Running an architecture firm means managing an intellectual services business with specific constraints: often lump-sum fees, long project cycles, fluctuating workload, and heavy dependence on each team member's time spent. In this context, intuition isn't enough. You need reliable, quantified indicators tracked over time.
Yet the majority of firms with fewer than 20 employees don't have a real management dashboard. Decisions are made "by feel," warning signals arrive too late, and fees for upcoming projects are calibrated based on impressions rather than data. The Archigraphie survey by the French Order of Architects confirms it year after year: average net margins of French firms remain low, often below 5%.
This guide presents the 7 key ratios that allow a firm principal to manage their practice with rigor. For each one: the definition, the formula, industry benchmarks, measurement method, and pitfalls to avoid.
The 7 Key Ratios to Manage Your Architecture Firm
A management ratio only has value if it meets three conditions:
- It is measurable -- the underlying data exists and can be collected reliably.
- It is comparable -- it can be compared to industry benchmarks or your own historical data.
- It is actionable -- reading it triggers a concrete decision (course-correct a project, hire, adjust a quote).
The 7 ratios presented here meet all three criteria. They cover the entire value chain of a firm: from human resource utilization to commercial conversion, through project profitability and effective billing. And all of them, without exception, rely on one fundamental piece of data: time spent.
Ratio #1 -- Utilization Rate (or Occupancy Rate)
Definition
The utilization rate measures the share of a team member's available time actually devoted to productive tasks (project work). It's the most fundamental indicator of human resource utilization in a firm.
Formula
Utilization rate = (Productive hours / Available hours) x 100
Available hours correspond to contractual working time, excluding paid leave, public holidays, and absences. For a full-time employee in France, this is generally between 1,540 and 1,607 available hours per year (depending on the collective agreement and company agreements).
Industry Benchmarks
| Level | Utilization rate | Interpretation |
|---|---|---|
| Optimal | 75 -- 85 % | Healthy workload, margin for contingencies and development |
| High alert | > 90 % | Risk of overload, burnout, zero room for maneuver |
| Low alert | < 70 % | Underutilization, commercial or organizational issue |
Measurement Method
The utilization rate is calculated per team member and per period (week, month, quarter). It requires reliable tracking of time spent on projects. Without time tracking, this ratio cannot be estimated.
Recommended frequency: Weekly for operational monitoring, monthly for management reporting.
Pitfall to Avoid
Pitfall to avoid: Counting all hours present in the office as "productive." Internal meetings, administrative time, email responses, regulatory monitoring -- all of this is necessary, but it's not billable to a project. A team member present 40 hours per week isn't productive for 40 hours. If you count everything as productive, your utilization rate will be artificially inflated and your actual hourly cost will be underestimated.
Ratio #2 -- Productive / Non-Productive Hours Ratio
Definition
This ratio refines the utilization rate by breaking down total time between hours billable to projects (productive) and non-billable hours (non-productive). It identifies the time structure within the firm and detects organizational drift.
Formula
Productive ratio = (Project hours / Total hours worked) x 100
Non-productive hours typically include:
- Administration: accounting, HR management, procurement, general correspondence
- Commercial: prospecting, bid responses, non-billable client meetings
- Training: technical monitoring, continuing education, conferences
- Management: firm meetings, reviews, internal coordination
- Downtime: between projects, waiting for project owner validation, IT failures
Industry Benchmarks
| Level | Productive share | Interpretation |
|---|---|---|
| Optimal | 70 -- 80 % | Good balance between production and overhead |
| High | > 85 % | Risk of neglecting commercial work and training |
| Low | < 65 % | Overhead too heavy or lack of projects |
Key figure: In well-managed architecture firms, the non-productive share represents about 20 to 30% of total time. This isn't "wasted" time: it's the time necessary for the business to function. The problem arises when this share exceeds 35%, a sign that the organization is consuming too many internal resources.
Measurement Method
This ratio requires categorizing every hour worked: either on an identified project or on an internal category (admin, commercial, training, etc.). It's this granularity that makes it valuable -- and that makes a simple spreadsheet insufficient over the long term.
Recommended frequency: Monthly per team member, quarterly for the firm's overall view.
