This page provides general advice about building green roofs, walls and facades, including
- occupational health and safety
- insurance considerations
- what to expect at project completion on a large-scale job which has a project manager and several consultants.
Occupational Health and Safety (OH&S)
As for all construction work, the construction (and maintenance) of green roofs, walls and facades is subject to the Victorian Occupational Health and Safety Act 2004. This Act governs all Victorian OH&S laws and codes of practice and sets out the key principles, duties and rights in relation to OH&S.
Guidance materials available from WorkSafe Victoria inform duty holders on how to comply with Victorian OH&S legislation. Consultants can also provide advice on ensuring OH&S requirements are met.
Note that National Workplace Health and Safety codes and guidance materials have no legal status in Victoria.
High-risk construction work
Some construction projects involve high-risk construction work and additional regulations govern management and procedures in such cases. High-risk construction work is of particular relevance to the design, construction and installation of green roofs, walls and facades as it is likely to involve work:
- where there is a risk of a person falling more than two metres
- on or near electrical installations or services, for example, the possibility of drilling into a wall containing live electrical wiring
- at a workplace where there is any movement of powered mobile plant, for example, working in an area of a construction site with moving skid steer loaders, telehandlers, backhoes, mobile cranes or trucks
Materials handling and storage
As on any building site, the materials used to construct a green roof, wall or facade should be delivered in a timely way to meet construction schedules. Consideration must be given to where materials will be unloaded and stored and how they will be moved to and from site. Secure storage and safe handling of materials on-site may be needed. For safety reasons, a roof must not be used for materials storage when a green roof is being constructed, as it is a building site and must be managed for weight, access, security of materials and safe movement of personnel.
Working at heights
The design and installation of all green roofs – and many green walls and facades – involves work at heights. The associated risks and responsibilities must be managed through a combination of training and safety features on the site including the use of barricades, railings, or other fall arrest systems, such as ropes and harnesses.
Consult the WorkSafe Victoria Compliance Code ‘Preventing Falls in General Construction’ with regard to specific OH&S issues associated with working at heights and management solutions. Wherever possible, the risks and hazards of working at heights should be removed or reduced and the design team must consider these as part of project planning.
Safety in design legislation
A Safety in Design risk assessment or workshop should be undertaken with the design and construction team/s to identify risks and determine the actions necessary to remove or reduce the likelihood of occurrence and severity of these risks.
Insurance and system warranties
The scale, complexity and overall cost of a green roof, wall or facade will determine whether insurance and warranties are relevant. Almost all professionally-installed projects will include them; smaller, DIY projects may not.
Until the local industry is further developed, it may be beneficial to consider insurance companies with a global reach that gives them relevant understanding and experience. Commercial insurer FM Global provides useful specifications for green roof design, installation and maintenance that can be used as a risk management tool during design and planning.
The warranty for a green roof, wall or facade will be straightforward if an established installation company, or a contractor licensed by that company, installs a proprietary system. Under these circumstances, the parent company should provide a warranty against failure of any or all of the components. Custom-built green roofs, walls or facades, with mix-and-match components, or multiple providers, may not be as straightforward to warrant or insure.
Waterproofing is more likely to be warranted separately if it is installed by a third party. However, the company supplying and/or installing the waterproofing may not take responsibility for breaches of the membrane that occur after it is certified as watertight, if they have no ongoing involvement with the project. Ensure there is clarity around the warranty conditions.
The client usually has the option to negotiate a defects liability period with the contractor. The contractor will be responsible for repair of defects that appear within an agreed period of time after project completion and may have responsibility for defective work beyond the product warranty period. Warranties may be waived if a DIY approach is undertaken with the product.
Contractors and sub-contractors must provide necessary certifications at the completion of their work. At handover, the project manager will provide documentation of all necessary inspections and relevant certifications to the building owner. These should include:
- warranty on waterproofing
- drawing showing ‘as built’ planting (the actual planting may have varied from the design drawings)
- certificate of completion from a registered building inspector
- certificate of electrical safety from a licensed electrician (if relevant)
- certificate of occupancy (if relevant) from a building inspector/local council – this will relate mainly to safety and access requirements, including step heights and access points
Operational manuals must be handed over to the owners and/or contractors who will be engaged in operation or maintenance of the site. This must include the setting of an agreed time for any initial or ongoing training in the operation of systems installed on the site. Provision of funds for such training should be included as a contingency item in the budget during the design phase.
Maintenance or operational manuals may include:
- a planting maintenance plan
- an irrigation operations manual
- schedules for cyclical maintenance
Maintenance is discussed in more detail here.