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Wellington asks more of a building than most of the country does — wind that drives rain into every joint and flashing, steep sections that load up pole foundations and retaining walls, and a housing stock that has been standing on these hills for a century or more. A builders report from Alert is how you find out how a particular property has coped with it.
Alert’s inspectors are trade-qualified and still practising as builders. They work through every accessible area of the property — subfloor and foundations, framing, cladding and roofing, interior linings, joinery, drainage and the site itself — and moisture-test wherever Wellington’s weather makes it matter, in accordance with NZS 4306:2005.
Call 0800 4 ALERT or book online, and we'll give you a firm price for the property.
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24-48 Hour Report Delivery Guaranteed
Looking for a Building Inspector in Wellington? Our trade-qualified inspectors provide thorough building reports within 24-48 hours, combining speed with meticulous attention to detail. A pre-purchase building inspection helps protect you.
Our Wellington building inspection service is perfect for time-sensitive property purchases. Each inspector carries professional indemnity insurance and brings deep knowledge of Wellington's local market and common building challenges, including wind-damage assessment, hillside stability concerns, earthquake-strengthening requirements, and weatherboard deterioration in the region's coastal climate. All inspections comply with NZS 4306:2005 standards for comprehensive, reliable assessments.
"House inspection" and "building inspection" mean the same thing. If you are buying a home in Wellington, this is the report you need — a trade-qualified inspector, on site, assessing the property in person.
On the day, the inspector works through the property in a set order: the exterior and roof first, then the roof space, then the interior, and finally the subfloor wherever it is accessible. In Wellington that last step usually decides it. Much of the city is built on a slope, and it is underneath the floor — in the piles and pole foundations, the retaining walls holding the section up, and the drainage meant to carry water away from both — that you find out whether a house is still sitting where it was built, or has been quietly moving for years.
The exterior tells the other half of the story: wind-driven rain works its way into cladding junctions and flashings long before a damp patch shows on the inside of a wall. One thing worth knowing before you book: a house inspection is not a valuation. They do different jobs — a valuation assesses market value, a house inspection assesses condition — and your lender may require both. Buyers often assume one covers the other.
Call 0800 4 ALERT or book online for a firm quote based on your property address.
Wellington presents a unique combination of building challenges. Extreme wind exposure, steep hillside terrain, active seismic faults, driving rain, and a housing stock that ranges from 1880s wooden villas to post-earthquake modern construction all combine to make a professional building inspection essential for anyone purchasing property in the region.
Understanding what makes Wellington different helps buyers appreciate both the risks and the rewards of buying in the capital.
Wellington is one of the windiest cities in the world, and its buildings bear the brunt of that reputation every winter. Southerly storms regularly bring gusts exceeding 120 kilometres per hour, and exposed hilltop and ridgeline suburbs experience wind speeds that test even well-constructed buildings. The constant wind loading accelerates the deterioration of roofing materials, lifts flashings, loosens fixings, and drives rain horizontally into building envelopes at angles that would never cause problems in more sheltered locations.
Our inspectors assess every Wellington property with wind exposure in mind. We check the condition of roofing fixings and ridge capping, the integrity of flashings at roof-to-wall junctions and around penetrations, the condition of cladding seals and joints on the windward faces of the building, and the performance of windows and doors under pressure.
Properties in the most exposed locations — including suburbs like Kelburn, Brooklyn, Mount Victoria, Karori, and the south coast — receive particular attention because the wind loading on these buildings is significantly greater than on sheltered valley-floor properties.
A large proportion of Wellington's residential properties are built on steep hillside sites. The city's topography forced early developers and subsequent generations of builders to construct homes on slopes that would be considered challenging or marginal in most other New Zealand cities. This creates a range of specific inspection priorities that flat-land properties simply do not face.
Retaining walls are a critical focus in hillside Wellington inspections. Many properties rely on multiple retaining structures to create building platforms, access ways, parking areas, and garden terraces. We assess the condition, adequacy, and drainage provisions of all retaining walls, looking for signs of movement, leaning, cracking, or outright failure.
