Building Codes and safety standards have come a long way in the past century but that’s no reason to write-off an existing building as too hard to bring up to contemporary standards, according to Umow Lai director, Ken Loh.
The crucial starting point from an engineering point of view is understanding what the building will be re-used for, he explains. Then you need to understand a building’s existing conditions, including physical and operational conditions.
In planning and designing the re-love, it’s not sustainable to rip everything out, he says.
Knowing the existing conditions and the goal means being able to identify what can be re-used, repurposed or upgraded, and what absolutely needs replacing.
“Most existing buildings have good structural bones,” Loh says. “But many services such as HVAC and lighting have limited lifespans.”
Lighting has also “come a long way”, with LED making “huge leaps and bounds” in energy-efficiency, safety, colour temperatures and smart control systems.
This means lighting has a significant part to play in re-loving a building, but Loh says this does not mean it has to cost a lot.
“There is also no major impost in terms of space [occupied by smart LED lighting systems].”
One of the flow-on effects of upgrading to smart, energy-efficient lighting when installing the latest technology in an old building is that it will potentially use less electricity than the existing system, which means there may not be a requirement to increase the capacity of the building’s electrical systems.
While some types of buildings are more energy intensive, such as data centres, Loh says in general, commercial and multi-residential buildings have become less energy intensive than they were in the past.
You can also retrofit renewable energy such as solar PV, in the form of rooftop panels and advanced solar products, such as high-performing solar glass and solar facade panels.
Loh points out that while internal looks can change with a re-love, such as ceilings, ceiling space and the building envelope, the roof and the structure won’t.
Facades often need upgrading to a high-performance facade to achieve the required code compliance.
But the upside of facade retrofits for higher performance is that there is less need to increase active systems such as mechanical heating and cooling.
“It’s going in a circle,” Loh says.
A high-performance skin comprising a tighter building envelope with less air leakage and improved energy-efficiency from blocking heat is achievable.
Loh says a re-love will ideally “spend a bit more on the envelope” to reduce the need for active systems and the corresponding payoff of lower maintenance requirements, less space used for HVAC and, in turn, potentially higher NLA and useable space for occupants.
“Spend money where it matters,” he says.
Design trends like suspended ceiling lights and exposed, smaller HVAC ductwork can also help achieve more space in the form of height – which then means more of a sense of light and air in the space.
Loh says no single type of HVAC system works better for a re-love.
“It depends on the needs of the occupants and the type of building it will become.”
Underfloor systems can work where there is an existing false floor or one can be added. Chilled beam is popular because it can be suspended from an exposed ceiling.
The main guiding imperative is “how much occupant comfort you want to have,” Loh says.
One of the big wins a re-love gains from modern technology is in the communications and ICT infrastructure domain. Wireless technologies mean it is no longer necessary to run as much copper cabling to each workstation for phones and computing, which saves on materials, pathways and cabling space.
Loh says it is also easy to retrofit optic fibre, no matter what era a building belongs to.
Fire engineering can be tricky because “architects want to open spaces up, and fire engineers want to compartmentalise them”.
A campus-style internal layout with connecting stairs is popular for commercial, health and education buildings because it encourages interaction. Stairs are needed for evacuation and safety and can also be part of a connectivity and collaboration strategy.
Loh says slabs can be opened up to create more vertical space, but it will mean the fire engineer has to have their thinking cap on.
The single biggest constraint for a re-love project is whether there is a change of use. This raises some fundamental questions.
“If you repurpose a commercial building to, say, an apartment hotel, the bones are generally good and the structure is generally good, but you need more services,” Loh says. That means more hydraulics to service the numerous extra bathrooms, for example.
Converting accommodation to commercial also has challenges – including what to do with all the extra bathrooms and amenities.
When converting a commercial building to a teaching and learning building occupancy rises, Loh explains.
Students also have a different occupant pattern in terms of movement within the building, and this has implications for evacuation measures, fire protection and vertical transportation.
While it is extremely difficult to retrofit a new lift core to move more people, Loh says it is possible to modernise existing lifts and make them faster, and install technologies such as destination control that move people more efficiently.