Basement Floor Plan
A basement floor plan works around what is already there: the stair, support columns, the furnace and the plumbing. Its overall size is fixed by the house above, so the job is dividing that footprint into rooms that suit the light and headroom. This page covers zoning ideas, room sizes, the rules to check first and how to draw a basement as a floor below your plan. The example is a 7 × 9 m (24 × 30 ft) open basement.
An open basement with zones
Drawn to scale. The links open this room with the same furniture, ready for you to add doors and windows and resize anything.
Typical sizes for basement rooms
| Metric (typical) | Imperial (typical) | Fits | |
|---|---|---|---|
| Family or media room | 4.5 × 6.0 m | 15 × 20 ft | Sofa, chairs, TV, a games table |
| Guest bedroom | 3.0 × 3.6 m | 10 × 12 ft | Double bed and wardrobe |
| Laundry and utility | 2.4 × 3.0 m | 8 × 10 ft | Washer, dryer, sink, counter |
| Storage | 1.8 × 2.4 m | 6 × 8 ft | Shelving on two or three walls |
Start with what is already there
Before drawing any room, mark the fixed things: the stair, columns and beams, the furnace or boiler, the water heater, the electrical panel, drains and any windows. They decide where walls can go and which areas suit a bedroom, a family room or storage.
Measure the headroom at the lowest points, under beams and ducts, as well as the general ceiling height. A space that is fine for storage can be too low to count as a habitable room.
Basement layout ideas
The overall size is set by the house above, so a basement plan is about dividing that footprint.
Open family room
Keep the main area open and use furniture to form zones, as the example plan does; add columns with C where yours stand.
Utilities together
Group the furnace, water heater, laundry and storage in one corner, near the existing plumbing.
Guest suite
A bedroom and shower room at the end with the brightest windows and an exit outside.
Home gym or workshop
A hard-wearing room away from the bedrooms above, near the utilities.
Stairs, windows and light
The stair position shapes the whole floor. A stair in the middle divides the basement into two natural zones; a stair at one end leaves a long open space that suits a family room with storage at the far end.
Basement windows are usually small and high, so put the rooms people spend time in, the family room and any bedroom, where the windows are, and the storage, laundry and mechanical room in the darker parts. A walk-out basement with a door to the garden is the obvious place for a guest suite.
Rules to check first
In the US, the International Residential Code (IRC) generally asks for a ceiling height of at least 7 ft (2.13 m) in habitable basement space, with allowances for beams and ducts, and for an emergency escape and rescue opening, an openable window or door to the outside, in a basement with habitable space and in every basement bedroom. Local versions of the code differ, and other countries have their own rules, so check before you plan a bedroom down there.
Leave access around the furnace, water heater and electrical panel; their installation instructions usually state the clear space needed in front of them.
Basement items in the library
Default library sizes. Columns and stairs come from the editor’s tools rather than the furniture library.
Sofa
210 × 90 cm (6′ 11″ × 2′ 11″). The anchor of a family room.
TV stand
160 × 45 cm (5′ 3″ × 1′ 6″). Keep it away from the glare of high windows.
Washer
60 × 60 cm (2′ × 2′). Add the Dryer beside it for a laundry corner.
Counter
180 × 60 cm (5′ 11″ × 2′). A folding counter for laundry, or a workbench.
Bookshelf
90 × 35 cm (2′ 11″ × 1′ 2″). Shelving for a storage room.
Single bed
90 × 200 cm (2′ 11″ × 6′ 7″). For a guest room or a playroom sleepover corner.
Storage and the floor above
A basement is usually the home’s main storage, so give it a proper room with shelving rather than leftover corners. Keep a clear route from the stair to the storage and to the mechanical room for servicing.
Think about the rooms above: a home gym or a TV room under a bedroom carries noise up, and a new bathroom is easiest under an existing one or near the main drain.
Common basement planning mistakes
Boxing in the mechanical room
The furnace, water heater and panel need space to work on and replace them. Plan the room around that, not the other way round.
A bedroom without an exit
A bedroom with no escape window or door may not meet local rules, and is unsafe in a fire.
Ignoring low beams
A beam or duct across a room can make it feel low or break up a ceiling; mark them on the plan.
Losing the light
Walls that cut the windows off from the main room make the whole basement darker.
Plan your basement in the editor
Add a floor below
In your house plan, use Add floor below so the basement sits under the ground floor; or open the example on its own.
Set the height
With nothing selected, the properties panel shows the floor’s floor-to-floor height; type yours so the 3D view matches your headroom.
Place stairs and columns
Use the stair tool (S) and the column tool (C) to mark what is already there.
Divide and furnish
Draw walls with W to create rooms; each enclosed room gets its own area automatically.
Templates, guides and tools for a basement
- Villa template with a stairTwo floors joined by a stair, to see how levels work.
- Home floor plan makerMap your existing home floor by floor before you plan changes.
- How to measure a roomThe measurements to take, in order, including awkward spaces.
- Plan one basement room in the room plannerOne space at a time, drawn to scale with its furniture.
- Floor area calculatorAdd up several rooms, such as every zone of a basement.
Frequently asked questions
Can I draw a basement below an existing floor plan?
Yes. Use Add floor below in the floors list. The new floor sits under the ground floor in 3D, and the floor above shows faintly in 2D so you can trace its outline.
Can I show support columns?
Yes. The column tool places rectangular or round columns; type their size in the properties panel.
Can I plan a basement bedroom?
You can draw one, but check the local building rules first: they often require minimum ceiling heights and an escape window or door.
How do I work out the area of a finished basement?
Each enclosed room shows its area in the properties panel, and the area schedule lists every room and the total for the floor. Areas are measured to wall centre lines.
What should go near the stairs?
Usually a shared space, such as the family room, so nobody has to walk through a bedroom or storage room to reach the rest of the floor.