1 General information collection stage

The collection of general information about the building early in the remediation process will help consultants direct attention to areas that are most at risk of leaking.

Some information should be available from the BCA records, while further knowledge can be gathered by exploring the neighbourhood. A 'street-side' perusal with photographs taken is useful for assessing general features of the building and site. Information should be sought on the age and history of the building (including the building materials used, timber type and degree of any timber treatment), component installation dates, leak history, details of past maintenance and any previous repairs.

1.1 The property

When consultants inspect a property, they should pay attention to those particular characteristics that are likely to influence the building's weathertightness and durability.

Further detail
Figure 3, Table 5, Appendix 3: Checklist for information collection

1.1.1 The building

• Type of building - detached house, multi-unit complex, other type
• Foundations - concrete, timber, subfloors, retaining walls etc
• Walls - cladding materials, framing type,timber treatment, fire ratings, bracing etc
• Windows and doors - materials, installation, special types (such as box/corner windows, raked /curved tops, fire ratings)
• Decks - numbers, types, floors, balustrades, fixings etc
• Roof - material, slope, levels, design features
• Other features - parapets, clad columns/beams, framed 'chimneys', decorative bands, cornices, plinths, pergolas etc

The 'E2/AS1 risk matrix' can be used to assess general risks applying to each elevation and whether a similar design would now require a drained cavity to comply with E2/AS1.

Further detail
External Moisture - A guide to using the risk matrix

1.1.2 The site

• Location
  Salt-laden air affects the durability and maintenance needs of elements such as metal components.
  
  Very cold locations can also present special conditions for a building to cope with (such as movement resulting from extreme temperature changes and the ability to withstand moisture resulting from snow melting).
  
• Wind zone
  The wind zone may be moderated or increased by local factors such as site slope, trees and buildings (refer to NZS 3604 section 5.2 for guidance).
  
• Prevailing wind and rain
  Wind-blown rain will affect parts of buildings differently depending on local shelter, prevailing weather patterns and the terrain (hills create localised wind conditions).
  
• Slope
  The slope of the site affects surface water drainage and exposure, depending on the prevailing wind and rain.
  
• Orientation
  Sunshine and wind can promote the drying of claddings. However, sunshine also contains ultraviolet light, which can prematurely degrade some claddings, components, sealants and paints.

1.1.3 The current weather

Weather and seasonal effects

A prolonged dry spell combined with a type of construction that aids drying can often mean that there is little or no evidence of high moisture levels from the readings taken with a standard resistance type deep-probe moisture meter.

Moisture levels can also change significantly with the season, and can often be much lower in areas of advanced decay.

The season and weather can affect moisture testing results. These influential factors must be recorded and planned for.

The weather patterns over the 3 to 4 weeks before the inspection should be established. Allowance should be made for possible seasonal effects, and the time period for a survey may need to be extended to allow testing during seasonal wet weather or particular wind directions.

1.2 Construction history

A building's construction history can provide consultants with a basis for considering the results from diagnosis investigations and to then assess repair options during design.

Consent documentation
Where possible, copies of drawings, specifications and any approved amendments to the building consent should be obtained.

Details and specifications relating to cladding and timber framing and any information about designers, engineers and builders may be useful. Resource consent records should be checked for any conditions relevant to the remediation diagnosis and design.

Age of construction

Accuracy of records

While consent documents show original design intentions, supporting evidence is also needed because the final details and materials may have varied significantly from those shown in the original drawings and specifications.

A copy of the building consent and any code compliance certificate should be obtained. Copies of inspection records and reports should be sought (including any indicating the designer's role during construction).

An assessment should be made on when the building was occupied (as distinct from 'completed' according to the code compliance certificate), as this indicates the age of components in the building envelope and also the likely construction techniques common at the time.

Timber treatment
Evidence of the level and type of any timber treatment should be noted, as this is critical for informing later decisions on likely moisture damage and remedial options. As the specification alone is not sufficient, other supporting evidence (such as letters, statements, invoices etc) should be sought. However, it must be remembered that the only reliable evidence comes from removing timber samples and having these laboratory-tested for treatment types and levels.