Timber retaining walls from the 1970s and 1980s are frequently at or past the end of their serviceable life. Concrete block and poured concrete walls can develop cracks over time, particularly when drainage behind the wall is inadequate and hydrostatic pressure builds during wet weather.
Site drainage on steep Wellington properties is also more complex than on flat sites. Water from rain and surface runoff needs to be managed carefully to prevent it from accumulating against foundations, undermining retaining walls, or saturating the hillside and contributing to slope instability.
Our inspectors assess the adequacy of site drainage systems, including guttering, downpipe connections, surface water channels, and subsoil drainage, and note any areas where water management appears insufficient for the site conditions.
Wellington sits on or near several active fault lines, including the Wellington Fault, which runs directly through the city. The seismic risk is real and ongoing, and it directly affects the property market. Under the Building Act, buildings that are assessed at less than 34% of the New Building Standard (NBS) are classified as earthquake-prone, and their owners are required to strengthen or demolish them within specified timeframes.
For residential property buyers, a building's seismic status is a critical consideration. Our inspectors note any visible indicators of seismic vulnerability — including unreinforced masonry construction, heavy concrete or brick chimneys, unreinforced concrete block walls, and buildings on soft or reclaimed ground.
We also recommend clients check whether the property has an earthquake-prone building notice, which can be verified through the national register. For apartment buildings and multi-unit properties, seismic strengthening requirements can involve substantial body corporate levies, so understanding the building's seismic status before purchase is essential.
Wellington's housing stock tells the story of the city's development, from the earliest wooden villas through to contemporary earthquake-resistant construction. Each era brings characteristic building methods, materials, and common defects that our inspectors are trained to identify.
Wellington's inner suburbs — Thorndon, Mount Victoria, Aro Valley, Newtown, and parts of Island Bay and Kilbirnie — contain large numbers of wooden villas and cottages built between the 1880s and 1930s. These homes are typically constructed from native timber framing with rusticated or lapped weatherboard cladding, and many have been standing for well over a century. Native timbers are naturally durable, but age and Wellington's demanding climate take their toll.
Common issues in Wellington's pre-war housing include borer infestation in native timber framing, particularly in damp subfloor areas with poor ventilation. Many of these hillside properties have minimal ground clearance on the downhill side, creating chronically damp conditions beneath the floor.
Foundation systems vary from concrete piles to original stone or brick supports, many of which have shifted, deteriorated, or sustained damage over decades of seismic activity. Multiple generations of renovation work — of highly variable quality — are common in these character homes, and assessing how different eras of construction interact within the same building is central to a thorough inspection.
The mid-twentieth century saw significant residential development across Wellington's outer suburbs, the Hutt Valley, and Porirua, including substantial state housing programmes. Properties from this era are typically single-storey, three-bedroom homes built with timber framing, weatherboard or fibrolite cladding, and concrete tile or corrugated steel roofing. Many are constructed on concrete slabs or piled foundations.
These homes are now 50 to 80 years old, and original components are reaching the end of their useful life. Our inspectors commonly find roofing at or past replacement age, aluminium joinery with perished seals and corroding frames, asbestos-containing materials in cladding, soffits, and interior linings, and insulation that is absent or well below current Healthy Homes standards.
In the Hutt Valley, where much of this era's housing is concentrated on the valley floor, subfloor moisture and ventilation issues are particularly prevalent due to the high water table and limited airflow in sheltered locations.
Wellington was significantly affected by the leaky building crisis, and the city's challenging weather exacerbated the consequences. Properties built between approximately 1988 and 2004 with monolithic cladding systems fall within the highest-risk bracket. Wellington's driving rain, high winds, and steep terrain combined to expose weathertightness failures more aggressively than in many other locations.
The hillside suburbs were especially hard hit. Properties on exposed sites experienced wind-driven rain penetrating cladding at angles and intensities that flat-land buildings never faced. Many Wellington homes from this era also featured complex multi-level designs on steep sites, creating numerous junctions, penetrations, and transitions where water ingress could occur.
Our inspectors allocate additional time to properties from this era, carrying out extensive moisture testing at every penetration point and at high-risk details. The very high and extra high wind zone classifications that apply across much of Wellington mean that cladding attachment and waterproofing details need to meet particularly stringent standards — and not all properties from this era achieved that.
