After the insulation was finished (horrah!) the next step was pouring a 1.5 inch layer of concrete flooring onto the main floor. We did this to help provide sound insulation between the suite and us, and the garage and us. Stef was understandably nervous -- you can't really watch the concrete going down, as there are few vantage points to watch from, and if it winds up bumpy or slanted then it's a nightmare. But all went well -- apparently it's smooth as a baby's bottom, and a lot more level than one.
Sound insulation is an interesting thing. The concrete, apparently, is excellent at damping out air-transmitted noise (like music or voices), but does nothing to stop footfalls from resonating through our floor down into the suite below. On the garage side of the house, this isn't important: we only want to stop the noise of drilling, sawing and pounding in the workshop from wafting upwards into my office. No one cares if the sound of me typing / throwing my computer to the floor in frustration (or more likely little Freya throwing her toys about) penetrates into the 'quiet sanctum' (ha ha) of the garage. On the suite side, however, though we are now protected from noise by them (unless they dance on their ceiling), they are not yet protected from noise by us. Stef plans to suspend their ceiling on little metal brackets that apparently helps to deal with this. We don't want to be too too precious about our tenants, but from experience we know that sound transmission can be the thing that drives away otherwise-perfectly-good paying customers.