Working from home can be the cheapest arrangement, especially if you are a freelancer or if you don't have the obligation to go to the office every day. You already have the space, there is no commute, and a quiet morning can be very productive. Renting somewhere else needs to solve a real problem to justify another monthly bill.
Perhaps that problem is a kitchen table you must clear every evening. Perhaps it is a steady stream of calls that nobody else at home should have to listen to. Or perhaps nothing is wrong with working from home, except that having a client there does not suit you.
The useful comparison is between the working week you have and the one you are paying to create. Tax matters, but it comes after that comparison. A deduction will not make an unsuitable office a sensible purchase.
Why should you consider renting an office?
Fewer interruptions, longer focus blocks
An office gives you something a home rarely does: a stretch of time nobody else has a claim on. No doorbell, no one passing through the room, no chores sitting in your line of sight. Demanding work needs long uninterrupted blocks, and that is exactly what a home day tends to break.
The room also does part of the work for you. At home, you are the only one holding the line on focus, and you are also the person who has to answer the door. In a space built for work, everyone around you is there for the same reason; staying with a task takes less effort than defending it.
Space between work and home
When the desk sits beside the dinner table, work never properly ends. The laptop closes, but the unfinished job stays in the room, and so does the reminder of it. A journey home does what no amount of discipline indoors quite manages: it marks the point where the day stops.
There is a second cost, and it is easy to overlook. A spare room given over to a desk is a room your household has lost. You do not need to put a commercial rent on your own bedroom to recognise that you would like it back — and a desk somewhere else is what gives it back.
Receiving clients
A home address does not make a business less professional. A home setting can still make the meeting awkward. Ask what the appointment actually needs: a private conversation, a comfortable place to sit, and no household routine running in the background.
If that comes up once or twice a month, booking a meeting room as needed will cover it. Once appointments become a regular part of your week, booking rooms one at a time turns into its own piece of admin — chasing availability, taking what is free rather than what suits you. At that point a permanent base stops being an upgrade and becomes the simpler option.