The Costs That Only Small Jobs Carry

The usual explanation for small jobs costing more per unit is that the labour is less efficient. That is true but it is the smaller half of the story, and the site’s own evidence says so: when the same tile specification is priced twice in the same price book, once for large works and once for small, the labour hours and labour cost are identical and the whole premium sits in the material.

This note collects the costs that behave that way: fixed per delivery, per visit or per job, invisible in any per-unit rate, and therefore heaviest on exactly the jobs a homeowner is having done.

Materials Are Priced for a Full Load

Price book prime costs assume a full load delivered to one notional address. Spon’s says so: “Part loads generally cost more than whole loads but, unless otherwise stated, Prime Cost figures are based on average prices for full loads delivered to a hypothetical site in Acton, London W3.”

It then publishes the penalty. For ready-mixed concrete:

That surcharge is 28.3% on the published rate. A domestic foundation pour of three cubic metres is a part load by definition, so no household job ever buys at the headline price. The same shape applies across merchant buying: full packs, full pallets and single drops are priced differently from the odd bag, and the published figure is nearly always the first kind.

This is the practical reason the small-works premium lands on buying rather than hours, and it is the one part of a small job where a homeowner can actually move the number: consolidate orders, take one delivery, buy full packs, and use a merchant account rather than a retail counter. Our note on reading a builders’ merchant quote covers the mechanics.

Access Is Excluded, and on Roof Work It Is Half the Job

Price book spot items for domestic repair state the exclusion on their face: prices “include for removal of debris from site but do not include for shoring, scaffolding or redecoration, except where stated.”

The chimney example is stark. Spon’s prices a full stack rebuild, 680 mm by 680 mm by 900 mm above roof, using 25% new facing bricks, new lead flashings, parged and cored flues and reset pots, at £451.88, with “scaffolding excluded” written into the item description itself.

Set that against a quotation that includes a chimney scaffold and you are comparing one number with roughly two numbers added together. Because access is a fixed cost per visit, it dominates a small job and almost disappears on a large one: the same scaffold that is most of a chimney repair is a rounding error on a full re-roof. Our note on scaffolding costs has the figures.

The same logic drives call-out and minimum charges, which are the trade’s way of recovering a fixed cost of attending when the work itself is small. They are not a markup on the work, they are the price of the visit.

Builder’s Work After the Trades Is a Separate Trade

Cutting away and making good after an electrician or plumber is measured in a different section, under a different trade, and no electrical or plumbing rate carries it. Spon’s prices it per point:

A modest rewire of 25 sockets and 15 lighting points carries about £330 of builder’s work sitting entirely outside the electrician’s figure, plus separate rates for every chase and every hole through a wall.

Set a trade quotation that excludes making good against a cost guide that includes it and the gap reads as the tradesperson being expensive. It is not: it is a second scope that somebody has to price, and the question worth asking any electrician or plumber is simply whether making good is in or out.

Percentage Fee Scales Stop Being Percentages at the Bottom

Professional fees are usually described as a percentage, and below a certain size that stops being true. The VOA scale charges 12% up to £750,000 and 11.5% from £750,000 to £1,500,000, but with a stated minimum fee of £90,000 on that second band.¹

Follow the arithmetic. Between £750,000 and £782,609 the fee is a flat £90,000, so the effective percentage slides from 12.0% down to 11.5% with no change whatever in the work. And below £750,000 the scale does not apply at all: the VOA’s own footnote says such schemes “would be charged on a time basis”.

So a £30,000 domestic job does not attract 12% of professional fees. It attracts however many hours the job takes, which on a small project is frequently a much higher proportion. Scaling a published fee percentage down to a small project is one of the most common ways a small-works budget goes wrong on the professional side, and it usually goes wrong in the optimistic direction.

What This Adds Up To

None of these costs are hidden in the sense of being concealed. Every one of them is published, most of them in the same documents as the rates they sit outside. They are simply not in the number, and the number is what travels.

Practical consequences:

1. A per-unit rate from a large job does not scale down. Expect the fixed costs to be a real fraction of a small job, not a rounding error.
2. Ask what is excluded, specifically. Access and scaffolding, making good after trades, and delivery or part-load charges are the three that most often sit outside a headline figure.
3. A minimum charge is not a markup. It is the fixed cost of turning up, and it is why splitting work into several small visits costs more than doing it in one.
4. Batch the work and batch the buying. Almost all of the saving available on a small job lives here rather than in the hourly rate.
5. Do not scale a fee percentage down. On a domestic project, ask for a fee on a time basis or a fixed sum, and expect the percentage to look higher than the published scales.

The underlying point is the one that runs through how a published rate becomes a cheque: rates describe work, and jobs contain a good deal more than work.