The floor or house plans are at the heart of your construction project. These drawings help you visualise the space even before its built. Since these illustrate your future home, it’s important that you know how to read them.
The problem? Floor plans have symbols and patterns that are confusing at first glance. This makes first-time builders and renovators feel perplexed and anxious.
Fear not! Because in this blog, we’re going to tell you the meaning of the symbols and patterns in your complex planning drawings. This way, you will know exactly what you’re getting and paying for.
This is the second part of our Guide to Reading Floor Plans. If you wish to know the different types of planning drawings and their purpose, read the first part of the guide here.
Familiarise yourself with symbols and patterns in your house plans
Basically, the lines represent the walls of the building and the space in between the lines is the floor. The breaks in the walls indicate where the doors, windows, and room openings are.
But, planning drawings are highly detailed documents. It shows exactly what kind of wall, flooring material, window, door, and opening to build. That’s when the symbols and patterns come into the picture.
Here are the symbols you can find on your house plan. We grouped these so it’s easier for you to understand:
The walls are the strongest visual elements in a floor plan. Walls are represented by lines and may be solid, filled with a pattern, or with no fill. Deciphering each one is not that as hard as you think.
Thick lines represent structural walls. Notice that the lines representing the exterior walls are thicker than the interior walls. These are the first walls to build in the project. These play a huge part in the house’s structural integrity.
The weight and thickness of the lines also express the distance of the element in the space. Plans are either vertical or horizontal slice-through of the structure. Heavy lines are used in walls that are cut in a section or floor plan, while lightweight lines indicate that the item is distant.
On a renovation, the thickness and weight of the line help you spot an existing wall from a new one. Existing walls often appear as a chunky line filled with solid black or grey colour. (We call this hatch.) The new walls appear as two parallel lines with no fill or filled with a pattern that tells you the material it’s made of. Here’s a quick legend for you:
House plans always have a drawing legend. Check yours to be sure.
The symbol for a regular, single-hinged door is a straight line that’s perpendicular to a wall. There’s a curved line that indicates how the door opens — right, left or both. Here are various types of doors:
There are symbols for every kind of door available on the market. There’s one for pocket doors (hidden into the walls) and barn doors (slides over the wall). See diagram below:
Windows are easy to spot. It’s a break in the wall connected by thin parallel lines. These lines represent the glass sandwiched by the frames. Casement windows may or may not have an arc which shows the direction where the window opens. See above and below photo for the symbol.
Getting familiar with the doors and windows are important when reading and visualising a floor plan. Take time to understand how it opens, the location, and the size. Keep these factors in mind because it helps in furniture placement.
Staircases are illustrated using a series of parallel lines, with arrows that go up or down. When the arrow goes down, there’s a floor underneath. Here are some staircase designs:
Some residential floor plans will show expected flooring whether it’s tile, wood, or stone. This also helps you get a grip of the floor pattern. Here are some examples:
These symbols are pretty straightforward. You can recognise each one once the first time you saw it. Building designers use these symbols on the floor plan so you and the builder can perceive the use of the room. This is also proof that all items initially planned on paper truly fits the space.
When there’s a change in ceiling height, the building designer labels it using dashed lines. Looking at a floor plan, you and your builder can’t identify how much the ceiling dropped. You need to look at other drawings (particularly the section) to know more.
Another feature that’s labelled on the floor plan is the fireplace. It is usually illustrated with a smaller rectangle (firebox) inside a larger rectangle (exterior wall of the fireplace or chimney). Sometimes, the building designer makes it more obvious by using a shape that looks like a fireplace.
Gridlines on House Plans
These dashed lines are important for the builder. They create coordinates which help the builder measure and build the structure in the right location. These lines also help builders communicate during the construction phase. So, when the lead builder refers to the “wall along grid line A”, everybody will look at the exact same thing. There’s less confusion in the team.
Designers always do a simple cross-referencing system between their planning drawings. These references lead to detailed drawings, consultant drawings, and other key documents (fittings and fixtures schedules, specifications, general finishes schedule). This system enables the designer to communicate the plans to the builder in the most detailed way. It helps them understand the details of the design.
As we all know, building designers work with other specialist consultants when building a project. Referencing the consultant’s report or drawing will help the builders construct that specific part of the house.
Here, the designer wants the builder to check out the house plans specified in image F in page A.09 to find out how to build the connection between the wall and roof. When you reach that page, you’ll find a scaled drawing that will guide the builder when constructing this part of the house.
Referencing is necessary for both small and huge projects. It’s most useful in large ones, where there’s a need to cross-reference the drawings with one another.
When a change is made to the construction drawings, the designer draws a squiggly revision bubble around the change. Then it’s labelled with a letter or number that leads them to the exact description of the change. These descriptions are listed within the title block or drawing label with the date when the change was made.
Revision bubbles have to stand out so the builders notice the changes in the design. It’s also a record of the number of times the design was updated. Most designers allow a few changes for free on your house plans. The exceeding revisions requested by the client becomes an additional fee.
Other elements worth knowing about
- Elevation markers: A circle with two numbers which refers to the sheet number and the drawing number on that sheet. It has a triangle which indicates the viewing direction.
- Section markers: Looks similar to elevation markers but with a line. This line shows where the building has been cut through to expose a particular section drawing.
- Finished floor level or FFL tag: Located near the middle of a room on a floor plan and shows the level of the finished surface relative to the Australian Height Datum (AHD: sea level) or another nominated level. Often the ground FFL will be nominated at 0.00 metres high, with all other levels relative to this.
- Material tags: Use to cross-reference back to separate document with a list of legends that tell all the materials to be used in a build.
- Relative-level markers: Like to FFL tags, these markers show the height of an element relative to AHD or a nominated level.
- Dimension markers: Used to show the measurements of each element in the drawings.