Since a few years you can borrow up to 100% of the market value (the value according to the valuation report). If however you bought a property for an amount less than the market value in theory you could borrow slightly more. Do realize you will not be entitled to a tax rebate on this extra part as it is not going towards the purchase amount but towards your purchase costs or taxes. Also, if you plan to invest into energy saving measures banks will allow you to finance this up to a maximum of 106% of the market value. They allows this because in turn it will lower your energy expenses.