Here are two recent examples.

In the story about CEBR's estimate of 6,200 job losses in the City one gherkin equates to just over 3,000 City jobs.

In the story about the estimate by Drivers Jonas that there will be a tidal wave of excess office space in City one Gherkin equates to just shy of 1% of the total available office space in the City.

Who needs a pole, perch, rod or acre when you have the Gherkin. Let me know if you spot any other examples.

A fall of this scale would beat the 1974 drop of 24% in homes built for sale - the biggest post-War collapse in house building.

But more worrying to the industry as a whole is that he seems to be suggesting industry volumes will drop by a quarter this year. That is huge. It is as large as the peak-to-trough fall in the housing recession of the early 1990s.

I haven't seen the detail of the note yet and imagine there must be some nuance in the definitions, but if what he appears to be suggesting turns out to be close to what actually happens on the ground, then a construction recession this year suddenly looks much more likely. Which leads me to believe I am missing something.

But it is worth looking at the figures...

Each quarter their trade body FMB conducts a state of trade survey where it measures (among other things) the balance between those seeing workload rise and those seeing it fall. The figure for the first quarter of this year came in at -8 compared with +6 at the end of last year.

This sharp fall was perhaps predictable, as the fourth quarter 2007 survey had shown one of its worst ever figures for new enquires (a balance of -14).

Today we see released the spring Item Club economic outlook for business and the latest Rightmove figures on asking prices for housing. Both are substantially less confident about house price than at the start of the year. Rightmove has eased on its confident postition of a flat market this year and the Item Club has moved from its winter forecast position of a flat market to 5% falls this year and next.

But to comfort those who are unduly fearful, David Miles (one of the Morgan Stanley team forecasting a 20% real-term fall in house prices) writing in the Sunday Telegraph suggests this is not as frightening a prospect for most of us as we may fear.

Two figures are particularly worrying for the construction sector. Firstly: The balance of surveyors reporting demand down against those seeing demand rising was 30%, the worst figure for six years. Secondly: The balance between surveyors saying there was more available space against those reporting less was 27%, a rapid change from previous quarters when there was a fairly even balance.

Lending was up 5% on February, but the normal 20% March jump was absent with the figure 17% down on a year ago. Worse still is the likelihood that when the more detailed figures are released (splitting loans between house purchase, remortgage and other) they will show that lending for house purchases extremely muted.

This boost will be particularly welcomed by both the Chancellor and Prime Minister, as the employment figures are so far proving to be their strongest card in their quest to convince the nation that the UK economy is on a firm footing.

RealtyTrac also suggests that things are so bad that more defaulting homeowners are simply walking away and leaving their properties to the bank. Memories, and bad ones, come to mind of the early 1990s in the UK.

According to the latest monthly RICS housing market survey, the seasonally adjusted figure for the difference between the proportion of agents seeing house price rises and price falls was 78.5% in favour of those seeing a fall. That is much gloomier than February’s pretty gloomy figure of 64.1%.

So far so bad. But there are interpretations of these figures, fairly equally balanced, that might lead to a more pessimistic view on what the data means or a less pessimistic one, depending on what you want to focus on.

And certainly the contracting fraternity must be starting to sense a cold chill heading its way. The latest data has all been gloomy and the construction new orders figures for February suggest that the flow of work in the pipeline for both the housing and commercial sectors is easing.

The headline grabbing data from the US are disturbing - housing starts down 54% from the 2005 average and a 34% drop in the value of private house building since February 2006. These are not figures that would be welcome here in the UK.

Well the figures have been published and show a monthly fall of 2.5%, the fastest since September 1992. This was worse than expected and puts the March 2008 seasonally adjusted average house price at £191,556 against £194,094 last March. A fall of 1.3%.

So when the March results released today showed the index turning sharply negative, it was a clear sign that the shakes felt in the financial markets last Autumn are vibrating in the construction industry right now.

The main Index broadly measures the balance between those purchasing managers who saw activity expand and those who saw it shrink over the previous month and the March figure of 47.2 (against a no change mark of 50) was the worst for almost a decade.

The short answer is seriously concerned. But that is only a partial answer. It certainly does not address the fact that what seems like only yesterday there were plenty of experts predicting all manner of problems, with the industry by now in near meltdown swamped with work and bereft of talent.

The most fanciful of those predictions now look as they did at the time – fanciful. But they do provide object lessons in the need to contain hyperbole. And there is a real danger that too much might be read into the RICS survey.