Seismic assessment
Initial Evaluation Procedure (IEP) and Detailed Seismic Assessment (DSA) to NZS 1170.5 and the Engineering Assessment Guidelines. We issue %NBS ratings that councils and insurers accept without review.
Structures that outlast the next earthquake.
01 · Our expertise
Seismic assessment, heritage strengthening, and multi-storey commercial design.
Meridian Structural Engineers is an independent Wellington consultancy founded in 2011. We specialise in buildings that carry risk — heritage facades that must survive the next fault rupture, multi-storey towers that need to meet NBS targets before the deadline, and new commercial builds designed for IL3 and IL4 importance levels. Every senior engineer holds CPEng and at least one has walked through every project before a line is drawn.
Heritage strengthening
Base isolation, steel moment frames, FRP wrapping, and post-tensioned rocking walls — chosen for minimum visual impact on protected facades. Heritage New Zealand Category I and II experienced.
New-build commercial
Multi-storey concrete, structural steel, and mass timber for office, retail, and mixed-use. Foundation design on Wellington's variable ground — greywacke, marine clay, reclamation fill.
02 · Case studies
Three buildings, three problems, three outcomes.
Former BNZ Building, Lambton Quay
15% → 80% NBS1930s reinforced concrete heritage building. Base isolation retrofit with lead-rubber bearings, supplemented by new steel moment frames behind the original facade. Building remained partially occupied during works.
Thorndon Apartments, Tinakori Road
47 units · 8 storeysNew-build residential tower on a confined site. Post-tensioned concrete flat-slab structure with a central shear core. Foundation on driven steel piles to greywacke at 18m. Wind analysis for the Tinakori Hill venturi effect.
Karori School Hall
Community-fundedTimber portal-frame hall replacing a quake-damaged block building. Glulam beams, plywood diaphragm, rocking timber walls. Co-designed with the school board and funded by a community trust grant.
03 · Credentials
Independent, qualified, insured.
| Credential | Held by | Details |
|---|---|---|
| Chartered Professional Engineer (CPEng) | All 4 senior engineers | Practice fields: Structural Engineering, Fire Engineering (Dr Chen) |
| International Professional Engineer (IntPE) | Dr Sarah Chen, Marcus Te Whare | Washington Accord reciprocal recognition |
| SESOC membership | Firm-wide | Structural Engineering Society of New Zealand |
| WCC pre-approved reviewer | Dr Sarah Chen | Wellington City Council independent peer review panel since 2018 |
| Professional indemnity | Firm | $5,000,000 PI insurance through Marsh Ltd |
| Heritage NZ advisor | Marcus Te Whare | Advisor for Māori meeting house structural conservation |
04 · The team
Four engineers, forty years combined.
Dr Sarah Chen
Director · CPEng, IntPE, PhDPhD in structural dynamics from the University of Canterbury. 18 years practice. Led 40+ heritage strengthening projects including the former BNZ building and Antrim House. WCC peer review panel member.
Marcus Te Whare
Senior Engineer · CPEng, IntPESpecialist in timber engineering and Māori meeting house restoration. 12 years practice. Heritage New Zealand advisor. Designed the Karori School Hall and three whare restoration projects in the Wairarapa.
Priya Kapoor
Senior Engineer · CPEngMulti-storey commercial and residential. Formerly Beca Wellington. Led the Thorndon Apartments structural design. Experienced in post-tensioned concrete and seismic isolation.
James Aldridge
Engineer · ME(Hons), working toward CPEngCanterbury graduate, 4 years practice. DSA assessments, foundation design, and construction monitoring. Runs all site observation for the firm.
05 · Fee calculator
Hourly or fixed — see which suits.
Estimate your project cost
Hourly estimate
$10,600Fixed package
$12,50006 · FAQ
Questions we get asked.
What is %NBS and why does it matter?
%NBS stands for percentage of New Building Standard. It rates how a building would perform in a design-level earthquake compared to a new building. Below 34%NBS is legally earthquake-prone, and councils can issue notices requiring strengthening within set timeframes. We assess and issue %NBS ratings that councils accept.
Do I need a seismic assessment?
If your building was designed before 1976, is unreinforced masonry, or has received a council notice, you almost certainly need one. Insurers and tenants increasingly ask for assessments on pre-2004 buildings too. An IEP takes two to three weeks and costs from $3,200.
What is the difference between IEP and DSA?
An Initial Evaluation Procedure (IEP) is a desk-based screening that gives a preliminary %NBS rating, usually within ±10%. A Detailed Seismic Assessment (DSA) involves opening up walls, testing materials, and running a full structural model. A DSA is required when an IEP result is marginal or when you need a rating for strengthening design or building consent.
How long does building consent take in Wellington?
Wellington City Council's statutory timeframe is 20 working days, but complex commercial projects routinely take 30–40 working days. We prepare RFI-ready documentation and have a direct line to the WCC structural team, which helps avoid multiple rounds of requests for information.
Can you work with our architect?
Always. We work alongside architects from concept through to construction monitoring. We are familiar with most Wellington practices and have standing relationships with Studio Pacific, Athfield, and Warren and Mahoney. We also undertake independent peer review for other engineering firms.
07 · Contact
Start a project enquiry.
For urgent seismic enquiries — post-earthquake inspections, red-stickered buildings, or council deadline responses — call the office directly. We aim to have someone on site within 24 hours for Wellington CBD buildings.
Independent practice. We do not sell construction services, so our advice is always in your interest.