Revit

Isolated Footing Family in Revit: Build, Parameterize, Place

Build an isolated footing family in Revit 2027 from Metric Structural Foundation: EQ-locked planes, size, depth and material, then place it under columns.

  • TS. Nguyễn Mạnh Tuấn
  • 14 min read
An isolated footing built from a home-made family, placed under a steel column in Revit 2027 Photo: Screenshot of Revit 2027

Structural engineers spend a surprising amount of time hunting for a CAD file of a pad footing or a spreadsheet for one more project. In Revit the job is done once: a parametric footing family where three numbers make a new footing, reusable on every project that follows.

An isolated footing family in Revit starts from the Metric Structural Foundation.rft template. First you draw four reference planes around the centre and drive them with dimensions labelled Length and Width. Then you build the pad with an Extrusion locked to those planes, attach thickness and material to parameters, flex the family, load it into a project and drop it under columns with At Columns. This article walks all 15 steps in Revit 2027 with a screenshot at each stage. If you want to learn content creation properly, the Institute runs a Revit Family course.

What goes into a Revit footing family and why build your own

A reinforced concrete pad footing usually has three parts: a blinding layer, the pad itself, and a pedestal linking the pad to the column. The pad is the part worth turning into a family, because it repeats at every grid intersection and differs only in length, width and depth. Blinding is normally modelled as a thin foundation slab, and a pedestal can be added to the same family the same way the pad is built.

The content that ships with Revit does not match your office's footing details. Building your own once gives you three things a CAD file never will: resizing from one input box, concrete volume flowing straight into schedules, and a host that accepts reinforcement.

Getting ready to create a foundation family in Revit

You need Revit 2027 with the metric family templates. The footing template sits in the English folder of the Family Templates set; the exact path depends on the installation and is shown under Options › File Locations. You also need a project with structural columns to test the footing; placing columns is covered in structural columns in Revit.

The general mechanics of parametric families, type versus instance parameters and formulas, are covered in how to create a family in Revit. This article sticks to what is specific to foundations. If Revit is new to you on the structural side, start with what is Revit Structure.

Open the template and set the model behaviour

Step 1 — Open the Metric Structural Foundation template

Go to File › New › Family. The New Family - Select Template File dialog opens in English-Imperial, the inch-based set. Do not press Open yet: type the path of the English folder into File name, press Enter to switch folders, then type Metric Structural Foundation.rft and click Open.

1 the English folder holding the metric templates. 2 the footing template name. 3 Open Photo: Screenshot of Revit 2027

Step 2 — Recognise the Family Editor

The screen switches to the Family Editor with a short tab list: Create, Insert, Annotate, View, Manage, Add-Ins, Modify. The Properties palette reads Family: Structural Foundations, so the template already carries the right category and Family Category needs no change.

1 the Forms panel on the Create tab. 2 the Structural Foundations category. 3 the four elevations Back, Front, Left, Right Photo: Screenshot of Revit 2027

The Ref. Level plan is where plan dimensions go. The Front elevation is where the depth goes.

Step 3 — Set Material for Model Behavior to Concrete

In Properties, under Structural, Material for Model Behavior defaults to Other. Open the list, pick Concrete and click Apply.

1 Material for Model Behavior. 2 the five choices Steel, Concrete, Precast Concrete, Wood, Other Photo: Screenshot of Revit 2027

Beginners skip this more than any other step. Autodesk's About Reinforcement page is explicit: a valid rebar host is a family whose Material for Model Behavior is Concrete or Precast Concrete. Leave it at Other and the placed footing will not take reinforcement.

Step 4 — Look at the three built-in parameters

On the Create tab, Properties panel, click Family Types. The template already defines Structural Material and three dimensions, Foundation Thickness, Length and Width. Type name is blank because the family has no type yet.

1 Type name still blank. 2 Structural Material. 3 the template's three size parameters Photo: Screenshot of Revit 2027

Reuse these exact names instead of inventing local ones: schedules and other tools recognise the standard names. Click Cancel.

Build the reference frame and lock the dimensions

Step 5 — Draw four reference planes around the centre

Open the Ref. Level plan. The template has two reference planes crossing at the centre, and that crossing is the insertion point when the footing is placed. Click Create › Datum › Reference Plane and draw two vertical planes either side of the centre and two horizontal ones above and below it. Exact positions do not matter yet.