Properties built after the 2016 Kaikōura earthquake reflect both updated building code requirements and a heightened awareness of seismic performance in the Wellington region. Modern Wellington homes are typically designed with specific seismic detailing, current weathertightness standards, and building code provisions that address the region's extreme wind exposure. These properties are generally well-built, but they are not immune to quality issues.
Our inspectors find that even recent Wellington builds can have incomplete flashings, drainage connections that are not properly made, and finishing defects that suggest the pressures of a busy construction industry. For townhouse and apartment developments, we also assess inter-tenancy separation, shared drainage systems, and whether the building's seismic design has been properly executed.
A pre-purchase inspection of a new Wellington home provides independent verification that the property has been built to the standard required for its location.
Wellington's climate is the single biggest factor in building deterioration across the region, and understanding how the weather affects buildings helps buyers appreciate what our inspectors are looking for and why certain issues are so common.
Standard rainfall is manageable for most building envelopes. The problem in Wellington is that rain rarely falls vertically. Strong winds drive rain horizontally, and sometimes upward, into cladding joints, under flashings, around window frames, and through any gap or imperfection in the building envelope.
This means that weathertightness details that would perform adequately in a sheltered location can fail in Wellington because they are tested by water arriving from directions and at pressures the design may not have anticipated. Our moisture testing focuses on the windward faces of buildings and the junctions where wind-driven rain is most likely to enter.
Wellington's humidity, combined with its cooler temperatures, creates conditions where condensation is a chronic issue in many homes. Cold surfaces — including single-glazed windows, uninsulated walls, and concrete floors — attract condensation when warm, moist indoor air meets them. Over time, persistent condensation leads to mould growth, timber decay, and deteriorating interior linings.
Our inspectors assess ventilation adequacy, insulation levels, and heating provision as part of every Wellington inspection, because these factors directly influence whether a home will be dry and healthy or chronically damp.
Properties in Wellington's coastal suburbs — including the south coast, Lyall Bay, Island Bay, and the eastern bays from Oriental Bay through to Eastbourne — are exposed to salt-laden air that accelerates corrosion of metal components. Roofing, flashings, guttering, fixings, and aluminium joinery all deteriorate faster in coastal locations. Our inspectors assess the degree of coastal exposure and determine whether metal components are appropriate for the environment and are maintained at a frequency that prevents premature failure.
Every property tells a different story. Here are some anonymised examples from recent inspections our team has carried out across Wellington, showing the kinds of issues we identify and why a professional building inspection matters.
A beautifully presented three-bedroom villa on a steep hillside site, extensively renovated with a modern kitchen and bathroom. The renovation was cosmetically impressive, but our inspection found that the junction between the original villa and a later lean-to addition at the rear lacked visible weatherproofing — no flashing, no building paper transition, just a painted butt joint between two different cladding materials.
In the subfloor, which had less than 300mm clearance on the downhill side, we found active borer in several native timber bearers and floor joists, with significant cross-section loss. The subfloor was visibly damp, with no ground moisture barrier and only two small ventilation openings serving the entire underfloor area.
We recommended borer treatment, replacement of bearers where damage was most severe, installation of a ground moisture barrier, and additional ventilation. The buyer used our report to negotiate a $35,000 price reduction.
A two-storey family home with monolithic plaster cladding on an exposed hillside site. The property had been well-maintained with regular exterior painting, and the vendor believed there were no weathertightness issues.
Our moisture testing identified elevated readings at three locations — the upper-level balcony-to-wall junction, a south-facing window head on the upper storey, and the base of the cladding on the exposed western elevation, where ground clearance was insufficient. The wind exposure on this site was significant, and the driving rain from the prevailing southerly direction was reaching areas of the building that would not normally be at risk on a sheltered flat-land site.
We recommended a full invasive moisture investigation. The subsequent investigation confirmed timber decay behind the cladding at two of the three locations, with estimated remediation costs of $160,000.
A solid three-bedroom family home on a flat valley-floor site, representative of the large volume of post-war housing in the Hutt Valley. The property appeared to be in reasonable condition externally, but our subfloor inspection revealed chronic moisture issues.
