If you ask for approval of minor renovations inside your lot, and the renovations don’t affect anyone and don’t have any implications for the common property, and the Committee refuses your request, then as a general guide, that refusal is likely to be considered unreasonable. If the Committee refuses the request because they don’t like you, that is unreasonable. If the Committee refuses the request and they approved a very similar request a short time ago, then that is unreasonable.
When you think about what might constitute unreasonable it can be useful to turn it around and think about what is reasonable, i.e. what might be a good reason for refusing something. If it doesn’t fit into that category it is likely to be unreasonable.