1 the Modify, Place Reference Plane context tab. 2 Is Reference of a new plane is Weak Reference. 3 the temporary dimension while drawing Photo: Screenshot of Revit 2027

Revit 2027 no longer has an Options Bar; the Offset box for drawing a plane at a distance sits on the Draw panel of the ribbon.

Step 6 — Dimension a three-point string and click EQ

Type DI. Pick the left plane, the centre plane and the right plane, then click in empty space to place the string. Select the string and click the struck-through EQ symbol above it: both segments become equal and the symbol turns into EQ. Repeat in the other direction.

1 the EQ toggle of the selected string. 2 the horizontal string already equalised. 3 the vertical string selected Photo: Screenshot of Revit 2027

EQ keeps the footing centred however wide it grows. Only a three-point string offers EQ; a two-point dimension does not.

Step 7 — Add overall dimensions and label them Length and Width

Add one overall dimension between the outer planes in each direction. Select the horizontal one and the ribbon switches to Modify | Dimensions. On the Label Dimension panel open Label: the list has a search box and exactly the template's three parameters. Pick Length. Do the same for the vertical dimension with Width.

1 the Modify, Dimensions tab. 2 the Label list with its search box and three parameters. 3 the Label row in Properties. 4 the selected overall dimension Photo: Screenshot of Revit 2027

A labelled dimension shows its parameter name, as in Length = 1520, so you can tell at a glance which dimensions drive the geometry.

1 the two EQ strings. 2 Length labelled. 3 Width labelled Photo: Screenshot of Revit 2027

Model the pad with an Extrusion

Step 8 — Sketch the pad and lock all four edges

Click Create › Forms › Extrusion. The ribbon changes to Modify | Create Extrusion; choose the rectangle tool on the Draw panel and pick two opposite corners on the plane intersections. Right after drawing, each edge shows an open padlock; click all four to lock the edges to the planes.

1 the Depth box, 304.8 by default. 2 Extrusion End and Extrusion Start. 3 a closed padlock Photo: Screenshot of Revit 2027

Locking decides whether the family works at all. Unlocked, the solid sits in the right place on the day you draw it, but change Length and the planes move while the solid stays put.

Step 9 — Flip the solid below Ref. Level

While still sketching, read Properties: Extrusion End 304.8 and Extrusion Start 0.0, so the solid grows upwards from Ref. Level. A footing needs the opposite, top of pad at Ref. Level and the body below it. Set Extrusion End to 0 and Extrusion Start to a negative value such as -500, click Apply, then the green tick on the Mode panel.

Step 10 — Drive the material from a parameter

With the new solid selected, the Material row in Properties has a small button at its end. Click it; the Associate Family Parameter dialog lists compatible parameters. Pick Structural Material and click OK.

1 the Material row and its associate button. 2 the Structural Material parameter Photo: Screenshot of Revit 2027

The Material row turns grey with an equals sign: the solid's material now follows the parameter, so one change updates every solid.

Step 11 — Lock the depth in the Front elevation

Open the Front elevation. Draw a horizontal reference plane below the solid. Type AL, pick the new plane, then the bottom edge of the solid, and close the padlock that appears. Dimension from the Ref. Level line down to that plane, select the dimension and label it Foundation Thickness as in step 7.

1 the labelled thickness dimension. 2 the bottom plane locked to the underside. 3 Ref. Level at the top of the pad Photo: Screenshot of Revit 2027

From now on the pad depth is set by two planes, not by the Extrusion Start value.

Flex the family, load it and place it under columns

Step 12 — Create the first type and pick a material

Open Family Types, click the new type button beside Type name and name it after its size, for example 1500x1500x500. Enter 500 for Foundation Thickness and 1500 for Length and Width. Click the Structural Material cell, click the button at its end to open the Material Browser, choose Concrete - Cast-in-Place Concrete and click Apply.

1 the first type named after its size. 2 the concrete material. 3 the three sizes Photo: Screenshot of Revit 2027

Structural Material is a type parameter, so in the project you can still switch it to your office concrete through Edit Type.

Step 13 — Flex with a larger type

Add a second type 2400x1800x600, enter its values, click Apply and OK. Go back to the Ref. Level plan.

1 Length changed to 2400. 2 Width changed to 1800. 3 the pad follows the planes and stays centred Photo: Screenshot of Revit 2027

The planes move, the solid follows, both EQ strings stay balanced: the family passes. Check in plan and elevation, because in 3D a small footing and a large one look almost the same. Try one absurd set of values too, to be sure the family fails clearly.

