Structural Engineering in Christchurch
Christchurch has rebuilt much of its central city since the February 2011 earthquake, and the way structures are designed here changed with it. The earthquakes showed how buildings behave when strong shaking and liquefaction arrive together, and many owners now ask for structures that can be repaired and reoccupied quickly after an event, beyond the life-safety minimum the Building Code sets. Low-damage systems such as base isolation, rocking walls and buckling-restrained braces became common in the rebuild. The city also has older and heritage buildings that need seismic assessment and, in some cases, strengthening, and a large stock of homes on TC2 and TC3 land where the foundation and the structure have to be designed as one. LDE provides structural design in steel, concrete and timber, seismic assessment of existing buildings and strengthening design for owners, developers, builders and public-sector clients across Christchurch and Canterbury. LDE geotechnical engineers work on the same projects, so the foundation design reflects the ground the building will sit on.
How LDE delivers structural engineering in Christchurch
Structural work in Christchurch splits between new buildings and existing ones. For new work we design in steel, reinforced concrete and timber, and agree seismic performance targets with the client early, since a low-damage system is far easier to include at concept stage than to add later. For existing buildings we carry out initial and detailed seismic assessments, inspect earthquake-damaged structures and design strengthening that suits how the building is used.
It is the same structural engineering capability that supports LDE’s buildings work nationally, with geotechnical and civil input from the wider firm.
- Structural design of commercial, industrial and multi-unit residential buildings
- Initial and detailed seismic assessments of existing buildings
- Strengthening design for older and heritage structures
- Foundation and superstructure design for homes on TC2 and TC3 land
Building consent and seismic design standards in Canterbury
Christchurch City Council processes building consents and administers the Christchurch District Plan, whose heritage schedule affects alterations to protected buildings. Environment Canterbury publishes regional natural hazard information, which we read alongside the city’s flood and liquefaction mapping when setting floor levels and choosing foundations. Every design follows the Building Code and current national standards and guidance.
- New Zealand Building Code requirements for structure (B1) and durability (B2)
- MBIE guidance on repairing and rebuilding houses affected by the Canterbury earthquakes
- Standards New Zealand loadings, concrete, steel and timber design standards
LDE structural engineering in Canterbury
Structural commissions in Canterbury come from a broad client base. Developers need design for apartments, townhouses and commercial buildings in and around the central city, often on sites where deep piles or ground improvement are needed. Building owners and property managers ask for seismic assessments before a purchase, a lease or a change of use, and strengthening design where a building rates poorly. Homeowners and builders on the flat land need foundation and superstructure design that fits the technical category. Industrial clients on the city fringe and in Selwyn and Waimakariri districts need portal-frame warehouses, mezzanines and equipment supports.
Common questions about structural engineering in Christchurch
What is a %NBS rating?
It expresses a building’s expected earthquake performance as a percentage of the new building standard, meaning what a new building on the same site would achieve. A building rated below 34 per cent can be classed as earthquake-prone under the Building Act, and many commercial tenants look for 67 per cent or more. A detailed seismic assessment gives the most reliable rating.
Can a house on TC3 land use a standard foundation?
Usually not. TC3 land needs a site-specific foundation designed from a deep geotechnical investigation, such as a stiffened surface structure that can be relevelled, deep piles or ground improvement under the slab. We design the foundation and the structure above it together so each suits the other.
Do heritage buildings in Christchurch need special treatment?
Buildings scheduled in the Christchurch District Plan need resource consent for many alterations, including some strengthening work. We design strengthening that keeps as much heritage fabric as practical and prepare the structural information the heritage assessment and consent will ask for.
Who leads LDE’s Christchurch structural work?
Chartered Professional Engineers from our team, supported by LDE specialists nationally.
