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The Question & Answer (Q&A) Knowledge Managenet

The Internet has many places to ask questions about anything imaginable and find past answers on almost everything.

Table of Contents

- What is a free plan in architecture?
- What are ordering principles?
- Is the well ordering principle an axiom?
- What is a datum in design?
- What are the types of datum?
- How do I choose a datum?
- What is a datum line?
- What is an example of a datum?
- How is chart datum calculated?
- How do you get a datum point?
- How do you read a RL plan?
- What is a datum level in construction?
- What is a RL in construction?
- How do you calculate RL levels?
- What is the difference between RL and FFL?
- What is RL height?
- What is SSL and FFL in construction?
- What is FFL plan?

In **architecture**, a **free plan** is an open **plan** with non-load-bearing walls dividing interior space. In this structural system, the building structure is separate of the interior partitions.

These 6 **ordering principles** include axis, symmetry, hierarchy, datum, rhythm, repetition, and transformation. When experiencing forms and spaces in a building, you can be assured that at least one, if not all of these **ordering principles** were employed by the building designer.

In mathematics, the **well**–**ordering theorem**, also known as Zermelo’s **theorem**, states that every set can be **well**–**ordered**. … The **well**–**ordering theorem** together with Zorn’s lemma are the most important mathematical statements that are equivalent to the **axiom** of choice (often called AC, see also **Axiom** of choice § Equivalents).

**Datum**: A **datum** is a form which ties together or anchors all other elements of the **design**. It can be a line, like a road with houses arranged along its length, a flat plane, or even a 3D space. Many buildings all share a plane which acts as a clear **datum**— it’s the ground on which they are built! Ordering Principles.

There are two main **datums** in the United States. Horizontal **datums** measure positions (latitude and longitude) on the surface of the Earth, while vertical **datums** are used to measure land elevations and water depths.

**Datums** are important and care must be taken when **selecting** them. They must be easily identifiable on the part. When parts are symmetrical or have identical features that make identification of **Datum** Features difficult, the **Datum** Features should be physically identified.

Noun. **datum line** (plural **datum lines**) (engineering) A **line** which serves as a reference or base for the measurement of other quantities.

An **example of a datum** is the assumed altitude of a specific piece of land used as the basis in calculating the altitude of the top of a mountain on the land. A point, line, or surface used as a reference, as in surveying, mapping, or geology.

**Chart Datum** is the plane below which all depths are published on a navigational **chart**. It is also the plane to which all tidal heights are referred, so by adding the tidal height to the charted depth, the true depth of water is **determined**.

Creating a **datum point** by projecting a **point** onto a face. Select a **point** on the model and an edge or **datum** axis on which to project the **point**. Abaqus/CAE creates the **datum point** where the edge or **datum** axis intersects a line that is normal to it and passing through the selected **point**, as shown in Figure 7.

The levels on the site **plan** are the numbers next to the crosses on the site **plan**. They look like this: The cross marks where the level was taken on the site with the equipment, and the number is the height. If you look at the site **plan**, on the bottom left of the corner of the site is the level 10.

On a **construction** project, a **datum level** is an arbitrary horizontal plane of reference from which all vertical dimensions are measured. It can show the vertical height difference between floor **levels** of a **building** as well as differences in **levels** between one part of the site and another.

From Wikipedia, the free encyclopedia. Relative level in surveying refers to equating elevations of survey points with reference to a common assumed datum. It is a vertical distance between survey point and adopted datum plane.

Once you have taken all the **levels** you want, you will need to **calculate** the actual height values, or reduced **levels** (**RL**) by subtracting each one from the instrument height (IH). This gives you the ‘real’ height of the ground at the base of the staff.

I don’t see it that often but engineers and surveyors use **R.L.** for Relative Level or Reduced Level. … It is a measurement of height taken from some known datum. **F.F.L** is First Floor Level.

Reduced level (**RL**): this is the **height** or **elevation** above the point adopted as the site datum for the purpose of establishing levels. To establish the required depths for a drainage system you need to work from the datum point.

Correct me if Iam wrong, **FFL** refers to the level at the top surface of floor finish. … SFL refers to the level at the top surface of the floor screeding or concrete topping. While **SSL** refers to the level at the top surface of the structural slab.

The floor **plans** will also have the finished floor levels (**FFL**) on them so the builder knows how high above natural ground (NGL) the house is to be.