Operational Phase

We provide the following services during the operational phase:

Forensic Investigations

Our building surveyors provide expert advice on how building enclosures perform. Building surveyors have a comprehensive knowledge of building enclosures. They understand the complex interaction of materials, building code requirements, legislation, design and environment. Surveyors at Alexander & Co. assist clients by identifying and developing solutions to building failure, preparing conceptual and technical solutions, and managing the design and delivery of construction projects.

Our surveying process begins with a thorough investigation. Weather-tightness issues can be caused by any number of things, from faulty workmanship to poor quality or incorrect materials. In order to resolve a building’s issues, we must first diagnose the causes. Our various levels of investigation are tailored to a building’s unique situation to help minimise the disruption and costs. Depending on your property, specialised investigation might also be recommended, such as façade testing, hygrothermic data collection or testing samples in an independent lab. 

Following investigation, our architects and design team work together designing the changes to be made to your property so that it is both aesthetically pleasing and resolves your weathertightness issues for the long run. We then support you through the process of implementing these changes. We use our expertise to minimise disruption during construction and manage things such as planning applications, monitoring and sub contractors.

Building surveying services we provide:

  • Forensic investigation of building failure
  • Leaking building investigations
  • Indoor moisture investigations
  • Assessment of buildability, sustainability and maintainability
  • Energy efficiency auditing and modelling
  • Obtaining building consents
  • Tendering, negotiation and contract establishment with contractors
  • Building monitoring services
  • Engineer to contract
  • Monitoring of compliance and quality
  • Client representative / quality review
  • Maintenance surveys
  • Maintenance planning and management

For expert building surveying services contact us today to discuss your project.

Condition Surveys and Maintenance Planning

 The objectives of our condition survey and maintenance planning service are as follows:

  • To determine the current condition of the building enclosure components and services.
  • To determine the remaining life of components i.e. roof cladding, wall cladding, joinery, plumbing and water, electrical, heating/ventilation & mechanical systems.

The output from the surveys include:

1. Risk Profiling Sheet.

2. 10-year maintenance schedule with costs.  The 10-year maintenance schedule will identify the activities required to routinely maintain the asset as a whole. The resulting maintenance schedules are priced by a quantity surveyor.

3. A report detailing the findings of the condition survey.  The report will detail the current condition of the building enclosure, a summary of defects, maintenance requirements and health and safety issues. 

Please find the case study 1 related to condition surveys by clicking here or going to Case Studies page.

Building Performance Monitoring

Hygrothermal Testing

Comprehensive investigations, while extremely useful to identify issues with a building and its components, only provide a snap shot of the building at the time of inspection. Learning how a building functions on a daily basis; its wetting and drying cycles allow us to gain insight into the quality of construction and to more accurately pinpoint current or potential problems. That is where hygrothermal monitoring comes in. Hygrothermal monitoring is essentially the collection of moisture and temperature conditions within the building assemblies over a given amount of time (this could range anywhere from one month to one year).

Sensors embedded within the assemblies take regular measurements of the relative humidity and temperature within the cavity, pressure differences across the cladding and the moisture content of timber components. This data is then transmitted to our computers in the office where we can format and analyse the information – looking for patterns to better understand how the building is performing on a day-to-day basis.

The type and number of sensors used on a project is tailored to suit the goals and scope of that project. However, we try to incorporate a good range of sensors in several locations around the structure to obtain an overall perspective of the building’s performance.

Below are examples of units that have been installed in a current project.


An overall view of a typical cutout for sensor installation. Moisture and relative humdity sensors have been installed in the cavity before the cutout is sealed and patched over.

An overall view of a typical cutout for sensor installation. Moisture and relative humdity sensors have been installed in the cavity before the cutout is sealed and patched over.

A sensor configuration installed within a wall cavity. Moisture sensors have been installed at the base of the stud as well as the back of the cladding, with a temperature sensor taped to the building paper.

A sensor configuration installed within a wall cavity. Moisture sensors have been installed at the base of the stud as well as the back of the cladding, with a temperature sensor taped to the building paper.

A temperature/relative humidity graph from the collected data. Raw data from the data acquisition units was exported into Excel where it was formatted and plotted for easy interpretation.

A temperature/relative humidity graph from the collected data. Raw data from the data acquisition units was exported into Excel where it was formatted and plotted for easy interpretation.


Testing Services

We provide the following testing services:

  • Facade Testing
  • Airtightness Testing
  • Air Quality Testing

Facade Testing

Using a calibrated spray rack we can simulate heavy weather conditions to test the performance of external cladding and windows. The interior is depressurised and a measured amount of water is delivered to the exterior wall. This process allows us to accurately identify where leaks lie and where water runs.

Airtightness Testing

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Air Quality Testing

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Design Phase

Our architects and building surveyors work hand-in-hand to ensure you get a property that looks great, and will remain watertight into the future. Remedial design takes into account all the elements that need to be replaced, repaired or amended to remedy the issues and prevent them from recurring. This means Remedial Design is far more complex than designing a new building. 