The subfloor space had standing water in several areas, the ground moisture barrier was torn and incomplete, and multiple floor joists showed signs of fungal decay. The concrete tile roof, original to the house, had significant deterioration — cracked and broken tiles, degraded bedding on ridge caps, and corroded flashings at the chimney and roof penetrations.
We also identified suspected asbestos-containing materials in the soffit linings and textured interior ceiling coating. Our report enabled the buyer to understand the full scope of work required and to make a realistic assessment of whether the purchase price justified the investment needed to bring the property up to a sound condition.
A relatively new two-bedroom townhouse in a small development. The buyer assumed that a property this recent would have no significant issues. Our inspector found that the boundary fencing between the subject property and the neighbouring unit was not constructed to the height or specification shown on the building consent drawings.
The bathroom extractor fan ducting terminated in the roof space rather than exhausting to the exterior. One downpipe at the rear of the property was not connected to the stormwater system, discharging water directly against the foundation. The inter-tenancy wall had a gap at the junction with the roof framing, compromising fire separation.
Each issue was straightforward to remedy, but collectively they represented construction shortcuts that should have been identified during the original building inspection.
Our report gave the buyer the evidence needed to request that the developer address these items before settlement.
A verbal building inspection starts at $299 plus GST, and a full written pre-purchase inspection and report starts at $499 plus GST. The property is the main factor, so you will know the price before you commit. For more detail on what drives it, see building inspection costs explained.
Wellington has one cost driver most regions do not: terrain. A steep right of way, a house cut into a slope over several levels, a subfloor with limited clearance on the downhill side, or a property with several retaining walls all take longer to inspect properly, because we still have to get in and look. Multi-level homes and those with monolithic cladding also take longer.
Ring us with the address, and we will give you a firm price for that property rather than a range.
Our inspector carries out a complete building inspection in accordance with NZS 4306:2005, the New Zealand Standard for residential property inspections. It looks at:
We test for moisture throughout, with particular attention to the windward faces of the building, where Wellington's driven rain is most likely to find a weakness. On a hillside property, the subfloor matters more than usual, because that is where you find out whether the piles, the retaining and the drainage are still doing their job.
You get a written building report in plain English within 24 to 48 hours, with photographs of anything we found, findings grouped by severity, practical advice on repairs and maintenance, and a verbal summary if you want one. If any terms in the report look unfamiliar, this guide to reading a builders report explains them.
Yes, that is the core of what we do. A pre-purchase building inspection gives you an independent account of the property's condition before you are committed, so you can negotiate, walk away, or buy with your eyes open.
In Wellington, the questions that decide a purchase are usually about weather, ground and seismic status rather than anything cosmetic. How exposed is the site, is the subfloor dry, how is the slope retained, and what is the building's earthquake rating? Those are the things we focus on here. Our property inspection checklist covers the wider picture of what a buyer should work through.
Wellington has a distinctive set of problems, driven by the city's wind, terrain, and seismic risk. The ones we see most often are:
Our guide to common building defects covers the most frequent defects in more detail.
This is one of the most important checks in Wellington, and one of the easiest, because the information is public.
A building is legally earthquake-prone when it is assessed as being below 34% of the new building standard (NBS). Exactly 34% is not earthquake-prone. Wellington is classified as a high seismic risk area under the national system, which is the same category as Christchurch, Napier, Palmerston North, Blenheim and Gisborne.
Three things to do:
Buildings rated from 0% to less than 20% NBS carry an orange and black notice. Those rated 20% to less than 34% carry a white-and-black notice. The risk of collapse in a moderate earthquake for an earthquake-prone building is roughly 10 to 25 times that of a building at 100% NBS.
Owners are given a deadline to strengthen or demolish, and in a high seismic risk area, that is 7.5 years for priority buildings and 15 years for others, running from the date of the notice. The Building (Earthquake-prone Building Deadlines and Other Matters) Amendment Act 2024 extended eligible deadlines by four years, so the date on the register may be later than an older notice on the wall. Check the register for the current deadline rather than relying on the notice.
It depends on the rating and what you intend to do with the building, but it can affect four things.
