I've just finished putting together the 4Ground damaged detached house. The construction is similar to the standard detached house but is a little fiddlier in places due to the additional damaged elements (the extra exposed brickwork for example) although not dramatically so. The set comes with some additional slates, bricks and floorboards which you can use to scatter over the floors.
Overall I think the finished house works really well and I have only one small gripe. 4Ground have their website URL printed on one of the components. It's the same with the standard house; however, in the standard house you can't see it - this isn't true for the damaged one and it does slightly detract - so I'll be doing some covering up there.
Here's the angle which shows the offending advertising:
And finally alongside the standard house: