Property 101: Dousing fire fears for mid-rise timber apartments

GUEST OBSERVER

 

The Great Fire of London in 1666 destroyed a third of the city leaving more than 100,000 people homeless – and prompted King Charles II to issue a proclamation limiting future construction largely to brick and stone.

 

For hundreds of years, modern building codes around the world reinforced the king’s approach, severely limiting the use of timber, particularly in multi-storey buildings, due to fear of fire.

 

However, in recent years, there has been a resurgence of mid-rise timber buildings in Europe and North America. In the Canadian state of British Columbia, for example, a change to the building code in 2009 allowing for taller timber buildings has seen more than 330 building projects earmarked for construction in timber – and more than 80 projects completed or under construction.

 

The resurgence has been enabled by a combination of growing awareness around the environmental and cost advantages of timber, and a willingness on the part of authorities to re-think the rules in the light of contemporary technology.

 

At the time of the Great Fire, London did not have a fire brigade. Londoners, assisted by soldiers, had to fight the fire with buckets and fire hooks– and the most effective way to stop the spread of fire was to demolish houses and create a fire break.

 

Today, not only do we have fire brigades, we also have automatic sprinkler systems, hose reels, portable fire extinguishers, smoke alarms, fire-protective grade plasterboard and cavity barriers, intumescent seals (door seals that expand in the event of fire to block smoke and hot gases)…

 

This year, the Building Code of Australia 2016 will include a Deemed-to-Satisfy (DTS) approach for timber buildings of up to 25 metres in effective height – typically eight storeys – on the proviso that a raft of safety features such as those I’ve discussed are included. Mid-rise buildings constructed in fire-protected timber – combined with sprinkler systems – can provide fire safety standards that not only equal conventional alternatives, but exceed them.

 

Modelling by EFT Consulting ahead of the code change suggests there would 83 per cent fewer fatalities and almost 70 per cent less property damage from fires in timber buildings conforming to the new DTS provisions, compared to conventional buildings – where no sprinklers are required.

 

The new provisions require: timber walls be ‘sandwiched’ between layers of fire-protective grade plasterboard of the type used in high rise commercial buildings; fire hydrants, hose reels and portable fire extinguishers similar to those for conventional buildings; fire-resisting cavity barriers e.g. mineral wool; and a fire sprinkler system.

 

The changes were approved by the Australian Building Codes Board technical committee that includes Engineers Australia, Australasian Fire and Emergency Service Authorities Council (state fire brigades), the Australian Institute of Architects, Master Builders Australia and the Housing Industry Association.

 

Just as fear of fires can be easily addressed when you look at the facts, reassurance can also be offered on other genuinely-held concerns – and enable the property domestic building industry to achieve the cost savings associated with timber, which is estimated by AECOM at 10-20 per cent in an Australian setting, largely because of faster build times.

 

Mid-rise timber buildings can be built on top of concrete ground floors, which, when combined with standard termite prevention measures such as barriers, traps and treatments, is sufficient to protect them; the designer of any mid-rise building – timber or not – needs to consider how to counteract a range of environmental hazards.

 

Many people also don’t realise that mid-rise timber buildings are externally clad to protect them from water damage and extend their effective life well beyond the mandatory 50 years specified by authorities.

 

Mid-rise timber apartment buildings offer domestic builders who are prepared to innovate and upskill their teams a wonderful opportunity to reach new markets on suburban sites which may not previously have been viable, to save on costs and to build in a much more environmentally friendly manner.