Always build your dollhouse according the steps in the instructions or you might end up not being able to fit walls and floors.
This particular dollhouse has a lot of interlocking parts which basically lock the assembly together. This means you need to be extra careful assembling in the right order or you will have a very hard time trying to disassemble parts to fix them.
The best way to interlock parts is by slanting them sideways so they can slide in place. Of course, this is wood and it will not slide easily, so you will need the help of a mallet to push parts along. Be very gentle and tap with enough force to make the parts move into place only. You will have to fit tabs into slots as you go along in order for the parts to continue moving and not snag. It will take some patience to do this. I imagine it is a little easier to do this with this smaller half scale model than it would with the bigger scale one, since you can turn the dollhouse different angles in order to make parts fit.
Since the dollhouse has not been painted, it should make the fitting of parts easier than if the wood was swollen with moisture.
There are two key things to keep in mind when assembling this particular shell.
1. Only glue when the instructions tell you to. If you glue ahead of time and then stop the assembly, letting the glue dry, it will be virtually impossible to finish. The dollhouse needs leeway and movement in order to fit all of the walls in place.
2. Be careful with the mullions. You want to try and stay away from them as they are very fragile and can easily break if you try to fit parts while pressing against them. Make sure you are aware of where your fingers are as you apply pressure to make parts fit.
This dollhouse does not have any inaccessible areas in the main shell assembly so you can fit all of the walls into place, including the back ones, without having to finish anything first. Make sure you place the correct walls on the correct sides so your dollhouse roof can be installed properly later on. Use the internet and my pictures as a guide.
As you can see these little half scale dollhouse are extremely cute and detailed.