A building inspection cannot determine the rating. Seismic assessment is engineering work with its own methodology, and it is a separate report from ours. If the rating is unknown, that's worth resolving before you buy, not after. We will tell you what we can see, such as obvious structural issues or evidence of previous strengthening, and where an engineer's assessment is needed.
Not always, but hillside properties deserve more care here than almost anywhere else in New Zealand, and sometimes the answer is yes.
Wellington City is built on steep terrain over Torlesse greywacke, a rock with closely spaced fractures and uneven weathering. That geology, combined with the city's steep, dissected hills, makes the slopes prone to landslides, mostly triggered by rainfall rather than earthquakes. This is why slope stability is a genuine consideration on a Wellington hill rather than a theoretical one.
Things worth taking seriously when you look at a property:
A useful free check is the Natural Hazards Commission's portal, which records previous claims, and it is worth asking the neighbours and the council about the slope's history. Our foundation inspections page explains what we can and cannot determine from a visual inspection.
Where we see something that needs more than a visual assessment, we will say so and recommend a geotechnical engineer. A geotechnical report covers the geology, groundwater, drainage, slope stability and foundation design, and it is the only way to establish the actual risk.
Two legal points worth knowing. Retaining walls above a certain height, or those supporting a building, a boundary, or a surcharge load, may need building consent or resource consent and should be designed by an engineer. And under the Building Act, a new building or major alteration on land subject to a natural hazard such as slippage must not make that hazard worse, and the council can record the hazard on the title. That is a real flag to look for in the LIM.
Yes, and in Wellington this is central, not incidental. The combination of high rainfall, strong wind and homes built into hillsides makes moisture the most common serious problem we find.
We check subfloor ventilation and ground moisture; moisture levels in walls, ceilings, floors, and joinery; where water is getting in around windows, doors, and cladding penetrations; bathroom and shower waterproofing; and the roof space. We use both pin-type and non-invasive meters.
For properties from the leaky building era (roughly 1988 to 2004), we test more extensively and assess the risk profile based on the cladding type, design features, the site's wind exposure, and the maintenance history. Where our findings indicate a real concern, we will recommend a full invasive moisture investigation by a specialist weathertightness consultant. See monolithic cladding and weathertightness for how we assess it, and moisture testing for what the meters actually measure.
If you are buying a rental, our investment property building inspections page covers what else we look at, and where dampness cannot be resolved, a council can treat a building as insanitary, which our guide to a safe and sanitary report explains.
Wellington is measurably the windiest main centre in the country, and the numbers matter because they explain what happens to buildings here.
Stats NZ measures Wellington as having the highest annual average of the daily maximum wind gust in New Zealand at 65 km/h, well clear of the next site. Wellington's annual maximum gust averaged 134 km/h over the ten years to 2022. So a gust over 120 km/h is close to the strongest the city sees in a typical year, not a routine event, and it is a useful benchmark for what a building here has to withstand over its life.
For construction, most New Zealand houses are designed to NZS 3604, which puts Wellington in wind region W (the Cook Strait region) and grades sites from low to extra high. An extra high site is designed for a maximum ultimate limit state wind speed of 55 metres per second, and anything above that needs specific engineering design. Exposed ridgelines and hilltops can sit in the highest bands, and lee zones behind the hills can push a site up two whole steps. This is why two houses a few streets apart can have quite different bracing and fixing requirements.
What that means in an inspection: we pay close attention to roofing and its fixings, flashings and their laps and fixings, cladding junctions, and anywhere wind-driven rain can be pushed past a seal. Poorly detailed junctions that never leak somewhere sheltered can leak here. Where we find something, we will tell you whether it needs monitoring, repair, or a specialist report.
If the house was built or renovated before the mid-1980s, you should assume asbestos-containing materials may be present until proven otherwise.
Wellington has a large stock of pre-1980s housing, and asbestos was used widely through that period in places people do not expect: fibrous cement cladding and soffits, roof sheeting, vinyl floor tiles and their backing, textured ceilings, water cylinder and pipe lagging, and the adhesives and sealants around them.
