New Zealand's structural steel industry has joined others in expressing concerns about building height restrictions proposed in inner city Christchurch. In its submission to the draft Central City Plan, Steel Construction New Zealand (SCNZ) notes that of the 181 tragic fatalities caused by the February earthquake, none occurred in buildings over seven storeys high.

Alistair Fussell, a structural engineer and Manager of industry group SCNZ, says that despite the good performance of modern steel-framed buildings in the earthquakes, such as the now-reoccupied 12-storey HSBC Tower, there appears to have been a loss of confidence in multi-level construction.

"While concerns about building heights are understandable given the terrible loss of life and devastation caused to the city, restricting building heights certainly won't encourage building owners to invest and rebuild in Christchurch.

"Christchurch should allow higher buildings, but build them using appropriate materials and technology. New low-damage, seismic-resisting steel systems developed here in New Zealand will make multi-level buildings economically feasible for Christchurch developers and building owners - and safe for their tenants."

Mr Fussell also says the challenging soil conditions in the CBD mean that expensive foundations will be required to help minimise building damage during a severe earthquake. These foundation costs will be relatively more expensive when spread over a limited number of floors.

The other key issue SCNZ highlighted in its response to the draft Plan is the use of local suppliers and content in the rebuild.

"Local companies should be given a fair opportunity to compete for rebuild work through appropriate procurement practices that consider whole-of-life costing. New Zealand's vibrant structural steel industry is well-placed to provide high-quality materials which meet stringent Building Code requirements."

Mr Fussell says decision-makers should be doing everything they can to encourage developers and owners to stay and invest in Christchurch, and embracing the latest low-damage seismic-resisting technology will help.

Mr Fussell says his industry is in the early stages of developing a rating system for steel-framed buildings which will allow the seismic performance of different earthquake load-resisting systems to be assessed and compared. The rating system will allow developers and owners to make informed building decisions, leading to lower insurance premiums and higher rental incomes - not to mention a smaller carbon footprint as a result of increased longevity - for their buildings.