Most of what makes a house feel big is decided on the drawing
Not in the furniture. Window height, ceiling shape, where the walls are and what is built into them all get settled before anything is manufactured, and they are expensive to revisit later.
Draw the eye upward
That is the mechanism behind almost every piece of advice on this subject. Tall windows reaching close to the ceiling, a vaulted ceiling, built-ins that run high, curtains hung at ceiling height: all of them do the same thing, which is make the mind read a space as larger than its floor area.
Understanding that is more useful than a list, because it tells you which decisions are worth spending on.
Four decisions that change how big a house feels
These are the ones worth arguing about before manufacturing, because none of them is straightforward to change once the house exists.
Window height, more than window size
Both size and placement matter, and the larger the room the more natural light it needs. Main living spaces want the widest glazing.
But the height is what does the work. Windows reaching nearly to the ceiling force the eye upward, and that single move makes a room read as larger without changing its dimensions at all.
A vaulted ceiling, if the trusses are right
The most direct way to draw the eye up. A vault in a living room, dining room or primary bedroom is the first thing anyone notices walking in, and the room feels considerably larger while its floor area stays identical.
It is also cheaper than most people assume when designed in rather than added. Scissor trusses produce a vault without the cost of a parachord system, and because trusses are manufactured to your specification it is a drawing decision rather than a structural rebuild.
Let furniture define spaces instead of walls
Leave the main living areas open to one another and use furniture and rugs to mark where one space ends and the next begins. A sofa with its back to the kitchen defines a living room as clearly as a wall does, and the house reads as one connected space rather than a collection of segregated rooms.
A wall you do not build is also a wall you do not pay for, along with its framing, drywall and finishing. That is a real saving and it is rarely mentioned in advice about open plan.
Build the storage in, do not furnish it later
Built-in furniture uses every available inch, which leaves more open air in the room. Built-in bookshelves in a living room give the space character and storage at once, and if they run high they draw the eye up as well.
The underlying problem is that most people underestimate how much storage they need, and clutter is what makes a room feel small. Planning it into the drawing is the difference between a house that stays open and one that fills up.
What you can still change afterwards
All of it works, none of it needs deciding now, and none of it costs anything to reverse. Which is exactly why it should not be competing for attention with the four above.
Keep the colours light
White opens a room best, and pale tones do most of the same work if you want colour. Darker accents are fine; a room you want to feel open should not be weighed down by deep walls.
Hang a mirror, and aim it
A large framed mirror adds depth like nothing else. The part people skip is deciding what it faces, since it should be reflecting a view or a piece of art rather than a corridor.
Furniture that holds things
Pieces that double as storage keep the floor clear, and a clear floor is most of what makes a room feel large.
Curtains at ceiling height
Hung high rather than at the window head, they extend the vertical line and reinforce whatever the windows are already doing.
Space and design
Drawing the eye upward. Tall windows reaching close to the ceiling, vaulted ceilings, built-ins that run high and curtains hung at ceiling height all do the same thing: they make the mind read the space as larger than the floor area suggests. It is the single mechanism behind most advice on this subject.
It can, because a wall you do not build is a wall you do not pay for, along with its framing, drywall, finishing and sometimes its structure. The caveat is spans: removing a wall that carries load means engineering the beam that replaces it, which costs. Open plan tends to pay off in smaller footprints and needs checking in larger ones.
Less than most people assume, if it is designed in rather than added. Scissor trusses produce a vaulted ceiling without the cost of a parachord system, and because they are manufactured to your specification the vault is a drawing decision rather than a structural rebuild. Adding a vault later is a different and much more expensive job.
Paint colour, mirrors, furniture and how you use awkward corners. Everything else on this page, the window sizes and placement, the ceiling height, the wall positions and the built-ins, is decided at the drawing stage and difficult or expensive to revisit afterwards.
Related pages
Ask about the ceiling before you order the trusses.
Vaults, window heights and wall positions are all cheap to change now and expensive later. Design, estimating and engineering are included in the package rather than billed separately, so raising it costs nothing.