City of London street scene at the Bank junction, with the domed Royal Exchange building, modern office towers and a red double-decker bus

03 — Existing Buildings

Existing Buildings & Adaptive Reuse

Assessment and alteration of existing structures, including change of use, strengthening, extensions and retrofit — helping buildings meet present-day needs without unnecessary demolition or rebuilding.

What this covers

Most buildings can do more than they are currently asked to do. Adaptive reuse starts with an honest structural assessment of what exists, then finds the least invasive way to unlock a new use, layout or performance standard.

Change of use

Structural assessment and strengthening to support a building's conversion to a new use — residential, commercial or mixed.

Strengthening & upgrading

Targeted strengthening to support new loads, floor openings or additional storeys, working with what already exists.

Retrofit-first strategy

Structural options that favour repair and adaptation over demolition, informed by embodied carbon as well as cost.

Vertical extension

Assessment of an existing structure's capacity to support additional storeys, and the design to deliver it.

Demolition is a last resort, not a default

We treat demolition as the option to justify, not the option to default to. In our experience, a genuinely thorough structural assessment usually finds more latent capacity in an existing building than a first look suggests — capacity that can unlock a scheme without the cost, disruption and embodied-carbon impact of rebuilding.

Where new structure is genuinely required, we design it to sit alongside and work with what already exists, rather than overriding it — keeping intervention proportionate to the change actually being asked of the building.

Illustration of a modern glazed extension integrated with a historic stone tower

Local coverage

Adaptive reuse engineering across London & Kent

London's adaptive reuse instructions are often office and warehouse conversions to residential or mixed use; in Kent, the same question more often concerns barns, oasts and other agricultural buildings finding a new life. We advise on the reuse and adaptation of existing buildings from our offices in London and Kent, serving projects across the UK and internationally, assessing what a structure can genuinely support before assuming rebuild is the only option. Where a building is listed or historically significant, this work is led by our Conservation Accredited (CARE) engineers.

Frequently asked questions

Can an existing building always be reused instead of rebuilt?

Not always, but it's worth testing properly before ruling it out. A structural assessment often reveals more usable capacity than expected, and the embodied-carbon and cost case for retention is usually strong.

Do you work on change-of-use conversions?

Yes — assessing an existing structure against a new use's loading and layout requirements, and designing the strengthening needed to support it, is a regular part of this work.

What about adding an extra storey to an existing building?

This depends on the existing structure's foundations and frame capacity, which we assess directly rather than assuming. Where capacity is limited, we look at strengthening or load-reduction strategies before assuming a scheme isn't viable.

Discuss an existing building project.

Discuss a project