Further detail
Refer A 2.3: Laboratory analysis

Producer statements and other information

The age of the cladding

The age of cladding is important for assessing its current condition. The cladding completion date can be significantly earlier than the building's completion.

The completion date should also indicate the manufacturer's technical details that should have been used at the date of installation.

Copies of any technical information, producer statements and warranties should be sought, particularly the manufacturer's information about the external claddings and coatings used on the building.

These records should help to identify the materials that should have been used (which may differ from those specified in the consent documents or from those actually used). They may also show the completion date of those parts of the work and the age of the elements (eg, the wall cladding).

Past repair work
Evidence of any past repair work should also be sought. If consented work was undertaken, the date, location and details available on the repair work carried out should be noted.

1.3 The owner or client

Understanding the owner or client's situation provides the consultant with a context for assessing remedial options during the design stage. Some general information can be collected prior to initial meetings with the client (saving time and informing discussions).

Nature of ownership
Clarification of the ownership and areas of responsibility for managing maintenance is important. This can affect later decisions and the time needed for client decisions and approvals.If the building is a detached house, is the client the occupier, or is the house tenanted? If the buildingis a multi-unit complex, is the client a Body Corporate or an individual owner of one of theunits? (Refer to 'Complexities of ownership').

Reason for seeking advice
Is the building currently leaking, or is the owner concerned about the possibility of hidden or future leaks?

Beware the 'quick fix'

Beware pressure for a 'quick fix' from an owner planning to sell. A consultant should not be party to substandard repairs. A sale could later be challenged if these repairs prove ineffective in preventing leaks and damage results. Recommendations must be based on results of the investigation, not just on an owner's short-term wishes.

Occupants
Gather any available information from occupants about the building and its problems (refer to 'Gathering further information').

Complexities of ownership

In a multi-unit complex, confirming ownership of common property is critical to the owners' decision-making processes - and to the apportionment of costs to various owners.

If the client is one of multiple unit owners, this introduces complications when repairing party walls. Body Corporate rules and restrictions must also be clearly understood.

Similarly, cross-leased properties can mean there are restrictions over individual properties (depending on the terms of the leases), which must be investigated and provisioned for.

Underlying motivation

If an owner intends to sell the property in the short-term (and wants a code compliance certificate), they may be aiming to spend as little as possible. The consultant must be prepared to explain their obligation to comply with the Building Code.

Building Code requirements are a minimum. If intending to keep the property longer term, an owner may want to meet higher standards - to reduce future maintenance requirements, to provide 'future insurance' and peaceof mind, or to improve the image of the building for future resale value.

1.4 Other information

Property value
A building's value can affect decisions as to the type, extent and even the viability of remediation work. Information on building values may be useful when considering remedial design options.

In an extreme situation, the repair of a badly damaged building may prove not to be economically viable if the costs of repair outweigh the replacement cost.

Gathering further information
Information from occupants
Outline some standard questions, such as:

- Can you show me any indication of water damage and other weathertightness concerns you have about the house?
- Has any repair work been done?
- Do you have any builder's, supplier's and/or manufacturer's warranties?

(And ask for any further relevant information.)

Other associated people
Also try to identify people/companies involved with the design, approval and construction and any previous remediation of the building (and seek contact details if available).

Sales history
The sales history of the property may also provide information. Sales histories that cover the past decade or more are commonly available for detached houses or units. Frequent sales of the property could indicate ongoing problems that need investigation.

Other reports
If past sales have occurred, these may have involved pre-purchase inspection reports. Other types of building assessments may also have been carried out (such as for a determination). Copies should be sought, as important information may be revealed that could inform the remediation process. However, historic reports should always be treated with caution and do not eliminate the need for further assessments.

1.5 Information within the remediation process

While initial information collection is described as a stage in the remediation process, it is not an activity that can be separated from the overall remediation process. As a project progresses through subsequent stages, further detailed information must be collected to confirm, adjust and add to the consultant's knowledge.

The initial collection of general information is actually the beginning of the diagnosis stage,which is explored in the following section.

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