The process

The design process is most efficient when it’s split into two phases. The first is "Concept Design", which is where we outline the changes that need to be made to the property. This detail also allows us to produce more accurate costs. Concept designs are often just a written description, as in cases where a simple re-clad of the building will fix the problem. More complex projects can require drawings. 

The second phase, "Detailed Design", is where we sort out all the necessary details for remedial work to begin. The steps that need to be taken vary from project to project, but often involve producing more detailed drawings, seeking building consents and consulting with experts. Remedial design – for a building that looks good and remains watertight in years to come: contact us today to discuss your project.  

What we can provide for you

Typical services and stages might include:

  • Site assessment and feasilibity studies

  • Conceptual design

  • Developed design

  • Detailed design

  • Resource consent documentation

  • Building consent documentation

  • Working drawings

  • Independent design reviews

  • Performance modelling 

  • Quantity Surveying Services


Residential Design

We offer residential design services, including private houses and multi-unit dwellings. Our architects have a wide range of experience in the residential sector and have won NZIA awards for their projects. Our experience in remedial works means we are highly competent in designing buildings that not only meet the requirements of the brief, but do so in a way that is designed to last a long time.

Commercial Projects

We currently have a number of remedial projects with values ranging from $3 million to $15 million, so are dealing with large projects on a daily basis. Our staff is experienced in new build commercial projects and have worked on office buildings, recreation facilities, mixed use developments, office fit-outs, hospitals, community and institutional buildings and industrial buildings.

Cladding Design

Cladding design involves the appraisal of architecture, aesthetics and science of materials to form a weathertight building enclosure. We regularly provide design reviews of building enclosures for architects. Internationally, architects recognise the value in obtaining specialist advice regarding building enclosures.

Enclosure Design

Our experience with building science and remediation processes provides you with enclosure design that exceeds expectations.

Independent Building Enclosure Design Review

The purpose of the review is to evaluate whether the enclosure of the building, if built in accordance with the plans and specification, would satisfy the performance requirements of the building code. The building enclosure is the parts of a building, above or belowground, that physically separate the exterior environment from the interior environment.

Our design review service is offered in three stages. The three reviews are held at the following stages of the design process:

·       Stage 1:  To be undertaken on completion of the concept design

·       Stage 2:  To be undertaken 30% through the detailed design

·       Stage 3:  To be undertaken on completion of the detailed design

Stage 1: Risk reduction

A review of the concept design to identify the areas of design risk that need to be mitigated. The output from this phase is a commentary regarding the proposed design and materials selection.

Stage 2: Identify, evaluate and recommend

This stage involves a review of documents to identify features or details that need further design consideration.  A written list of issues is provided with recommendations for improvement or a letter confirming that the design is satisfactory.

Stage 3: Check

Checking the changes made in response to the items raised within Stage 2. This will include collaboration with parties to provide design assistance regarding direction on how features or details need to be changed.

Providing a letter stating that the design review has been conducted and the building enclosure would, if built in accordance with the reviewed plans and specification, satisfy the performance requirements section E2 of the building code. 

Performance modelling

We offer a range of computer modelling services that predict the performance of your building during the design phase. This analysis determines that the design satisfies the requirements specification and supports design trade-off decisions. The modelling available includes:

  • WUFI
  • Energy Efficiency (THERM)
  • HomeStar Assessments
  • GreenStar Assessments 


WUFI® (Wärme und Feuchte instationär) is a software family which allows realistic calculation of the transient coupled one and two dimensional heat and moisture transport in multi-layer building components exposed to natural weather. It is based on the newest findings regarding vapour diffusion and liquid transport in building materials and has been validated by detailed comparison with measurements obtained in the laboratory and on IBP's outdoor testing field.

WUFI can be used for assessing:

  • the drying time of masonry with trapped construction moisture
  • the danger of interstitial condensation
  • the influence of driving rain on exterior building components
  • the effect of repair and retrofit measures the hygrothermal performance of roof and wall assemblies under unanticipated use or in different climate zones.

WUFI is a tool for developing and optimising building materials and components. WUFI is directed at manufacturers of building products, consultants, designers, engineering offices and experts in the field of hygrothermics.


Building physics is one of the keys to a successful building project. The Fraunhofer Institute for Building Physics IBP focuses its work on research, development, testing, demonstration and consulting in the various fields of building physics. These include noise control and sound insulation in buildings, the optimisation of auditoria acoustics and solutions for improving energy efficiency and optimising lighting technology. Fraunhofer IBP’s work also covers issues of climate control and the indoor environment, hygiene and health protection, building material emissions, weatherproofing and protection against heat and moisture, preservation of building structures and the conservation of historic monuments. 

PC-Program for calculating the coupled heat and moisture transfer in building components

Realistic calculation of the transient hygrothermal behaviour of multi-layer building components exposed to natural climate conditions.