Step 14 — Save and click Load into Project

Save the family with a plain ASCII name such as MONG-DON-CN.rfa. Click Load into Project on the Family Editor panel. With several projects open, Revit asks through the Load into Projects dialog; tick the target project and click OK.

Revit switches to the project and goes straight into the placement command, with the context tab Modify | Place Isolated Foundation.

1 the Modify, Place Isolated Foundation tab. 2 At Grids and At Columns. 3 the family and type just loaded. 4 the top and bottom elevations of the footing Photo: Screenshot of Revit 2027

Properties immediately shows Elevation at Top 0.0 and Elevation at Bottom -500.0: the footing sits below its placement level by exactly its depth, thanks to steps 9 and 11.

Step 15 — Place footings under columns with At Columns

Pick the right type in the Type Selector. Click At Columns on the Multiple panel; the context tab becomes Modify | Place Isolated Foundation > At Structural Column and the status bar asks for columns. Select one or more columns and click Finish. Revit puts one footing under each column, with the top of the footing at the column base. Both At Grids and At Columns are also described on Autodesk's Create an Isolated Foundation page.

1 the Reinforcement panel with Rebar, Path, Morphed. 2 the home-made footing family. 3 top and bottom elevations. 4 the footing under the column Photo: Screenshot of Revit 2027

Select the placed footing and the context tab already carries a Reinforcement panel: the footing is a valid rebar host. Reinforcing it is covered in column and footing reinforcement, and pulling out its concrete volume in concrete quantities in Revit.

Structural foundation family: three options worth knowing

Pedestal. Add a second Extrusion with its own set of reference planes around the centre, its own EQ and labels, following steps 5 to 11. Keep the top of the pedestal where the column base lands, since At Columns puts the top of the family at the column base.

Is Reference. A newly drawn plane is Weak Reference by default. Setting the centre planes and the two outer faces to Strong Reference makes dimensions and alignment in the project snap to them first. Do not give too many planes a strong reference.

At Grids. This button drops footings at the intersections of the selected grids, useful when foundations come before columns. It is greyed out in 3D views.

When the footing family misbehaves

SymptomCauseFix
Every size comes out as an odd decimalBuilt from a template in English-ImperialRebuild from Metric Structural Foundation.rft in the English folder
Length changes but the solid stays putSketch edges never locked to the planesSelect the solid, Edit Extrusion, lock the four padlocks
Footing floats above its levelExtrusion still runs from 0 up to 304.8Set Extrusion End to 0 and Start negative, then lock the underside as in step 11
The Label list lacks the parameterParameter not defined in Family TypesCreate the Length parameter first, then label
EQ cannot be clickedThe dimension has only two referencesDimension a three-point string through the centre plane
Warning None of the created elements are visibleThe footing lies below the plan's view rangeOpen the foundation plan or edit View Range
At Columns then Finish creates nothingThe column already has a pile cap below itPick columns without a foundation, or remove the old one first
No Rebar button on the footingMaterial for Model Behavior is still OtherChange it to Concrete in the family and reload

Five things people get wrong

What people sayWhat Revit 2027 actually does
Labels are set on the Options Bar2027 has no Options Bar; Label sits on the Label Dimension panel of Modify, Dimensions
New Family opens the metric templatesIt opens English-Imperial; the metric set is in the English folder next to it
Any family can host rebarOnly families whose Material for Model Behavior is Concrete or Precast Concrete
A footing Extrusion grows downwards by itselfIt grows upwards 304.8 by default; set a negative Start or lock the underside to a plane
After loading you must find the placement commandLoad into Project drops you straight into Place Isolated Foundation

In short, an isolated footing family in revit is four jobs in order: a plane frame with EQ and labels, an Extrusion locked to that frame, depth and material tied to parameters, and a flex test before loading. Once that is done, every new footing is just another type in Family Types.

Frequently asked questions

Which template should a Revit footing family use?

Use Metric Structural Foundation.rft. It already carries the Structural Foundations category and the four parameters Structural Material, Foundation Thickness, Length and Width.

Do I really need Material for Model Behavior?

Yes. Left at Other, the footing cannot host rebar; set it to Concrete as soon as the template opens.

Can this family model an eccentric footing?

Yes, but drop EQ in the eccentric direction and use two separate dimensions from the centre to each edge, each with its own label.

How do I place many footings at once?

Select several columns after clicking At Columns, or use At Grids to fill every intersection of the selected grids.

About the author

TS. Nguyễn Mạnh Tuấn — BIM lecturer at the Institute of Construction Informatics – Hanoi University of Civil Engineering