www.ultimatehandyman.co.uk

Sketchup can do what you can make it.....it's a bit down to your time, skill and patience!

It can be mm perfect for designs, it can do 3d renderings and flybys - but only if you have the patience/slill to learn it. Lots of videos on youtube and some books are available too.

Can imagine someone who is good at it being onsite with a camera and laptop and helping mock up designs.

BG

sketchup definitely is only as good as the person using it,
takes a bit of time to get up to speed with how it works.

but for a free, 3d design & layout software, can't get better

I have the file for the shell of the building here, supplied by the frames manufacturer, I'm now working on the interior arrangements. I only hope the planners have caught up with my 21st century housing needs.