Architecture Bookkeeping Small Business

Work in Progress: The Studio Number That Explains Why "Busy" Isn't "Paid"

Published August 24, 2026 by Invisible LLC Team · 9 min read

You went to design school. You did not sign up to be the CFO of a five-person studio.

But here you are, on a Sunday, looking at a schedule that is completely full, a pipeline that looks better than it did in the spring, and a bank balance that has not moved in six weeks. Everyone is working. Nobody is idle. And somehow there is less money than there should be.

That gap between "busy" and "paid" is not a mystery. It has a name, it has a number, and most studios never put it on a page.

The short version

Work in progress (WIP) is the value of the work your team has already performed but has not yet invoiced. It is real economic value your studio has earned and is currently financing out of its own pocket. When WIP grows faster than your billing, your studio gets busier and poorer at the same time — which is exactly the condition the market is handing architecture firms right now.

The fix is not a new system. It is a fifteen-minute weekly habit and one column added to the way you already track projects.

What work in progress actually is, in studio terms

Forget the accounting textbook for a second. Here is WIP the way it actually shows up in a practice.

A client signs a B101. Your team starts schematic design on the 3rd. You bill at the end of the phase. It is now the 24th, the phase is roughly 70% done, and you have not sent an invoice — because the phase is not finished, because that is how you have always billed.

Every hour your team has logged on that project since the 3rd is work in progress. You have paid salaries for it. You have paid rent on the desks where it happened. You have paid the payroll taxes on all of it. The client has paid you nothing, because you have not asked.

WIP is the money you have already spent to earn revenue you have not yet requested. It is the studio equivalent of a contractor buying all the lumber before the first draw.

Two related numbers sit next to it, and it is worth naming them so they stop being confusing:

Unbilled WIP — earned more than you have billed. This is the common one and the one that hurts. You are the bank.
Overbilling — billed more than you have earned, usually from a healthy retainer or a big deposit. This looks like a cash win, and it is, but it is borrowed from your own future labor. Spend it like it's profit and the back half of the project has no cash behind it.

Most principals feel unbilled WIP as a vague sense that the numbers are "behind." Putting a dollar figure on it converts a feeling into a decision.

Why this is the number to watch in the back half of 2026

The AIA/Deltek Architecture Billings Index came in at 46.6 for July 2026, released on August 19. Any score below 50 means the majority of firms reported declining billings, and July's reading was down from 47.3 in June. Business conditions have now been soft long enough to make this the longest downturn in the index's history — a series that has been running since 1995 (AIA, Architect's Newspaper).

But the headline is not the useful part. The shape of the release is.

Inquiries into new projects rose again in July. The value of newly signed design contracts fell further.

Sit with that for a second, because it describes a very specific and very dangerous operating condition. More people are calling. Fewer of them are signing. Which means:

Your team spends more hours on pursuits, proposals, and "quick studies" that never convert.
Projects that do sign take longer to get to a countersigned agreement — while the client, who is in a hurry, asks you to "start looking at it."
Your pipeline report looks better than last quarter, which makes it feel like the wrong time to slow down and chase invoices.

Every one of those is a WIP generator. A soft-contract market does not usually announce itself as a cash crisis. It announces itself as a busy studio with a stubbornly flat bank account.

How to calculate WIP for a project (the four-line version)

You do not need a WIP schedule that a surety company would accept. You need four numbers per active project, updated weekly.

Contract value for the current phase — what you will invoice when this phase completes.
Percent complete — your honest estimate of how much of that phase is done. Hours burned against the fee budget is a reasonable proxy for most design work; principal judgment beats the spreadsheet when they disagree.
Earned to date — contract value × percent complete.
Billed to date — what you have actually invoiced on that phase.

Then:

WIP = Earned to date − Billed to date

A positive number is unbilled work you are financing. A negative number means you are ahead on billing.

Run that across every open project and total the positive column. That total is the amount of your own capital currently parked in work you have already done. For a lot of five-to-fifteen person studios, the first time they calculate it, the number is somewhere between one and two months of payroll — and nobody had any idea.

The percent-complete estimate is where principals get nervous, and I want to take the pressure off: it does not have to be precise to be useful. A consistent, roughly-right estimate reviewed every week will change your decisions. A perfect estimate calculated once a year will not. If you have already set up job costing in QuickBooks, you have most of the raw material for this already.

