the part of the tenant. Bear in mind that the acquisition costs includes stamp duty, land registry fees, legal fees (plus VAT), in addition to the purchase price itself.
To arrive at the net yield figure you deduct a percentage amount to provide for all void periods as well as all costs and expenses, actual and imputed. Costs would include letting and management agent commissions, annual OMC charge and levies, LPT, PRTB registration fees, maintenance and repairs, advertising, insurance, legal and accountancy costs. Even if you self-manage a property, you should still account for your time in this calculation in order to arrive at a useful figure to compare with the yield on purely passive investments such as deposits and equities.
Having reviewed rental accounts over a prolonged period of time, I would suggest that a gross yield figure should be reduced by 30% to arrive at a useful net figure. Some years expenses will be well below this amount but, as anybody who has ever had to evict a defaulting tenant will tell you, some years they can be well above this amount. In my experience, 30% represents the average amount of expenses, actual and imputed, that a residential rental property will consume from the (anticipated) gross yield over a long-term holding period.
On this basis, a net yield of 7% actually implies a gross yield of 10%. I would suggest that only properties in areas of Dublin with below average incomes would achieve a gross yield anywhere close to 10%. There is a higher risk of renting properties in low income areas as there is a greater likelihood that a tenant will default on the terms of their tenancy and therefore your projected net yield of 7% may not come to pass.
As always, higher return comes with higher risk. There is no such thing as a free lunch in investing.
Would you finance a purchase at 5% to achieve a net yield of 7% on a risky investment? When you allow for the fact that 25% of interest payments (and LPT) are non-deductible for income tax purposes, you start to see that leveraged rental residential properties rarely (if ever) make sense for ordinary investors in the current environment.