Only if you have to, otherwise it is cheaper to work from home. It means less of an initial outlay while everything from the heating, lighting even down to the portion of mortgage interest on the room of the house that you make an office, is tax-deductible. However make sure your mortgage lender agrees to you using your home as business premises, and also you'll need to make sure it's covered under your home insurance.
If you want to keep your home and office separate, then renting a desk in office locally might make sense, and it will keep you working from nine to five.
If you need an office for staff, you should think about whether renting or buying is the way to go. Renting prevents a big initial outlay, and that money can go into the business, plus you can change premises easily as you grow. Remember though, you may be tied into contracts, and could be paying more than you need to in rent. If you own the office building, you can also benefit from property price rises in the future too.
