Later alterations

Why it is easier than in traditional construction

• partitions are easy to remove and build,
• because of the service cavity, the cabling can be reached without opening up the structure,
• the screwed connections can be undone,
• and the structure is light, so there is less demolition waste too.

Why care is still needed

Because you cannot tell by looking what a wall does.

Three questions have to be settled before any intervention:

1. Is it load-bearing

If so, removing it means breaking the load path. Load-bearing and non-load-bearing walls.

2. Is it part of the bracing system

The less well-known danger: a wall can be important without carrying any vertical load. Removing a shear wall affects the stability of the building. Designing a shear wall.

3. What runs inside it

Cables, service routes, fire stopping, cavity barriers.

What cutting an opening involves

Not only the members removed:

• a lintel is needed above the opening,
• a jamb beside it,
• the continuity of the bracing can be broken,
• the continuity of the vapour control and fire-rated layers has to be restored.

That is a designer’s task, not an installer’s. Openings and lintels.

What must not be forgotten on the fire side

If the intervention affects a fire-separating element, the seals have to be restored. Fire stopping opened up and not repaired is the quietest loss of protection there is. Fire stopping of penetrations.

The role of documentation

An alteration is as simple as the documentation is good:

• a plan showing the load-bearing and bracing walls,
• the build-ups,
• the service routes,
• photographs of the concealed work.

With those, designing an alteration is a matter of hours. Without them a survey is needed — and a survey means opening up.

The point

A framed structure adapts well, but only with the information to hand. Keeping the documentation here is directly measurable in money.