UIButton setImage not working

Please check your button type.

If your button type is "System" you should change it to "Custom"

Two things to do here:

#1, change your code to:

[button1 setImage:[UIImage imageNamed:@"house.png"] forState:UIControlStateNormal];

and #2

make sure your UIImage returns a valid image.

In other words,

UIImage * imageToSet = [UIImage imageNamed: @"house.png"];
if(imageToSet)
{
    [button1 setImage:[UIImage imageNamed:@"house.png"] forState:UIControlStateNormal];
} else {
    // if you see this line in your console, then you know where to look for a problem
    NSLog( @"why is my image object nil?");
}