Structural framing is an integral part of a building’s strength and resilience in an event such as an earthquake. There are various options available for structural materials however the suitability of certain materials will differ depending on factors including the site’s location, the type and size of the building, environmental issues, the type of soil and the sites itself. The type of structural framing specified will depend on a combination of some or all of these factors.

Cost effective framing materials

There are many ways to reduce the overall cost of a new build, and the type of framing material used is a significant one. Often, the cost effectiveness of structural framing materials can be increased by opting for prefabricated materials that are assembled off site and delivered ready to install. Prefabricating materials is a way to reduce waste and ensure time-effective manufacturing that is not impacted by weather or other environmental factors.

Structural framing requirements

A building’s geographic location may determine the type of structural system required, particularly if the site is located in an earthquake zone or may be exposed to high winds or snow loads. Buildings in high earthquake zones for example generally require specialised structural systems that differ from those required in other areas. There are detailed requirements in place for all structural systems and load-bearing elements such as trusses that require different solutions depending on the individual project.

Using a structural system aesthetically

Depending on the preference of designer and owner, a structural framing system can be incorporated as an architectural feature. Using structural systems in this way is particularly popular in buildings where an industrial aesthetic is the preferred option. Often, exposed framing can contribute to a dynamic interior space.

Concrete

Concrete has been used in construction for more than a thousand years in different forms. It is one of the most durable construction materials and is often used for load-bearing walls. However, in structural applications, concrete may require steel reinforcing, particularly in seismic zones. Concrete slab floors are also commonly used, and it is a sought after flooring material in passive houses as it acts as a thermal heat sink, helping to moderate an internal ambient temperature.

Steel frame construction

Steel is often used as a framing material because of its durability, strength and price point. Steel frames are comparatively easy to handle and most are prefabricated and delivered to site ready to assemble. There are two main types of steel frame construction: heavy and light steel frame construction. Heavy steel construction incorporates a structural skeleton of large steel posts and beams. It is often used in combination with other types of structural systems. Light steel construction on the other hand, can be used as a complete system - covering walls and roof framing - or for interior structural framing sections only.

Timber framing

Timber framing is the most common type of residential construction system in New Zealand, utilising post and beam, timber framing or solid timber construction. Timber construction is used in all climatic conditions in New Zealand but if it is exposed it requires treatment to ensure it retains its integrity. Exposed timber also requires regular maintenance to prevent degradation over time.

Timber is also commonly used in the form of timber pole foundations - a solution particularly popular for sites where houses need to be supported on poles due to a site being hilly, sloping or as a way to ensure minimal disturbance to the existing vegetation or ground.

Timber piles

Timber piles can also be used to support the floor of a structure. Generally, piles are used where the site is either level or gently sloping. Timber piles need to be treated to ensure they will withstand rot and other factors that could cause degradation over time.

Stone

Stone is not commonly used as structural material in New Zealand and is more often than not used for facades, internally as a decorative element and to create exterior features such as non-structural columns or on panels of a facade or wall.