Architectural Competency vs Detail Design

  • Building Design Expert
  • 5 years ago

After two or three decades of continually refining and producing detail construction designs one tends to get an intuitive feel for the adequacy and effectiveness of those same drawings published by other architects, or architectural practices. Looking at the drawing, one can deduce whether it’s author really has a clue how to communicate a design detail, or in fact understands the basic principles of construction and facbrication. Harsh perhaps, but true nonetheless.

So when I received a PDF of what I later learned had become a ‘standard detail’, and had in fact been used for construction purposes on a number of different projects; I struggled to believe it had been issued by a nationally renowned architects practice. It was a roof section detail. The particular area of roof involved had originally been designed for an uninsulated area of the building in that it was a cantilever over an external space. Subsequently the the building owner had decided that this space would be right to extend into. In theory no problem. All the architect had to do was acknowledge all the building regulations in force today and apply them to the new space. Well at least they tried.

The greatest problem was that the structure had never been designed to cover an internal space. It had been designed as an integral part of the adjacent structure that enclosed the original building, and formed a key architectural profile to the building itself. Have you guessed what it is yet?

If it developed any slight leaks over the original external area, whilst it may have generated one or two maintenance issues, nobody was going to get too excited. So the key challenges in the design were to:

1. Make the new internal space weather tight.
2. Insulate the existing roof

Of course the walls and floor would be new, so relatively little problem there.

So who came up with the detailed design solution that found it’s way onto my screen? Well, it could have been the office cleaner, or receptionist. One thing I am certain about is that it was not anyone who understood what the problems were and had tried to resolve them.

They did understand that perhaps a sarking membrane would help keep the weather out. But the fundamentals of it’s specific function were not catered for. Assuming it did manage to collect some wind driven water that had got past the tiled roof covering; the water had absolutely nowhere to go. It was actually destined to build up in a neat well created at the bottom of the pitch until presumably the volume and pressure of the accumulation was such that it percolated into the building above the window line.

Insulation? Oh yes we need insulation don’t we? Do we? How much do you think we need then? – Well of course the answer is to meet a specific U-value performance identified for the roof element in the building regulations relating to extensions. So how about if we throw in say 50mm of foam board then? Will that do the job?

The design of insulation products has come along way in a very short time, but sadly the performance of insulating foam board has not reached the sort of heights where 50mm is even close to cracking the nut. Oh, and don’t even ask where the condensation is likely to occur. No, but somehow this design has been created in an architects office. Issued to an Approved Inspector, who has presumably passed it as part of an application, and made it onto a minimum of a half a dozen building sites where it’s been constructed as best the contractor can, left to his own devices with no site inspections.

Of course it is unlikely there will be any problems straight away. It may well take a year or two of dripping condensation and driving rain and snow before the construction is found out. But then the contractor will have moved on, had a change of personnel. The as built drawings won’t be worth a light mainly because there won’t be any. The one thing there will be though is that design detail. The cleaner or receptionist that produced it may well have moved on also, but the red faced architect who pulls it up on screen from the archives may have a weekend or two curtailed as a result.

Imagine, if you will, the reality here. The chain starts  with a project leader delegating what might appear to be a relatively straight forward detail to a junior member of the architectural staff, who he thinks should be experienced enough to sort this particular problem out. The draft detail is put onto his desk for comment prior to inclusion with the other layout, elevation type information. But he’s called away to a meeting. By the time he returns, the pressure to issue the drawing pack has become huge. He takes a look at the detail and the majority of lines appear to be the right place. “OK, send this out to the contractor for pricing and the approved inspector because time is short”.

So this errant design detail has deftly slipped past the experienced project leader. It’s on the approved inspector’s desk, as the next line of defence. HOW does he miss it? Maybe he was in the same meeting as the project leader! So then onto the contractor’s estimating department. Now they, in fairness, are not paid to care whether it complies with any construction standards, or the building regulations. Just the price please Mr contractor. They could have said it was a lot less than normal because of the lack of insulation, unless, of course they just kept the price the same. OK I’m guessing here, I don’t really know.

I put this scenario to a former employer. He was adamant that there were enough safe guards in place in his office to ensure that a similar occurrence would not happen. He did not say “could” not happen.

It is unfortunately a sad reflection on a common reality that, possibly due to a ‘just in time’ culture, a professional who has his or her degree in architecture, or architectural technology has not received the academic training that would allow them to have a running start at designing the ‘nuts and bolts’ of our buildings as they enter the profession for real. For while their piece of paper from university may be proof of their Architectural Competency, there is no automatic installation of the ability to pick apart a building into it’s constituent elements to ensure it can go together on site in the simplest and most straight forward manor. That, unfortunately takes a decade or three.