Cost of rebuilding a garage

I have checked with our insurance the cost of rebuilding a single garage and they told me EUR 15.560. I done it by curiosity as we are thinking of building a garage at the back of the house and the quote we had back from the builder is way more than that? it is a normal size garage (without pp), no wiring.required. Is it normal ?

I'm currently building a 20ft * 30ft garage - cavity block wall, cladding roof, plastering, electrics etc should cost around 11K - direct labour - tile/slate roof would probably be 3-4K more