When the Building Safety Act 2022's golden thread documentation requirements bedded in through 2024 and 2025, structural engineering practices across the UK found themselves writing more than ever — not doing more engineering, just documenting it more. Fortis Structural Engineers, a five-person practice in Derby, was losing 28 hours every week to structural report writing, Building Regulations correspondence, and fee proposal preparation. Three AI agents changed the maths. Twelve weeks after go-live: 62% more projects delivered, 23 hours recovered weekly, £75 a month to run.
Why Structural Engineers Are Drowning in Documentation
The Building Safety Act 2022 changed the compliance landscape for structural engineers working on higher-risk buildings. But the ripple effects went wider than just HRBs. The cultural shift towards more thorough documentation — golden thread evidence, structured design reports, clearer load path narratives — has touched nearly every project type. Engineers who were previously writing a two-page structural appraisal now write five pages covering the same ground, but in a format that satisfies both the architect and the building control officer.
A structural engineer designing a residential extension or commercial fit-out generates roughly the same technical calculations they always did. What has changed is the written output that now accompanies them: structural design reports, engineers' certificates, defect appraisals, load path summaries, and inspection reports — all formatted to professional standards and cross-referenced against current BS standards and Eurocodes. The keyboard time has grown faster than the site time.
UK construction and design professionals were already feeling the shift before the regulatory changes compounded it. A 2026 survey found that 46% of UK construction professionals now use AI tools, saving an average of three hours per week per person — but most of those savings come from individual tool use rather than integrated systems. The practitioners seeing the biggest returns are the ones who have moved from ad-hoc AI use to structured agent workflows.
Add to this the competitive pressure on fee proposals. A Derby structural engineering practice competes for residential, commercial, and industrial work across the East Midlands. Getting a fee proposal in front of a prospective client quickly — same afternoon rather than next morning — is increasingly decisive. Structural engineers who take 24 hours to respond to a request for a fee proposal lose some of that work to practices who respond in two hours.
Fortis Structural Engineers, founded in 2019 by Kieran Holloway, had grown to five engineers by early 2026. By February 2026, the pattern was clear: the team was completing roughly 16 projects per month but Kieran estimated they could manage 24 to 26 at their current technical capacity if the admin overhead were removed. The bottleneck was not engineering skill. It was report writing, correspondence, and proposal preparation — three tasks that followed a recognisable pattern on every project but still consumed a disproportionate share of every engineer's week.
The calculations take an hour. Writing up the report explaining those calculations — with the right language for building control, the right caveats, the right structural narrative — takes another two hours. And you do that for every project, every time, in the same basic structure. The AI does not do the calculations. But it turns the report into a 20-minute task instead of two hours. That is where the capacity came from.
— Kieran Holloway, founder, Fortis Structural Engineers
The Three Agents We Built
After a discovery session and workflow audit with Kieran's team, three areas stood out as the primary time drains: structural report drafting, Building Regulations correspondence, and fee proposal writing. Together they accounted for the 28 hours per week the team wanted back.
Agent 1: The Report Drafting Agent. Structural reports at Fortis follow a consistent structure: project overview, scope of inspection, structural description, findings, recommendations, conclusions, and limitations. The technical content varies by project; the format does not. The Report Drafting Agent takes the engineer's site notes, calculation summaries, and marked-up sketch details and generates a full draft report in Fortis's standard format. The engineer reviews the draft — typically a 20-minute check — corrects any technical nuances, and approves. What previously took 90 to 110 minutes now takes 20. The agent was trained on five years of Fortis's completed reports, so the structural narrative language, standard caveats, and limitation clauses match Kieran's house style precisely.
Agent 2: The Building Regs Correspondence Agent. A typical project generates between three and eight written exchanges with building control: initial notices, responses to technical queries about load paths or foundation depths, clarifications on structural connections, and final sign-off correspondence. These follow predictable structures but require technical accuracy and professional tone. The Building Regs Correspondence Agent drafts responses to BCO queries using the project file as context — drawings, calculations, and prior correspondence — and flags anything requiring specific engineering judgement before dispatch. The team reviews each response in 10 to 15 minutes rather than the previous 45 to 60, then sends. This single change recovered eight hours per week across the team.
Agent 3: The Fee Proposal Agent. Fee proposals at Fortis had no consistent format, took 45 to 90 minutes to draft, and were sometimes delayed by a day when engineers were on site. The Fee Proposal Agent generates a structured proposal from a short project brief — scope, location, building type, approximate area, construction method — cross-referenced against Fortis's fee schedule and similar past projects. Kieran adjusts the fee figure where judgement is needed, but the scope description, programme, professional indemnity note, and terms sections are generated in under three minutes. Proposals now leave the office the same afternoon an enquiry arrives.
