How to Measure and Draw a Floor Plan to Scale

An accurate floor plan drawing is a necessity whether you're planning a home remodel, commercial space build-out, or just need dimensions for arranging furniture placement.

Here are a few tips on how to measure and draw a floor plan to scale.

1. Determine the Level of Accuracy Required

If you're a real estate agent or appraiser and your floor plan drawing is simply to measure the approximate size of the building and show the general interior layout, you don't need to be overly accurate. Measuring within the nearest 1/4 or even 1/2 foot of outside walls is probably sufficient.

When space planning an interior remodel, such as a kitchen, you will want to be more precise. If you're simply drawing a preliminary plan to give to a contractor, measure to the nearest 1/4 inch. The contractor is going to measure again before ordering materials, so your drawing can be "close enough." If you're doing the work yourself, then be as accurate as possible - measure to the nearest 1/16 inch.

2. Start by Measuring the Perimeter

Look at the room (or outside of the building, if you're taking exterior measurements) and make a rough outline of the dimensions, so you have a good visual starting point. Measure the longest wall first. Do this by running your tape measure along the baseboard from one corner to the other. Run the tape along the top of the baseboard so you get a full wall-to-wall dimension. If this is impractical, run it along the floor and make an adjustment for the width of the baseboards. For outside walls, simply go from one corner of the building to the other.

Repeat this process for the remaining walls. Don't worry about door openings at this point. What you want is an accurate measurement of the full wall dimensions.

Hint: If you're using US/Imperial measurements, it's easier to use inches rather than a combination of feet/inches and use decimals instead fractions. For example, if your wall is 10' 6-1/2" long, use 126.50 inches. The reason is that it will be a lot easier for you to check your math later.

Once you get the perimeter of the room (or building) measured, check your math to make sure the dimensions close. If they don't, your measurements aren't accurate and you need to check them again. Also, make sure to note the orientation (north, south, east, and west) of the room on your drawing.

Floor plan outline

3. Measure Doors and Windows

From the nearest corner, measure the distance to the door opening and note this on your drawing. Ignore casings or trim. Measure the width of the door. Note the direction that the door swings and show this on your drawing with an arc. Now measure the width of the casings around the door and note those on your drawing.

Measure windows from frame edge to frame edge, without the casings or trim. Depending on the purpose of your floor plan drawing, you may want to also measure the height of windows and their distances from the floor and ceiling.

Rather than trying to write all of these on your diagram, use the back of the page as a door/window schedule. Letter or number doors and windows on your plan, then note the various dimensions and notes on your schedule.

4. Measure Other Features

Fireplaces, cabinets, built-in bookshelves, and any other features should be measured and added to the plan next. If your plan includes multiple rooms, make sure to account for the interior and exterior walls. Typical residential construction uses 6" exterior and 4" interior walls.

It's also a good idea to measure and locate electrical switches and outlets, thermostats, circuit boxes, radiators, heating and air conditioning registers, and any other elements on your diagram.

5. Measuring for Elevation Drawings

A floor plan is an overhead view of a space. An elevation is a ground-level view of a wall. If you need elevation drawings, you'll want to do these on separate sheets of paper. Measure each wall from floor to ceiling, and use the wall-to-wall measurements you already have. Draw the perimeter of the wall. Label it so you'll know which wall is which: e.g., Kitchen: North Elevation."

Draw in all of the doors, windows, cabinets, switches, etc. on each wall elevation.

6. Drawing a Floor Plan to Scale

Once you have all of your measurements and have made a rough sketch of your floor plan on paper, it's time to create your scale drawing using SmartDraw. See how to draw a floor plan with SmartDraw.

Floor plan perimeter