Yes, most interior designers archive their previous projects so that their clients can refer to them and understand the quality of work they can expect.
Generally, interior designers for home take three months for smaller projects. However, the larger projects can take up to one year. However, you can always contact and ask a professional interior designer about duration.
Interior designers design spaces like apartments, offices, restaurants, old and new constructions, etc. Many designers are also known to provide interior design services for salons, lavish mansions, resorts, corporate buildings, and so on.