The menu-driven PC program WUFI (Wärme und Feuchte instationär - Transient Heat and Moisture), developed by IBP and validated using data derived from outdoor and laboratory tests, allows realistic calculation of the transient hygrothermal behaviour of multi-layer building components exposed to natural climate conditions. WUFI is based on the newest findings regarding vapour diffusion and liquid transport in building materials. WUFI only requires standard material properties and easy-to-determine moisture storage and liquid transport functions. WUFI can use measured weather data - including driving rain and solar radiation - as boundary conditions, thus allowing realistic investigations on the behaviour of the component under exposure to natural weathe

Below is a screen shot of the system.

Energy Efficiency (THERM)  

Two-Dimensional Building Heat-Transfer Modelling

THERM is a state-of-the-art computer program developed at Lawrence Berkeley National Laboratory (LBNL) for use by building component manufacturers, engineers, educators, students, architects, and others interested in heat transfer. Using THERM, you can model two-dimensional heat-transfer effects in building components such as windows, walls, foundations, roofs, and doors; appliances; and other products where thermal bridges are of concern. THERM's heat-transfer analysis allows you to evaluate a product’s energy efficiency and local temperature patterns, which may relate directly to problems with condensation, moisture damage, and structural integrity.

THERM’s two-dimensional conduction heat-transfer analysis is based on the finite-element method, which can model the complicated geometries of building products.

HomeStar assessment 

HomeStar is an independent rating tool that certifies the health, efficiency and sustainability of New Zealand homes. 

A home is rated on a 1-10 scale: a rating of 1 Homestar means it needs significant work, and 10 Homestar indicates international best practice. Most existing New Zealand homes only achieve a 2-3 Homestar rating. A new home built only to Building Code would achieve 3-4 Homestar.

At 5 Homestar, you have a home that’s better than Building Code; but 6 Homestar is the level at which you’ll start to notice a real difference in terms of better warmth, dryness, health and water efficiency. That’s because it’s certified as having:

  • better levels of insulation than Building Code requires, so your home is cheaper to heat
  • moisture-control measures
  • water-efficiency measures such as dual flush toilets and low-flow showers, to save you money on water and/or hot-water bills.

There’s no one way to achieve a Homestar rating – although houses have to score a mandatory minimum number of points in energy, health and comfort, there are many options in other areas. For example, some people might opt for photo-voltaic panels for solar energy; others may want to score high for good waste practice.

GreenStar assessment 

Greenstar is a commitment to standards of best practice and leadership for the development of environmental tools for buildings in New Zealand. These include:

  • A common language and standard of measurement
  • Promotion of integrated whole-building design
  • Awareness of green building design
  • Recognition of environmental leadership
  • And reduction of environmental impact of development

Our Quantity Surveying team has the extensive industry experience, capability and resources to provide a full range of quantity surveying services. We are able to draw on current and historic industry information, together with our costing database of projects, to provide accurate estimating and costing information. 

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Quantity Surveying services we provide:

  • Condition survey costing, life cycle costing & long term maintenance planning
  • Construction cost advice & estimates to make decisions on project viability
  • Option appraisal to ensure the most cost effective solutions are carried out
  • Tender analysis & reporting
  • Financial management assistance during the construction phase including reporting on cash flow & cost to complete
  • Assessment & negotiation of variations
  • Assessment & negotiation of progress claims, & the issue of payment schedules in conjunction with the Engineer to the Contract
  • Preparation & negotiation of final accounts
  • Apportionment of costs for multiple stakeholders
  • Quantum estimation for dispute resolution and weathertightness claims, including attending mediation or Court hearings and acting as an expert witness
  • Replacement insurance valuations for existing buildings
  • Advice on Building Code Compliance
  • Advice on maintenance and durability issues

For expert quantity surveying services contact us today to discuss your project.




Procurement and Tendering Phase

  • Tendering and appointment of contractor

  • Contract administration





Construction Phase

We provide the following services during the construction phase:

Construction Monitoring / Observation

Our construction monitoring service provides supplementary quality observation to ensure the following:

  • That the work is completed in accordance with the contract documents including all drawings and specifications and the manufacturers’ technical literature for the products and materials installed.
  • Good trade practice.
  • Compliance with the Contractor’s Quality Plan.
  • Compliance with the Building Consent.
  • Compliance with the NZ Building Code.


Engineer to the Contract




Dispute Resolution Services

If you suspect your property’s weathertightness issue has been caused by faulty building practices or incorrect building materials, you may wish to seek compensation from the Weathertight Homes Tribunal, or from the "at-fault" party. 

If you are entering into legal disputes proceedings over your property’s weathertightness issues, our expert surveyors can help. The evidence we collect while monitoring the remedial work of your property is accurate enough to be used in legal proceedings. 

We also provide a service in supporting legal teams by acting in an expert witness role, using accurate and reliable information collected by our investigation team. This equips your legal team to make the most compelling case on your behalf to help you reach a fair settlement.  

Dispute resolution services we provide:

  • Expert witness
  • Disciplinary reviews and investigations
  • Adjudication of disputes under Construction Contracts Act 2002
  • Determinations

Need support for your legal proceedings? Contact us for expert advice from our experienced surveyors.




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Under Construction