One room, two jobs: the spare room that has to be an office and a guest room
The spare room is the most over-asked room in a British house. It is expected to be a home office five days a week, a guest bedroom four nights a year, and quite often a place to keep the ironing board as well. The reason these rooms rarely work is not that they are small. It is that a desk and a bed want opposite things, and nobody has made them negotiate.
A desk wants daylight from the side, a solid wall behind the screen, and a socket within reach. A bed wants a clear route in, space to make it, and a surface on at least one side. Put both in without thinking and you get a desk jammed into a corner with your back to the door, and a bed you have to climb over.
Here is how I work through it.
Start with the bed, not the desk
This surprises people, because the desk is the thing you use every day. But the bed is the bigger object and it has the least flexibility, so it sets the plan.
Three honest options:
A sofa bed. Works when the room is genuinely used as an office and guests are rare. Check the open depth before you buy anything: a double sofa bed usually needs about 200 cm of clear floor in front of the wall it sits against, and you still need roughly 60 cm to walk past it. If the room is under 300 cm in that direction, a sofa bed will block the room whenever it is open, which may be perfectly fine four nights a year.
A wall bed. Better than its reputation, and the right answer more often than people expect. Closed, a good one is about 40 cm deep, which is shallower than most sofas. Open, allow about 210 cm out from the wall. The catch is that the wall it fixes to has to be sound, and the floor in front of it has to stay clear, so a rug with a heavy table on it is out.
A daybed. The quiet winner in narrow rooms. About 90 cm deep, sits against the long wall, works as seating all week and a single bed when needed. If your guests are usually one person, this is often the most civilised answer.
Then give the desk what it actually needs
A desk of 120 x 60 cm is comfortable for most people. You can go to 100 x 50 cm without it feeling mean, but below that you are working on a shelf. Behind the chair, allow 90 cm to push back and stand up without hitting anything. Against a wall, a depth of 60 cm lets a monitor sit far enough away to be kind to your eyes.
Put the desk side-on to the window if you can. Facing the window means glare on the screen; backing onto it means glare behind your head on calls. Side-on solves both, and it is the single change that improves more home offices than any piece of furniture.
Storage: shallower than you think
The instinct is a wall of wardrobes. In a room this size, 60 cm deep joinery along one wall will take about a fifth of the floor and make the room feel like a corridor.
Shelving at 35 to 40 cm deep holds books, files, folded clothes and most of what a guest arrives with. Take it to the ceiling rather than out into the room. If guests do need hanging space, a 60 cm deep section of 60 to 80 cm wide is enough for a weekend, and it can be one small part of an otherwise shallow run.
The guest test
Before I sign off a layout, I run it through four questions. A guest should be able to:
Put a suitcase down, open it, and leave it open.
Hang up two things without moving anything of yours.
Reach a light switch from the bed.
Put down a glass of water and a phone, and charge the phone.
If the plan fails any of these, it is not a guest room. It is an office with a bed in it, and people can tell.
What has to go
Honesty matters more than cleverness here. A room of about 10 square metres can hold a desk, a bed and sensible storage. It cannot also hold a wardrobe for out-of-season clothes, a clothes airer, an exercise bike and the Christmas decorations. Something has to move elsewhere in the house, and deciding that at the drawing stage costs nothing. Deciding it after the joinery is fitted costs a great deal.
Lighting, briefly
Two circuits make the difference between a room that switches roles and a room that does not. A bright, cool working light over the desk, and a warmer, lower light for the bed. One overhead bulb doing both jobs is why so many spare rooms feel like a meeting room at night.
If you are planning one
This is exactly the kind of room Online Design suits. It is one room, the walls are staying put, and the whole problem is layout, storage and light. Send me the measurements and photographs and I will draw it properly, at scale, before anything is bought.