UP ON THE ROOF - PART 2

Last time we were up here on the roof, all our cares just seemed to drift right into space. Suddenly ,we get a reality check - what's wrong with this footprint roof - it's just not generating the roof shape we want or expect !

Well the problem stems from a feature that was introduced in Revit 7 that allowed adjoining sides of a footprint roof to have different eaves heights. A side effect of this new functionality was that roofs may not generate the shape you want.

Here's our floor plan.

FLOOR PLAN.

Nothing particularly special there.

Here's the sketch of the proposed footprint roof.

ROOF FOOTPRINT SKETCH.

And here's the roof generated from that sketch ( in Revit Building 8.1 )

ROOF 3D INCORRECT.

The plan below shows the roof form , with clouds highlighting the junctions which don't conform to our required design.

ROOF PLAN - INCORRECT.

This is what we were hoping to get.

SKETCH OF DESIRED ROOF PLAN.

Using this sketch as a base, we can generate the roof that we want.

First delete the old incorrect roof.

Now we need to analyze the geometry of the proposed roof. Looking at it, it would seem possible to create it as two pieces of roof.

We construct the first piece using pick walls and slope lines and then pick the sketch lines for the valleys, hips and ridges.

The first part of the roof now looks like this.

PART A OF THE PROPOSED ROOF.

Now, we'll make the second part the same way.

Now we just need to use Join Geometry for the two parts, and here's the roof we wanted.

CORRECT ROOF 3D.

It's taken more effort than a " normal " footprint sketch, but in the end ...

On the roof, it's peaceful as can be

And there the world below can't bother me

Let me tell you now.