Renovation and extension

Why the technology suits

Little additional load

The reserve of the existing foundations and structure is limited. A light structure often fits within it.

Dry technology

No concreting, no curing time, no mass moisture — it can be built while the building is in use.

Fast site work

The members are made in advance and erection is short.

Little space needed

On a tight plot, beside an existing building, that is decisive.

The real difficulty

Not the new structure but:

Getting to know the existing one

Geometry, structural system, condition, capacity, foundations. The old drawings are not enough. Surveying an existing building.

The junction

Where the new and the old structure meet:

• different stiffness: the two systems move differently,
• different tolerances: the old building is less accurate,
• different building physics: the continuity of the vapour control layer and the insulation is hardest at the junction,
• differential settlement: the new part may sit on different foundations.

These junctions have to be designed specifically — there is no standard solution here.

The faults of the existing building

An extension often brings the old building’s problems to the surface: damp, poor foundations, earlier alterations.

Kinds of extension

Lateral extension

A separate structure with a movement joint at the junction — generally the cleanest solution.

Rooftop addition

Here the capacity of the existing building decides. Rooftop additions.

Loft conversion

With a light structure the additional load is minimal.

Internal alteration

Framed partitions, transfer structures, rearranging internal spaces.

The energy angle

An extension often affects the energy position of the whole building — and it is a good opportunity to renew the insulation of the existing part too.

The point

The difficulty of an extension is always on the existing side. The new structure is the easier task — the junction and the survey are what take engineering.