Total build time: seven working days. The system runs on n8n for workflow orchestration, connects to Fortis's project management software via API, and uses Claude for all report drafting, correspondence, and proposal generation. Monthly running cost: £75.
Month One: The First Signs of Change
The first month running all three agents produced results the team could see immediately in their completion rate, but it took a few weeks to trust the numbers.
Report drafting time dropped from an average of 100 minutes per report to 20 minutes — the time for an engineer to read through and refine the draft. Building Regs correspondence time fell by 76%. Fee proposals, which had previously gone out the following day in 38% of cases, now went out the same afternoon 92% of the time. The recovered hours moved back into active projects straight away.
In month one, Fortis completed 20 projects — up from the previous monthly average of 16. Four additional projects in the first month with no new hires. The same-day fee proposal turnaround contributed to three new project wins in the first fortnight — enquiries Kieran believed would have gone to a competitor had the response arrived 24 hours later.
Twelve Weeks Later: What the Practice Looks Like Now
We reviewed the data with Kieran twelve weeks after go-live in early July 2026.
- Monthly project completions: 16 → 26 (a 62% increase)
- Weekly admin hours across the team: 28 → 5
- Monthly running cost of the AI system: £75
- Team size: 5 (unchanged)
- Same-day fee proposal dispatch rate: 92% (up from 62%)
- Average structural report review time per engineer: 20 minutes (down from 100 minutes)
- BCO query response time: Same week in 94% of cases (previously 58%)
- Client satisfaction score (post-project survey): 4.8/5 (up from 4.3/5)
The client satisfaction improvement is worth dwelling on. Architects and project managers notice when their structural engineer returns reports in 48 hours instead of five working days. Three of Fortis's top five architectural referral partners specifically mentioned responsiveness in their survey responses. That responsiveness is now built into the system rather than depending on whether Kieran had a quiet week. It is consistent because it is structural.
The BCO query response time change has a less obvious value that compound over time. When building control officers receive clear, well-referenced responses within the week, projects move faster. Fewer queries stall. Fewer extensions of time are requested. The smooth project rhythm reinforces Fortis's reputation with both clients and the BCOs they work with repeatedly.
We are the same five people. We have not changed what we do — the calculations, the site visits, the engineering judgement. What we have changed is everything around it. The reports go out faster. The proposals go out the same day. Building control gets a response this week, not next week. And we are taking on more work because we have the hours to do it.
— Kieran Holloway, founder, Fortis Structural Engineers
What Three Agents Cost vs What They Return
The economics are straightforward. Fortis's blended average project fee across residential and commercial work is approximately £1,500. The ten additional monthly completions by week twelve represent roughly £15,000 in additional monthly revenue. Against a running cost of £75 per month, the return on the infrastructure investment is around 200x. The build cost paid back inside four weeks.
The less visible return is positioning. Structural engineers who respond to enquiries the same afternoon and return reports within two days are more likely to be included in framework agreements with architectural practices and main contractors. Two new framework relationships Fortis established in the first three months came directly from the responsiveness improvement — both cited turnaround time as the deciding factor. That pipeline value will compound for years.
There is also a quality dimension worth naming. Structural reports produced under time pressure — when an engineer is rushing through a backlog before a deadline — carry a higher risk of inconsistencies than reports produced with proper review time. The Report Drafting Agent creates a consistent first draft that a fresh pair of eyes reviews methodically, rather than a rushed draft composed at the end of a long day. Fortis's technical revision rate, tracked internally through BCO query volume on closed projects, dropped by 58% in the first twelve weeks. Fewer revisions means faster project closures and lower professional indemnity risk exposure.
For UK structural engineering and civil engineering practices carrying a similar documentation overhead — and most of the five-to-fifteen-person firms we work with are — the build sequence follows the same logic as every other professional services AI operating system: identify the three highest-friction workflows, automate the structured parts, keep human judgement on the technical parts, and measure the recovered hours in the first four weeks.
The AI capability stack post explains the sequencing logic for which agents to build first. The AI ROI framework gives the four-metric model we apply across practices of this size. And the compounding advantage post explains why Fortis's numbers will look considerably different again in twelve months — the intelligence loop that improves every report draft as more projects pass through the system is only just beginning.
If your structural, civil, or building engineering practice is losing significant hours each week to report writing, BCO correspondence, or proposal preparation, book a free 30-minute call. We will map your three highest-friction workflows, model what a Fortis-style build would recover for your team size, and show you exactly what the first twelve weeks would look like. The call is free. The capacity you recover is not.