Problems and conflicts involving protection works can be avoided if appropriate procedures are followed, works carried out and suitably confirmed. Applicants and respondents would benefit from guidance as to appropriate technical scope of protection works. Such guidance is not yet readily available in the industry.
The recent dramatic collapse of a building in inner Melbourne has highlighted concerns over protection works. While collapses from adjacent construction activity are uncommon, issues related to protection works may cause damage and escalate into unnecessary disputes.
The term "protection works" in the context of the Building Act means works required to protect one property from construction activity on an adjoining property.
Protection works are not merely the building works but include construction method, materials handling, temporary, and in some cases permanent support systems. Protection of the property, not merely the building is required, so works often include control and protection of excavations.
The Building Act invokes protection works at the discretion of the RBS when there is a risk of "significant damage" to an adjoining property. Significant damage is not defined but a common example of damage that may be accepted without protection works is minor ground breakout into a footing trench for domestic scale construction. "Adjoining" properties include any nearby, not merely those immediately adjacent.
Commonly construction on the boundary is a trigger for the requirement for protection works and a distance of 1m from the boundary is another rough guide but consideration should always be given to the nature of the works and structural issues. Larger scale construction, such as deep excavation can extend the requirement for protection works for a considerable distance.
The Building Act includes provisions for protection works the practical purpose of which is define, control, document and insure such works. Many BDPS readers will be familiar with the procedure that commences with exchange of form 3 and 4 documentation between the "Owner" (applicant) and "Adjoining Owner" (affected party) in an attempt to agree the scope of protection works.
If scope cannot be agreed between these parties it is resolved by the RBS or Building Appeals Board. The act contains detailed requirements and the Building Commission has a number of practice notes available. There are also requirements under the act for the owner to provide insurance of the protection works (this is beyond the scope of normal construction insurance). A dilapidation report must be carried out of the adjoining properly and agreed by both parties. Inspections of the protection works on behalf of the adjoining owner are allowed for under the act and there is a requirement for the owner to provide as built documentation of completed protection works to the adjoining owner.
If all the above is followed disputation and adverse events during construction are unlikely. This is a supremely sensible process prior to carrying out works that may affect another and to the benefit of both parties. Unfortunately matters do not always run as smoothly as they should, there are common themes to most of the conflicts that I see. A typical scenario is as follows:
- The RBS deems that protection works are required and requires the applicant to serve protection works notices upon the adjoining owner.
- The applicant has no idea what "protection works" are and little interest, he just wants his permit, so he fills in the statutory forms and serves them on the adjoining owner, the forms contain no technical content beyond cross reference to the building permit drawings at best.
- The adjoining owner seeks advice. When assessed the "protection works" proposed are inadequate and the process of negotiating suitable protection works from the applicant begins. This is a long and agonising process involving several parties and experts and delays the permit further. The applicant is required to pay the reasonable fees of the respondent's expert. The RBS and in some cases BAB are involved to resolve matters that could have been resolved with appropriate initial input.
- The process has proven expensive and protracted and we have only got to the stage of defining the works.
- Inspection and confirmation and provision of as built documentation is neglected as there is no statutory process to formally close works as for a building permit.
Many applicants would benefit from some knowledge of what "protection works" are and should be: It is important to understand that they extend beyond the mere building specification to the process and method of construction and issues related to the construction activity. The definition is broad but here are some common issues:
- Physical protection from extraneous matter, beside and above the built works. For example, protection from falling debris. This can be usually achieved by screening, hoarding or covering. Dust reduction is often best tackled by reduction at source by wetting.
- Protection of excavations and undermining of footings. A common scenario of an excavation that may influence an adjoining footing is best dealt with by altering the design to obviate the undermining. Failing that staged construction so that only acceptably small portions of undermining occur is an alternative. Another is lateral support of the excavation by shoring. The last resort is underpinning of the adjacent footing. In general carrying out direct works to adjoining properties is best avoided. Appropriate structural engineering and geotechnical advice should always be sought.
- Protection from geotechnical changes such as foundation problems from the lowering of a water table. Increased intensity of urban development and he proliferation of basement car parks have made this a common scenario in recent years. If a building is based on a reactive clay foundation and the new basement adjacent is drained the water table is likely to be lowered over an area adjacent the basement. If this dries out the clay foundation shrinkage of the foundation and settlement of the adjacent building are almost inevitable. This is a particularly difficult issue to resolve. In the first instance one looks for a geotechnical opinion as to whether it is a problem and if so how big. If movement is likely the options reduce to accepting and repairing damage or underpinning.
- Protection from noise, vibration or other indirect construction activities. These are usually controlled by construction procedures that are difficult to enforce.
- Reinstatement of associated works, such as fencing.
- Making good finishes on newly constructed or altered surfaces exposed to the respondent's site.
While strictly protection works are only required to avoid "significant damage" when I am recommending protection works I usually extend this to any damage that can reasonably be controlled and any housekeeping or courtesy items, such as finishes of walls. Such matters cost little, make agreement more likely and smooth the wheels of neighbourly relations.
Standard practical guidance suggesting technical content of protection works is not readily available and would be of value to the industry. It would not be difficult to produce a guide covering common protection works. It would not be realistic to make such guidance comprehensive as there will always be issues requiring specific engineering and geotechnical input.