Last updated November 6, 2026
Rules and figures from other sources checked on November 6, 2026. They change, so confirm with the source before you rely on them.
Expect about 70% of working time for a staff architect and just under half for a practice owner, going by RIBA's practice data. On a 37.5-hour week, 70% is about 26 hours. Set your own target by role, because a firm-wide figure hides who is actually earning the fees.
What is a realistic billable target for an architect?
A realistic billable target for an architect is about 70% of working time for staff, a little lower for associates and well below that for owners, because senior people spend more of the week running the practice. RIBA's white paper on practice management gives these averages:
| Role | Share of time on billable work | In a 37.5-hour week |
|---|---|---|
| Architects, technologists and assistants | Nearly 70% | About 26 hours |
| Associates | About 63% | About 24 hours |
| Partners, directors and sole principals | Just under half | About 18 hours |
The hours column is our arithmetic, not RIBA's. Size matters too: RIBA's benchmarking has put staff in practices of 100 or more above 80%, so a six-person studio shouldn't measure itself against that.
Why do architecture utilisation benchmarks disagree?
Architecture utilisation benchmarks disagree mainly because they divide by different things and sample different firms.
| Source | Figure | What it measures |
|---|---|---|
| AIA best-practice guide | 60% to 65% | Direct labour as a share of total labour, in money. The total includes paid leave and support staff |
| RIBA | Nearly 70% for staff | Share of time on billable work, by role |
| Monograph 2025 report | 81.1% average | Billable hours ÷ hours worked, across 527 firms of 3 to 30 staff using its software, filtered to rates of 50% to 100% |
Monograph is a software vendor and its sample is firms that already track time closely, which is worth bearing in mind. None of these is wrong. Pick one definition, write it down and measure the same way every month.
How do you calculate utilisation for an architect?
Utilisation for an architect is billable hours divided by hours available, and the choice you have to make is what "available" means. Here's an invented example: a UK architect on 37.5 hours a week with the statutory minimum of 5.6 weeks' holiday, ignoring sickness.
| Hours a year | |
|---|---|
| Contracted: 52 weeks at 37.5 hours | 1,950 |
| Less statutory holiday: 5.6 weeks | −210 |
| Hours available | 1,740 |
| Billable at 70% of hours available | 1,218 |
| Everything else | 522 |
Those 522 hours have to hold practice admin, proposals, meetings and, for a RIBA chartered member, 35 hours of CPD. Over the 46.4 weeks worked, 1,218 hours is 26.25 a week.
Now divide the same 1,218 hours by the 1,950 contracted hours and this architect reads 62%. Nothing about the week changed. That's part of the reason a 60% to 65% benchmark and a 70% one can describe similar firms.
Roles change the firm-wide number even more. Here's a small invented practice, with every person on target:
| Person | Hours available | Target | Billable hours |
|---|---|---|---|
| Director | 1,740 | 45% | 783 |
| Associate | 1,740 | 63% | 1,096 |
| Architect | 1,740 | 70% | 1,218 |
| Technologist | 1,740 | 70% | 1,218 |
| Part 1 assistant | 1,740 | 70% | 1,218 |
| Practice manager | 1,740 | 0% | 0 |
| Practice | 10,440 | 53% | 5,533 |
The practice reads 53% with nobody underperforming, so set and review the target person by person.
What counts as billable on a fixed-fee job?
On a fixed-fee job, billable means time spent on project work covered by the fee, even though the client never sees an hourly line. Some practices say "chargeable" or "project time" for that reason. Use the same categories for everyone:
| Activity | Count as billable? | Note |
|---|---|---|
| Stage work within the appointment | Yes | |
| Additional services agreed with the client | Yes | Log them apart from the stage |
| Rework after your own error | Project time, not recoverable | Log it where you can see it |
| Fee proposals and competitions | No | A practice cost |
| CPD, training, practice admin | No | |
| Travel to site | Depends on your appointment | See billing for travel time |
Utilisation counts hours, not money, and fixed fees are where that bites. Take an invented Stage 3 fee of £10,200, budgeted at 120 hours at £85. If it takes 150 hours, the team's utilisation looks fine, but those hours earned £68 each and the extra 30 cost £2,550 of charge-out time. The guide to budget hours vs actual hours shows how to catch that during the stage, and utilisation versus billable hours covers the wider measure.
How does billable time affect your hourly rate?
Billable time sets the hourly rate you need, because salary and overheads have to be recovered from the hours you can actually charge. Take an invented architect costing £52,000 in salary and on-costs, with £35,000 of overheads allocated to them, so £87,000 a year.
| Billable share | Billable hours | Break-even rate |
|---|---|---|
| 70% of 1,740 | 1,218 | £71.43 |
| 60% of 1,740 | 1,044 | £83.33 |
Ten points of utilisation moves the break-even rate by about £12 an hour, before any profit. The guide to calculating a charge-out rate takes it from there.
Working out billable time alongside ERPFlow
ERPFlow doesn't have a timer or timesheets today. Time tracking, including converting tracked time into invoices, is coming soon. ERPFlow also has no utilisation or per-person time reports, so the calculations in this guide stay in a spreadsheet, usually fed by a weekly timesheet layout.
Some of the inputs can come from ERPFlow:
- Time by project. A card in Projects has a time spent field, typed in as hours and minutes, and the totals add up per project and per customer.
- Exporting that time. The CSV export of cards gives you the title, project, column and time spent. Assignees aren't in the file, so it can't produce a per-person figure.
- Hours available. Each staff record has a calendar tab showing bookable hours, bookings, time off and public holidays. Vacations handles requests and approvals, though it doesn't calculate entitlement or accrual.