Projects included the BNZ Building (now State Insurance) at 1 Willis St, the Telecom towers, the former Public Trust Building and the Hunter Building at Victoria University.
More recently he was the director responsible for the T&G Building strengthening in Wellington and the refurbishment of the government-occupied high rise at 33 Bowen St.
Locally, he was the engineer to contract for the Knoll Ridge Cafe on Mt Ruapehu, the DoC Whakapapa Visitor Centre, the sewerage scheme on Mt Ruapehu and the Parawera subdivision at Taupo.
The Smiths moved to Taupo in the early 2000s intending to pursue a semi-retired lifestyle. They bought a boutique bed and breakfast which Mrs Smith ran while her husband did engineering consulting from home and was a Rotary member and founding member of the Taupo Sculpture Trust.
But the Christchurch earthquake brought new challenges and opportunities. Demand for Mr Smith's seismic engineering skills soared and the pair started Ian Smith Project Services Ltd in Taupo (recently re-branded as ISPS Consulting Engineers), which soon outgrew their home and now employs 21 people across Taupo and Wellington.
While Mr Smith was still taking on new projects at the time of his death, Mrs Smith was also still actively involved both in finance and as the "mother" of the firm, who liked to take care of the staff, many of whom were from overseas. ISPS business manager Peter Martyn says the Smiths were a team, generous and loving.
"We were privileged to have known them and to have worked for them."
■Mr and Mrs Smith are survived by six children, 11 grandchildren and one great-grandchild.