Pods: you know it makes sense!

The construction industry has been challenged by skills shortages, new regulations, environmental performance standards and a government drive to build more, and to better quality. Technical author, John Boanson, fresh from futurebuild2006, enthuses about pods, one solution to these challenges, and covered in NBS work section B11.

While most rooms are relatively easy to construct on-site, to site tolerances and quality, this is not so for your bathroom and kitchen. These require a level of quality and intensity of labour that the other rooms can live without. When considering buildings other than dwellings, labour intensive rooms crop up again and again, e.g. wet rooms, preparation areas, grouped accommodation kitchens and bathrooms.

Imagine a building contract without these labour intensive spaces on-site – surely anyone could construct on time, and maybe even on budget. Pods could be the way of achieving this.

Modern off-site construction is a far cry from the prefabs built in the 1950s and 60s with their notoriously poor standards (see NBS Journal 06, Book review). Off-site techniques offer benefits of time, quality, health and safety, and life cycle cost. We must consider all of these factors when judging innovative building techniques, not simply the basic cost of the units.

Pods can be constructed from concrete, fibreglass, steel (sandwich panels or frames), or timber. The walls are lined with particleboard or plasterboard and finished (internally) with tiled and/ or plastered walls and suitable floor coverings. Composite pods offer a highly robust and completely sealed glass reinforced plastic (GRP) unit.

Pod pluses

Pods can be factory assembled and delivered to site at a time required by the construction programme. Isn’t that a contractor’s dream? No more hoards of tradesmen trampling over each other to get access to the same restricted space, and no expensive components lying around on-site liable to be damaged or stolen. Just order your bathroom, have it delivered when you say so, and pay the price you agreed. Simple. You are buying a product not trying to construct one on-site. Just-in-time delivery of pods removes the need for costly on-site storage, too.

In addition to certainty of delivery time and cost, what extra benefits can pods offer? Pods reduce the number of tradesmen on-site, and those that are on-site are there for a shorter period of time. The quality and tolerances that can be achieved by factory production are very high. When did you last buy a brand new car that was built to a tolerance of 15 mm or worse? This is what we work to on-site for lots of trades. In factory-controlled conditions this would be laughable and totally unacceptable.

By using pods, you have the opportunity of building one to the exact standards you require. You can then keep this as a sample to test all other pods against. Quality guaranteed! It doesn’t have to cost more as you can always use this sample as the last pod installed.

Pods can be wrapped in the factory and only unwrapped the day before practical completion. You will be safe in the knowledge that they will be in exactly the same condition as when they left the factory. No need for final cleaning or touching up. More often than not they will also be defect free. What a dream – a newly constructed building without defects!

Where there is a risk of the unit being misused, the composite pod has distinct advantages for both specifiers and those responsible for the building’s maintenance.

If the unit is to be incorporated into a hospital, infection control is much simpler because all the joints are sealed and there are no unfinished corners that could provide a breeding ground for germs.

Finally, pods can be assembled so that they are ready to plumb in via a single umbilical connection that can often be fully commissioned in one hour of site work. Compare this with the many hours it would normally take to install and commission a bathroom.

So why aren’t we all using them? A downside

A word of warning to architects and designers: if you intend using pods, or any other type of prefabricated construction, you have to be organized. True, they will reduce the on-site construction time, but they might take up to 20 weeks to manufacture, particularly if you want a sample constructed. Get organized, discuss your design with the manufacturer and – most important – don’t change your mind once an order has been placed. This will be costly and waste a lot of time.

It is a common misconception that pods are expensive, but when you consider all of the benefits they can offer, they can be remarkably cost effective and can truly enhance the quality of your building.

Install a pod. You know it makes sense!

Written May 2006