1. Four checks on a single figure
For every price per square metre presented. Four details are requested before it is used.
| Check | Why |
|---|---|
| Which completion level: shell, white box or turnkey | roughly a twofold difference |
| Which area, stated rather than assumed | sets the denominator of the fraction |
| Including VAT or not | the rate has moved from 20 % to 24 % |
| Which source, and of what date | distinguishes official from commercial |
Without these four the figure is not interpretable, and it should not be carried into a budget. They concern the area, the completion level, VAT and the date.
2. Five checks before preparing a budget
These concern the project, not the figure. They decide whether the figure applies at all.
| Check | Financial weight |
|---|---|
| Has a ground survey been done, or are reliable earlier data available | risk of oversized foundations |
| How far is the connection point from the substation | determines whether the charge is known in advance |
| Has the main fuse been sized against actual use | affects both connection and network charges |
| Are preparation costs on a separate line | €5,000 to €15,000 |
| Are external works in the budget from the outset | separating technical from aesthetic |
The second and third checks carry the most financial weight, because the connection is a four figure sum that can be partly influenced: the 400 metre line is a property of the plot, the size of the main fuse is a decision. Both fall outside the price per square metre.
3. Three checks when comparing quotations
Before starting to explain any price difference. Three assumptions are checked first.
Is the completion level the same.
Is the cost scope the same, that is do both include, or both exclude, preparation and connections. A different scope makes the comparison meaningless.
Is the area definition the same, where prices per square metre are being compared. A different area gives a different figure.
If one of these does not hold, the comparison measures a difference in content, not in price. In that case the quickest solution is to compare total cost rather than price per square metre.
4. Four checks on an older estimate
Where a figure that is not fresh is being used. It is updated with the index before use.
| Check | Why |
|---|---|
| Has the project changed in the meantime | the index updates a price, not a scope |
| Has the VAT rate changed | twice in two and a half years |
| Has the connection charge changed | the only one obtainable with a single enquiry |
| Which construction price index indicator applies | building group and type |
The first check is the most often skipped and the most consequential. It concerns the completion level.
5. What to do when something does not fit
Four situations and four answers.
| Situation | Answer |
|---|---|
| The completion level is unknown | ask for a list of works, not a term |
| The area is undefined | use total cost |
| The ground has not been surveyed | do not add a contingency, commission the survey |
| The connection is more than 400 m away | request a quotation, because it cannot be estimated |
The third answer is the most counter-intuitive and the one that saves the most money: not knowing costs more than the survey, because it leads to oversized foundations. A fresh comparison costs less than a wrong decision.
6. One sentence that sums up the guide
A price per square metre is good for a first order of magnitude and poor for deciding.
To decide you need to know what the price covers, which area it refers to, and what falls outside it. Those three things require asking, not calculating.
In summary, and four practical rules
Every price per square metre needs four checks before entering a budget, and every project five before a budget is prepared, of which the distance to the connection and the size of the main fuse carry the most financial weight. Comparing quotations requires three conditions to hold, and using an older estimate four checks, of which the most often skipped is whether the project itself has changed.
Four rules: carry into a budget only figures that have passed the first four checks. Check the project, not only the figure, before preparing a budget. Harmonise quotations before comparing, not after. Prefer knowledge to a contingency where the knowledge is obtainable.
This article serves professional orientation at the date of checking. It is not a quotation.