There is a mix of outside contractors and volunteer labour working on Temple Farm. The WTS is moving to use outside contractors for a number of reasons such as continuity of work, expertise, health and safety, costs etc.
It's easy to say that using volunteer labour reduces cost but if the project takes longer, has peaks and troughs of labour availability and involves overheads in accommodating these people then there are hidden costs that can be increased.
Health & Safety legislation on building sites is always being tightened and nowadays you typically need documentation to prove you are competent just to get on a site, let alone do things like operate certain machinery or work at height. The logistics of making this happen with your weekend warrior volunteer is very complicated. Much easier to pass the risk and responsibility onto a contractor.
The expertise required in large projects is increasing as well. Large groundworks, steel erection, modern building management and lighting control systems, facade systems, building code adherence etc. all require more skills than the WTS can be sure to have on tap at the right time. There's plenty of Bob the Builders in the congregations but not that many construction and engineering specialists with years of experience in large commercial building projects. That's not to say they are not there, just that having a contract in place means timescales can be more reliably followed and the right resource available.
The final factor is that they don't want huge numbers of elders, servants and pioneers out of the congregations. They want them there leading people and keeping the numbers up. There is no doubt that when a large proportion of the bright lights in a congregation get embroiled in a construction project then everyone else slacks off or get hacked off at the workload they are enduring just cos the COBE is off enjoying cushty days eating bacon sarnies and home made cakes on site.
