The total is the least useful number
A cost plan is read by people who want one figure, and that is the figure they take away. It goes into an appraisal, then into a board paper, then into a funding pack, and by the time it has been repeated four times nobody remembers what it was based on.
The total is the least informative part of the document. Two surveyors measuring the same drawings will land close to each other. What separates a usable cost plan from a dangerous one is whether it states the boundary of what it covers, because everything outside that boundary is still going to be paid for by somebody.
The habit worth building is to read the exclusions first and the total second. If the exclusions are missing, the total has no meaning and the document is a quotation for an unstated scope.
The document has a second life nobody plans for. It gets forwarded. A cost plan prepared for an internal decision ends up attached to a funding application, then to a joint venture paper, then quoted back at you by somebody who never saw the covering email that explained it. Anything the document does not say about itself is lost at the first forward.
What has to be stated
Four things, at minimum. What is excluded, meaning work that will happen on this project and is not in this figure. What is assumed, meaning conditions taken as true without evidence. The basis of pricing, meaning the date and source of the rates. And the design information the plan was measured from, listed by drawing number and revision.
Exclusions are the ones people notice missing. The usual candidates are site abnormals, statutory service connections and diversions, planning obligations, fit out beyond shell and core, loose furniture, professional fees, finance and value added tax. Some of those belong outside a construction cost plan legitimately. None of them belong outside the appraisal.
The design information list matters more than it looks. A plan measured from a general arrangement at one revision, priced against a specification at another, and issued a month after both were superseded, is describing a building that no longer exists.
Assumptions are not exclusions
An exclusion says this cost is not in here. An assumption says this cost is in here, at a level that depends on something nobody has established yet. The second is more dangerous because it is invisible in the total.
Typical assumptions carry real money. Ground conditions taken as suitable without a survey. An existing structure assumed adequate for the new loading. A single crane position assumed workable on a constrained site. A programme assumed to be continuous with no seasonal shutdown. Each of those is a bet, and each has a value attached to being wrong.
The useful discipline is to write beside every assumption what would establish it and what it costs to find out. Most of them are resolved by a survey costing a fraction of the exposure.
Why it gets left out
Rarely through carelessness. More often because the exclusions list is the part of the document that generates awkward conversations, and a plan that arrives with a clean total is received better than one that arrives with two pages of caveats.
There is also a fee pressure. Establishing exclusions properly means asking questions of the design team and the client that take time to answer. A cost plan produced to a low fee is produced from what was supplied, and what was supplied rarely includes the awkward parts.
How a funder reads it
A lender or a monitoring surveyor testing your cost plan looks for the boundary before the total. They are trying to establish whether the facility covers the whole cost of getting to a saleable building, and a cost plan that quietly excludes service connections and section 106 obligations does not answer that question.
Where the exclusions are stated and the assumptions are listed with values, the conversation is short. Where they are not, the funder assumes the worst and prices the uncertainty into the facility, which is a slower and more expensive way of reaching the same place. We covered the funding side in reading a borrower’s cost plan.
What this means for you
Ask for the exclusions and assumptions as a separate page, not buried in a preamble, and ask for a value against each assumption. If neither exists, the document is a number rather than advice.
Then ask one further question: what would have to be true for this figure to hold. A surveyor who can answer that has thought about the scheme. One who cannot has priced a drawing. That distinction is the whole of what a client side quantity surveyor is for, and it is why we set the boundary on the face of every plan we issue through cost planning and estimating.
One test settles it quickly. Take the cost plan total, add every excluded item at a sensible figure, and compare the result with the number sitting in your appraisal. If the two are far apart, the appraisal is running on a construction cost rather than on a development cost, and the difference has to come from somewhere before completion.