The three places studios let WIP pile up

In practice, unbilled WIP almost always traces back to one of three habits.

1. Phase-end billing on long phases

Billing at the end of a phase is clean and easy to explain to a client. It is also a cash-flow decision, and most studios have never treated it as one. A CD phase that runs fourteen weeks means fourteen weeks of payroll before a single invoice goes out.

The fix is not to abandon phase billing — it is to bill within long phases. Monthly percent-complete billing against the phase fee is standard, defensible, and something clients see constantly. If your agreement allows it, this one change can pull weeks of cash forward. Our guide to AIA billing with G702 and G703 walks through the mechanics.

2. Reimbursables that lag the work

Printing, models, travel, consultant pass-throughs. The expense hits your card in March. The receipt lives in a jacket pocket. It gets invoiced in June, or it never gets invoiced at all. Reimbursables are a small share of fee and an outsized share of leaked margin, and they are pure WIP the entire time they sit uninvoiced.

3. Additional services performed before the change order

This is the expensive one. The client asks for a third option. You produce the third option, because you want the project to be good and you do not want the conversation. The extra work is real, it consumed real hours, and there is no signed authorization behind it — so it is not just unbilled WIP, it is WIP that may never become an invoice at all.

The discipline that fixes this is unglamorous: the additional-services conversation happens before the work, not at the end of the phase when you are reconciling hours and feeling resentful.

The weekly WIP routine

Fifteen minutes, once a week, same time every week.

Pull hours by project for the week. If time entry is not current, nothing downstream works — this is the one non-negotiable input.
Update percent complete on each active phase. Principal judgment, not just the burn rate.
Flag every project where WIP exceeds one month of that project's fee run-rate. These are your action items, not your whole portfolio.
Send what can be sent today. Percent-complete invoices, reimbursables, approved additional services. Most studios find something invoiceable every single week once they look.
Note anything that cannot be billed and why. Waiting on a countersigned agreement, waiting on a change order, waiting on a consultant invoice. The "why" column is where you will find the pattern that is actually costing you.

One clarification worth making, because it trips people up: your monthly financial statements and your WIP report are answering two different questions. The statements tell you what the practice earned. The WIP report tells you what the practice is owed but has not asked for. A studio can look profitable on paper and still be unable to make payroll, and the distance between those two facts is measured in WIP and receivables. That is the same reason project margin and firm margin tell you different things.

If you want the accounting term for what you are doing here: recognizing revenue as the work is performed rather than when the invoice is sent. It matters for your year-end statements and your CPA will care about it. But you do not need to master the terminology to run the routine — you need the routine.

When WIP turns into a cash problem

WIP is one leg of a longer trip. Work gets performed, then invoiced, then collected. Each leg adds days, and they stack:

Days of unbilled work + days until you invoice + days until the client pays = how long your studio finances every project.

Cut days out of any leg and cash arrives sooner. The first leg is usually the cheapest to fix, because it is entirely within your control — no client conversation required, no collections call, just billing the work you already did.

The second leg is often worse than principals think. Work finishes on the 28th, the invoice goes out on the 12th of the following month because that is when someone had time, and on net-30 terms the client pays around the 12th of the month after that. Six weeks of float created by internal scheduling alone.

If your studio is carrying more than about a month and a half of fee in unbilled WIP, or if you cannot answer "how much have we earned but not billed?" within a few minutes, that is the signal to put a real reporting rhythm behind it rather than reconstructing it by hand each quarter. A chart of accounts built for a studio rather than a tax return makes this dramatically easier, and utilization and realization rates tell you whether the hours going into WIP were worth the fee in the first place.

What to do with this

The market handed architecture firms a specific problem this summer: more inquiries, fewer signed contracts, softer billings. The studios that come through it in good shape will not be the ones that landed the most work. They will be the ones that converted the work they already did into cash faster than their peers.

That is a WIP question, and it is answerable this week.

We handle phase billing, reimbursables, job costing, and monthly project-level reporting for architecture and design studios — so the invoice goes out when the work is done, not when the principal finds a free Sunday. Our bookkeeping service keeps the ledger current and our business intelligence work turns it into a WIP and margin report you will actually read. You can see how we work with design and architecture practices, or request a quote and we will take a look at your current billing cycle.