Pitfall to Avoid
Pitfall to avoid: Treating non-productive hours as a problem to eliminate. Responding to tenders takes time. Training the team is an investment. Managing is working. The ratio isn't a tool to "punish" non-billable time, but to quantify it and ensure it stays within healthy proportions.
Ratio #3 -- Average Loaded Hourly Cost
Definition
The average loaded hourly cost represents what one hour of productive work actually costs the firm, all expenses included. It's the cornerstone of all project profitability calculations. If this ratio is poorly evaluated, all fee estimates derived from it will be wrong.
Formula
Loaded hourly cost = (Gross payroll + Employer charges + Overhead) / Total annual productive hours
Overhead includes:
- Rent and property charges
- Professional indemnity and decennial insurance
- Software licenses (AutoCAD, Revit, SketchUp, etc.)
- Computer equipment (depreciation)
- Travel expenses
- Accounting and legal fees
- Professional body dues
Industry Benchmarks
| Firm size | Average loaded hourly cost | Source |
|---|---|---|
| Solo / 1-2 people | EUR 38 -- 45/h | CNOA estimates |
| Firm 3-10 people | EUR 42 -- 50/h | UNSFA management surveys |
| Firm 10-25 people | EUR 48 -- 55/h | Archigraphie data |
| Firm > 25 people | EUR 52 -- 65/h | Varies by specialization |
Key figure: The average loaded hourly cost of a salaried architect in France is around EUR 45/h for a mid-level profile (5-10 years of experience), including charges and overhead. This figure is consistent with data published by the CNOA and specialized management studies.
Measurement Method
The calculation is done once or twice a year, based on accounting data (payroll, charges, overhead) and total productive hours achieved. The denominator is crucial: it's productive hours, not total hours worked. This is where the link with ratio #2 becomes evident.
Recommended frequency: Semi-annual or annual, recalculated with each hire or structural change.
Pitfall to Avoid
Pitfall to avoid: Forgetting to include overhead in the calculation. Many firms calculate their hourly cost based solely on "gross salary + charges," omitting rent, insurance, software licenses, and equipment depreciation. The result is an hourly cost undervalued by 15 to 25%, which systematically skews fee estimates. A firm that estimates its hourly cost at EUR 35/h when it's actually EUR 47/h loses EUR 12 on every hour worked -- without even knowing it.
Ratio #4 -- Profitability Rate per Project
Definition
The profitability rate per project measures the margin generated on each commission, relative to fees received. It's the central indicator for knowing which projects "make money" and which lose it. In an architecture firm, profitability gaps between projects can be considerable: one project may deliver 25% margin while another loses 10%.
Formula
Profitability rate = (Fees received - Actual hour cost) / Fees received x 100
Where: Actual hour cost = Hours consumed x Loaded hourly cost (ratio #3)
Industry Benchmarks
| Level | Profitability rate | Interpretation |
|---|---|---|
| Good | 20 -- 25 % | Well-calibrated and well-managed project |
| Acceptable | 15 -- 20 % | Decent margin but no reserve |
| Critical | < 10 % | The project absorbs resources without generating value |
| Negative | < 0 % | The project costs more than it earns |
Key figure: According to management analyses of French architecture firms, the average net project margin falls between 10 and 15%, but with very high dispersion. Firms that track their time by MOP phase show margins 5 to 8 points higher than those that don't.
Measurement Method
The profitability rate should be calculated phase by phase, not only at project close. Waiting until closure to measure profitability means observing damage without being able to correct it. Phase-by-phase tracking identifies drift by the end of APS or APD and allows trajectory adjustment for subsequent phases.
The calculation requires two pieces of data: hours actually consumed (through reliable time tracking) and the loaded hourly cost (ratio #3). Multiplying hours by the hourly cost gives the actual cost, which is compared to the phase fees.
Recommended frequency: At each phase end, and during the phase for at-risk projects (bi-monthly or monthly review).
Pitfall to Avoid
Pitfall to avoid: Measuring profitability only at project closure. When you discover during the AOR phase that a project is loss-making, there's nothing left to do. Phase-by-phase tracking is the only way to intervene mid-course: refocus the team, negotiate an amendment with the project owner, or arbitrate resources between remaining phases.
