3D - Build Scene

Making my scene in Unity I face some problem but not a lot of them . The problems that I face weren't so much about my terrain but it was when It came to the building part . For me it was a real challenge making a house and creating some roads . The reason why is because when making a house you have to make sure that every wall has to be perfectly lined up or else then house will look weird . And every house that I have isn't lined up correctly so that really bothers me because it makes the house looks weird. And this being my main problem in Unity really sucks because most of my design has houses or buildings in it . So now I think that my design is going to look weird because my houses don't look to good so I really don't know how my game will end up .Some other challenges that I had creating my Unity scene was that sometimes the scene would just not save properly . And that made me make everything I did that day all over again and that really bother me because I would do all that work for nothing .