Where an architecture firm’s margin actually leaks

The number you are trying to protect is getting smaller

Three organisations publish profitability benchmarks for this profession and they do not agree, because they measure different populations in different ways. It is worth seeing all three rather than picking the comfortable one.

The direction matters more than the exact figure. Deltek’s 47th annual study, published in May 2026 and covering 896 firms, recorded operating profit falling 4.7 points in one year while overhead reached a ten year high of 161.3 per cent. Backlog contracted from nine months to 6.3. That is a profession absorbing cost it cannot pass on.

Leak one: work you completed and never billed

Realisation is the share of the value of work performed that you actually collect. The published average is 83 per cent, with a typical range of 74 to 94 and high performers above 90. BQE puts the consequence plainly: the average firm leaves seventeen per cent of billable value uncollected.

That is not a rounding error. On a studio billing 600,000 a year it is roughly 100,000 of work that was designed, drawn, checked and delivered, and then quietly written off.

Leak two: hours nobody is paying for

Utilisation is the share of paid time that is chargeable to a project. BQE reports an average of 64 per cent. Deltek’s FY2025 figure is 58.9 per cent, down 2.2 points in a year. PSMJ, surveying 320 firms for the same period, reports 57.5 per cent. Whichever you take, something close to four in every ten paid hours is not billed to anyone. The utilisation and capacity planner works out yours on both the hours and the money basis, and what it implies for annual fee capacity.

What did correlate, in the same analysis, was workload. Firms with the highest backlog wrote down nearly three times more billable work and ran margins 8.2 points lower than their peers. Being busy and being profitable turned out to be close to opposites, which points the diagnosis somewhere uncomfortable: not at how efficiently you work, but at which work you agreed to do.

Leak three: scope that grew without a fee

A quarter of projects finish over budget. Deltek’s FY2025 data puts 75 per cent of projects on or under budget, which is the same sentence read from the other end. Across industries, the Project Management Institute found 52 per cent of projects experienced scope creep, up from 43 per cent five years earlier.

The cause shows up in the same Deltek study. Only 33 per cent of firms named a well defined scope among their top three project management strengths. Eighty per cent named client relationships. The thing practices are best at is precisely the thing that makes saying no difficult.

Leak four: the discount agreed in the room

A ten per cent discount does not cost ten per cent. At a typical margin it removes about half the profit on the job, because the cost of delivering the work does not move when the fee does. We have written about that arithmetic in detail, and the fee discount impact calculator will run it on the number actually in front of you.

Leak five: proposals that went nowhere

Deltek recorded proposal volume rising 32 per cent in 2025 while the capture rate by value fell 3.8 points to 44.4 per cent. The median win rate across all firms is 49 per cent, and for architecture firms specifically 45 per cent.

Read that as a cost. More than half of all the time spent writing proposals, assembling references, preparing fee breakdowns and attending interviews produces no fee at all. It is unbilled, it falls on senior people, and it is almost never costed. The cost per project and marketing ROI calculator turns spend, enquiries and conversion into a cost per won project, which is where that effort shows up.

Leak six: work finished, invoiced and unpaid

Here the published sources disagree sharply, which is itself the useful finding.

A spread that wide usually means the samples differ rather than that one is wrong. What is consistent is the scale: somewhere between seven weeks and ten weeks of completed, invoiced work is sitting unpaid at any moment, financed entirely by you. The late payment cost calculator prices that wait for your own fees and cost of capital.

Why this bites small studios hardest

Roughly 75 per cent of architecture firms have fewer than ten people, and 28 per cent are a single person. Those firms are not scaled down versions of large ones, they are structurally less profitable.

And the gap is widening. Between 2015 and 2023 the share of billings going to small firms fell by one half, while the share going to large firms rose by 40 per cent.

What actually moves the number

1. Stop treating busy as healthy. The firms with the most backlog wrote down three times more work and earned 8.2 points less margin. Capacity you have already sold is not a cushion, it is a liability if it was sold badly.
2. Cost a proposal before you write it. If you win 45 per cent of them, every proposal needs to carry the cost of the one you will lose. Decline the ones you would not want at full fee.
3. Name the scope in writing, then charge for the change. The profession is best at client relationships and worst at defined scope, which is exactly why additional services go unbilled.
4. Shorten the collection period before you raise the fee. Reducing days outstanding costs the client very little and returns cash immediately, whereas a fee rise has to be argued for.
5. Fix the pipeline upstream. Every leak on this page is easier to close when you have more qualified enquiries than capacity, because then you can decline work. That is a marketing problem wearing a finance problem’s clothes.