I give this little independent flick a lot of credit for investing in character development. It would have been more typical for there to be rivalry or infighting among the three siblings - in other words, boring, cliched melodrama. Instead, there is quite a lovely sense of loyalty between the two brothers and their little sister. In addition, the three leads are quite good actors, and I expect as they gain experience will become excellent.
Cons include the performance of the actress who plays Hannah, the oldest brother's science partner. Granted, she doesn't have much to work with, but she delivers most of her lines in monotone, lifeless fashion. Also, about 1:16 minutes into the movie it becomes somewhat preposterous and certainly too melodramatic. Finally, the last con is the atrocious anonymous pop song that plays over the last few minutes of the movie. Completely unnecessary, and really ruins the last few scenes the characters have together. It's the kind of thing we often see in John Hughes movies. Perfectly fine and expected in a 1980s teen comedy-drama, but a real non-sequitur in this kind of movie, not to mention passe.
That said, Our House is worth watching for fans of supernatural thrillers and ghost flicks. There is nothing original here, but the script is stronger than usual, and the filmmakers and cast were clearly invested in the project.