We are a new shed at startup and have been quoted £300-£400 by Zurich for £5M public liability and theft/damage insurance on £5k contents does that seem reasonable? Has anyone any better ideas, Whilst I know its anecessity, it seems a shame to look for grants to pay insurance when we could put the money to much better use.
If you have an opening window, you could make up a board which fits/clamps in the window space and carries the extract pipe. Then you can remove it at the end of a session and close the window.
You might also think about putting the dustiest machines in a partitioned and ceilinged enclosure with general extraction or best of all look for an old wet back spray booth so all the dust gets pulled into a wet curtain