Ratio #5 -- Quote-to-Project Conversion Rate
Definition
The conversion rate measures the percentage of quotes or bid responses that convert into signed projects. It's an essential commercial indicator, but also a profitability indicator: responding to a tender costs time (often between 20 and 80 hours for an architecture competition), and this time is rarely recovered.
Formula
Conversion rate = (Signed projects / Quotes or bids submitted) x 100
Industry Benchmarks
| Level | Conversion rate | Interpretation |
|---|---|---|
| Good | 30 -- 40 % | Relevant targeting, well-calibrated proposals |
| Average | 20 -- 30 % | Common result, room for improvement |
| Low | < 20 % | Poor targeting, unsuitable proposals, or excessive competition |
Key figure: In architecture, a conversion rate of 25 to 35% is considered normal for private sector projects. For restricted public competitions, the rate is structurally lower (15-25%) due to competition and the selection process. The key is to measure the acquisition cost: how many non-billable hours are invested to win a project.
Measurement Method
It's essential to track two elements in parallel:
- The number and outcome of each commercial proposal (signed, lost, no response).
- Time spent on each response -- prospecting, site visits, proposal preparation, presentations.
Crossing these two data sets allows you to calculate an acquisition cost per signed project. If a firm spends an average of 50 hours per response and signs one proposal in four, each signed project cost 200 hours of non-billable commercial time. At EUR 47/h loaded, that's EUR 9,400 in acquisition cost per project.
Recommended frequency: Quarterly, with an annual review of the commercial pipeline.
Pitfall to Avoid
Pitfall to avoid: Not accounting for time spent on unsuccessful bids. This time is real, it mobilizes team members who could be working on billable projects. Ignoring it means underestimating the firm's actual commercial cost and skewing the productive/non-productive hours ratio (ratio #2).
Ratio #6 -- Revenue per Employee
Definition
Revenue per employee is an overall productivity ratio. It compares the firm's annual revenue to the number of full-time equivalents (FTE). It's a synthetic indicator that allows comparison with similarly-sized firms and tracking of productivity trends over time.
Formula
Revenue per employee = Annual revenue excl. tax / Number of FTEs
The FTE count includes all employees (including the managing partner if compensated), apprentices (pro-rated for their time), and regular freelancers (converted to FTE based on their hourly volume).
Industry Benchmarks
| Firm size | Average revenue/FTE | Source |
|---|---|---|
| 1-3 people | EUR 55 -- 70K | Archigraphie / CNOA |
| 4-10 people | EUR 65 -- 85K | UNSFA surveys |
| 11-25 people | EUR 75 -- 95K | Industry data |
| > 25 people | EUR 80 -- 110K | Varies by specialization |
Key figure: The average revenue per FTE in French architecture firms is around EUR 72,000, according to the latest data from the Order of Architects. Specialized firms (healthcare, industrial, major facilities) show higher ratios, reflecting higher unit fees on these project types.
Measurement Method
Revenue per FTE is calculated over the complete financial year. To avoid distortions, it's preferable to smooth over a rolling 12-month period rather than taking a snapshot. Also watch for threshold effects: a mid-year hire increases FTE count before revenue has caught up.
Recommended frequency: Annual, with quarterly tracking during growth or recruitment periods.
Pitfall to Avoid
Pitfall to avoid: Comparing this ratio between firms without accounting for team structure. A firm composed mainly of senior project managers will have a high revenue/FTE but also a heavier payroll. The ratio only has meaning when combined with the loaded hourly cost (ratio #3) and the profitability rate per project (ratio #4). A high revenue/FTE with low margins indicates the firm is producing volume without generating profit.
Ratio #7 -- Effective Billing Rate
Definition
The effective billing rate measures the gap between what the firm could bill (billable hours valued at the contractual rate) and what it actually bills. It's the indicator of "lost revenue" -- income left on the table because of hours worked but never billed.
Formula
Effective billing rate = (Amount actually billed / Theoretically billable amount) x 100
The theoretically billable amount corresponds to hours actually spent on the project, valued at the contractual hourly rate or pro-rated to the phase fees.
