OK I googled but I am no wiser - what sort of file is .dwg and how do I view it?

[KatyMac]

Thanks

It might be something to do with plans or buildings?

That seems very reasonable. It sounds like your plans are coming together

I guess

I have put in about £3k for my fire escape - do you think that is realistic?

It will be just a basic metal staircase, and the knocking through the wall....so that sounds a reasonable amount, but you should be able to get a quote from a local blacksmiths/metalworker. I think again you can get "off the shelf" stairs that are modified to suit, and companies that do a design and build service.

Thanks