For the most part, i aree with Audible solutions but disagree that you can't make money on big jobs. We do the occasional small 15k-50k job but the overwhelming majority of our jobs are in the 100k-400k range. If you can pre-empt the likely problems, have the expertise to properly design and install the systems to a high standard, have a large enough team to comlete the work in a timely fashion, have enough cashflow to see you through the odd final payment delays, have a bullet proof contract, have the ability to devote 400+ man hours to a job and still service other clients and the ability to quote acordingly for all the above, then you can make good money on big jobs.

If you can't achieve ALL of the above then it's quite possible you could lose your house in the attempt. The big jobs may seem glorious if your not doing them but the risks are much bigger as well if your unprepared for the reality of doing them.

Simon.