Mängel sind in BE u.a. defects; vgl.

http://www.proinspect.co.uk/tag/hidden-defects/

Vorschlag: taking into account the defects ( ich würde ergänzen, falls zutreffend : "die sich bei der Besichtigung zeigten")

we can only offer you ninety per cent of the asking price

Danke und Grieße nach Wien!

Considering all (of) the defects, ...

Dude, ist dein Vorschlag eine Alternative, oder findest du "taking into account" falsch? (Just wondering ...)

Mit 'taking into account' verbinde ich einen größeren Denk- und "Rechen"prozess als mit "considering" (klingt nach einfachem 'angesichts'...).

It was meant more as an alternative, Raudona, perhaps a more widely used alternative.

..and for another alternative:
Given the defects....

In AE, considering and given would probably be used more; taking into account is certainly right.

I think we like to keep things less 'wordy', and the nuance in difference is not great enough to be significant. (you have to think just as much for considering something as for taking it into account) :) :)

Given the defects, we can only offer you ...

What #7 says also applies in BE. "Taking account.." is not a phrase I would personlly use in this context.