Industry Benchmarks
| Level | Billing rate | Interpretation |
|---|---|---|
| Excellent | > 92 % | Rigorous management, few leaks |
| Adequate | 85 -- 92 % | Identifiable room for improvement |
| Concerning | 75 -- 85 % | Significant revenue loss |
| Critical | < 75 % | A quarter of the work goes unbilled |
Key figure: Most architecture firms have an effective billing rate between 75 and 85%. This means that 15 to 25% of work performed is never billed. On revenue of EUR 500,000, a billing rate of 80% represents a theoretical shortfall of EUR 125,000 per year.
Measurement Method
The effective billing rate requires crossing two data streams:
- Hours actually spent on each project (time tracking).
- Amounts actually billed per project and per phase (billing tracking).
The gap between the two reveals "leaks": extra hours absorbed without amendments, time spent on non-contractual modifications, phases that exceed their envelope without the surplus being re-billed.
Recommended frequency: Monthly per project, quarterly for the overall summary.
Pitfall to Avoid
Pitfall to avoid: Assuming that a signed lump sum means there's no need to track hours. It's exactly the opposite. The lump sum fixes the billable amount. If actual hours exceed the planned envelope, the difference is free work. Time tracking isn't for billing by the hour: it's for knowing how much free work the firm absorbs -- and for deciding whether that's acceptable or whether action is needed (amendment, scope adjustment, anticipation on upcoming phases).
The Principal's Dashboard: Summary of 7 Ratios
The table below brings together all 7 ratios in a single view. This is the vital minimum for managing an architecture firm with reliable data.
| # | Ratio | Formula | Optimal benchmark | Frequency |
|---|---|---|---|---|
| 1 | Utilization rate | Productive hours / Available hours x 100 | 75 -- 85 % | Weekly |
| 2 | Productive / non-productive ratio | Project hours / Total hours x 100 | 70 -- 80 % | Monthly |
| 3 | Average loaded hourly cost | (Salaries + charges + overhead) / Productive hours | EUR 42 -- 55/h | Semi-annual |
| 4 | Profitability per project | (Fees - Actual hour cost) / Fees x 100 | 15 -- 25 % | Per phase |
| 5 | Quote conversion rate | Signed projects / Quotes submitted x 100 | 25 -- 40 % | Quarterly |
| 6 | Revenue per employee | Annual revenue excl. tax / Number of FTEs | EUR 60 -- 90K | Annual |
| 7 | Effective billing rate | Amount billed / Billable amount x 100 | > 90 % | Monthly |
How These 7 Ratios Connect
These indicators don't work in silos. They form a coherent system whose input data is always the same: time spent.
- The utilization rate (ratio #1) and the productive ratio (ratio #2) determine the volume of productive hours, which is the denominator of the loaded hourly cost (ratio #3).
- The loaded hourly cost is the key to calculating project profitability (ratio #4) and the effective billing rate (ratio #7).
- The conversion rate (ratio #5) impacts the productive ratio, since unconverted commercial hours are non-productive hours.
- Revenue per employee (ratio #6) is the final outcome of the entire system: it reflects individual productivity, commercial pipeline quality, and billing efficiency.
Without reliable, structured, and regular time tracking, none of these ratios can be calculated accurately. That's why time tracking isn't just another administrative tool: it's the data foundation on which all firm management rests.
Getting Started: Where to Begin
If your firm doesn't yet track these ratios, don't try to implement everything simultaneously. A progressive approach is more realistic and sustainable:
- Months 1-2: Implement time tracking by project and by phase. This is the prerequisite for everything else. Without this data, no ratio is calculable.
- Month 3: Calculate the loaded hourly cost (ratio #3) from accounting data. This is a one-time calculation that doesn't require a specific tool.
- Months 4-6: Calculate ratios #1, #2, and #4 from accumulated time data. Three months of data is enough to identify reliable trends.
- From month 6: Integrate ratios #5, #6, and #7 and build the complete dashboard.
The time investment is modest -- a few minutes per day for entry, a few hours per month for analysis. The return is considerable: real visibility into the firm's performance, better-calibrated fees, and decisions based on data rather than intuition.
Key takeaway: A 7-ratio dashboard doesn't transform a firm overnight. But it makes visible what was invisible. And in a business where margins are decided by a few percentage points, this visibility makes the difference between a firm that reacts and a firm that leads.
Discover how a structured time tracking tool can automatically feed these ratios and simplify your firm's management on our features page.