If it's intact and undisturbed, it is usually not a problem. It becomes one the moment a renovation cuts, sands, drills or demolishes it. We identify materials that look suspect and will tell you where they are, but confirming asbestos requires laboratory testing and removing it requires a licensed removalist. Our guide to asbestos in New Zealand homes covers where to look and what to do.
It is common in a city with this much older housing, and on hillsides it carries more risk than usual, because unconsented work here often means a retaining wall, a deck, a sleepout or a basement excavation.
Those are exactly the works that interact with the slope. A retaining wall built without consent and without engineering may be holding up ground it was never designed for, and a cut into a hillside can change the drainage everything below it depends on. Sometimes the work is fine and simply was never documented. Sometimes it is not, and then it is a structural or stability problem as well as a legal one.
We note work that appears unconsented and flag it, but we cannot make a legal determination. You can check the consents on the property through Wellington City Council, and a LIM will list what has been consented. Buying unconsented work can mean the cost of remediation, getting a certificate of acceptance, or demolition landing on you. Our guide to unauthorised building work sets out the legal and financial risks.
Yes. A new build can have incomplete work, detailing defects, and items the builder intends to come back to, and it is far easier to get those put right before settlement than afterwards.
Wellington's environment is unforgiving, which cuts both ways. Shortcomings in construction are exposed sooner here, so problems show up quickly, but they also do damage faster once they start. Incomplete flashings, drainage that has been connected but not correctly bedded or graded, bathroom extraction ducted into the ceiling cavity rather than outside, and cladding junctions sealed rather than properly detailed are all things we find on homes that are only a few years old.
See our new construction inspections to see what we check on a new build.
Most take one to two hours, depending on the size, age and condition of the property. Allow longer for a hillside property, a multi-level home, a property with an extensive subfloor, or one with monolithic cladding, because those all need more detailed assessment.
Terrain is the main variable. A house cut into a slope over several levels, or one with limited subfloor clearance on the downhill side, takes longer because we still need to get in and look, and access is genuinely harder.
You are welcome to come along, and if you do, allow the full time. The report follows within 24 to 48 hours.
Absolutely, and we encourage it. You will see what we see, and you can ask questions on the spot about anything that concerns you.
It is particularly valuable on Wellington properties, where features like retaining walls, subfloor conditions, and wind-exposed elevations are much easier to understand when you are standing in front of them with the inspector than in a written description. There is no additional charge for attending.
Many of our clients are buying from outside the region and cannot get there. If that is you, we will talk you through the findings by phone, and you are welcome to ring us afterwards with anything the written report does not make clear. If you need the report against a deadline, see urgent building inspections.
Yes. Our inspectors are trade-qualified with experience in New Zealand residential construction, and every inspection follows the New Zealand Standard for residential property inspections, NZS 4306:2005. We hold professional indemnity insurance.
They also know this region. Wellington's problems are not the same as Auckland's or Christchurch's, and inspecting here means understanding wind zones and weathertightness, what hillside construction does to drainage and retaining, which housing eras carry the leaky building risk, and what a low earthquake rating actually means for a buyer. You can meet the inspectors on our team page, and take a look at the services we provide.
Our reports are written in plain English and supported by photographs, so that what we found and what it means are both clear. If you have a question about anything in your report, ring us, and we are happy to talk it through.
We cover the whole greater Wellington region: the CBD and the inner suburbs; over the hills to Karori, Brooklyn, Johnsonville and Tawa; along the coast through Porirua and the Kāpiti Coast; and up the Hutt Valley to Lower Hutt and Upper Hutt.
If you are not sure whether we reach a particular address, ring and ask. We would rather tell you straight than have you find out later.
If you are looking for a building inspector near you in Wellington, we cover the wider region, not just the central city, and we inspect across it all. Wherever the property is, you get a firm price before you book, based on the address.
Wellington's terrain is worth mentioning up front. A steep right of way, a house cut into a slope, or a subfloor with limited clearance all add inspection time, and we would rather tell you that when you book than surprise you afterwards. Book by ringing 0800 4 ALERT (425 378) or through our contact page, and we will confirm your inspection time.
If you want to read more before you book, our building inspection questions and answers page covers the things people ask us most.
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