Call for greater standardisation and modularisation
In the face of seemingly endless increases in labour costs, greater use of standardisation and modularisation in pre-casting could offer the way out for the construction industry, according to a major building contractor.
Speaking last week at a conference on innovation in productivity and technology organized by the Construction Industry Council, Yau Lee Holdings (0406) vice chairman Conrad Wong Tin-cheung said standardisation of precast unit parts could reduce the learning curve time, offer economies of scale and allow re-use of tools and methods.
Hong Kong was already doing pre-casting and has been for several decades already but for Wong, this was not enough.
“If we look at other countries, like Japan, they are much more standardized than we are in Hong Kong,” Wong said.
In Japan, the precast industry was very much manufacturer driven and any designers who had other ideas would find themselves disappointed.
“Usually the precast industry will not welcome any non-standard design,” Wong said.
As the manufacturers worked in quantities of thousands, making only a few hundred units would not be economical enough.
Despite the higher cost per unit due to lower quantities, Yau Lee was still persisting in pre-casting as a solution.
According to the company’s latest annual report, segment sales in 2012 for precast units was HK$478 million, up 50 percent year-on-year, mostly to the company’s own projects.
Indeed, the annual report boasted: “We are now the largest precast manufacturer within the region.”
Wong mentioned to the 260-odd strong audience at the conference of the disbelief from Japanese and German manufacturers when they visited Yau Lee’s production facility in Shenzhen where the company was able to do complex designs at lower quantities.
He said a little push towards standardisation could help contractors a lot in items such as windows, door sizes, façade and curtain wall grids.
All this would help increase productivity, reduce labour costs and time for construction.
“This is maybe something the CIC could consider,” Wong said.
However to fully benefit from standardisation, modularisation of components was also required, as the example of the Housing Authority showed.
HA housing projects now have entire kitchen and bathroom units, staircases and even drainage U-channels with steel covers manufactured off-site.
Naturally there would have to be a trade-off between design and productivity as a result of using standard and modular precast units.
Still Wong said designers could do their bit to help contractors by greater adoption of modularization in construction.
Even if the units were manufactured by different suppliers, there would be no effect on productivity as workers would be familiar with installation.
“If you think along that way, the productivity increase will be enormous,” Wong said.
A comparison of insitu and precast was made by Wong.
With insitu construction in Hong Kong, only formwork, logistics and land costs were lower than precast in China.
Hong Kong in particular used cheaper timber formwork and there was literally no land cost as the work was carried out on the construction site.
China had lower labour costs but this was offset by the higher cost of steel formwork moulds and higher cost of logistics.
Material costs in Hong Kong and China, however, were about the same.
Wong said a precast steel mould had to be used 30 to 50 times before it was economically viable against insitu.
To illustrate Yau Lee’s commitment to precasting, Wong pointed to an example of the way it handled the construction of the roof area of HA housing blocks which usually housed plant rooms and lift machinery rooms.
It decided to use steel formwork instead of timber and made use of precast units.
“We managed to cut down about one month [worth] of construction time using less labour force,” Wong said.
However the total cost was higher because there wasn’t enough repetitiveness to become cost attractive.
Building Information Modelling (BIM) was mentioned by Wong in his speech where he touched on the usual benefits of using BIM such as crash analysis, production scheduling, safety planning and cost.
Caution however was required especially in crash analysis.
If BIM showed a crash, then there would be crash on site.
Having no crashes in BIM, however, did not guarantee no crashes on site.
“[It’s] because of construction work tolerances. So do not 100 percent rely on BIM models,” Wong said.