Multi-disciplinary practice PI insurance

Reviewed by Matthew Bartlett, Director · Last reviewed 2026-06-23

Multi-disciplinary practices (MDPs) combine two or more regulated professions in a single trading entity — typically architecture + engineering + surveying + project management. The PI position is more complex than for single-discipline firms because each profession has different regulatory requirements, claims patterns, and underwriting appetite. This entry sets out the practical position in 2026.

What counts as a multi-disciplinary practice

For PI purposes, an MDP is any firm where the same trading entity provides services that would normally be regulated by two or more profession-specific bodies (ARB, RICS, ICAEW, etc.) OR which holds professional registrations in more than one discipline.

Examples:

• Architects + civil engineers in the same partnership
• Surveyors + project managers + cost consultants
• Engineering + environmental consultancy + ecology
• Architects + interior design + planning consultancy

The regulatory layered question

Each profession in the MDP may have its own PI minimum. For ARB-registered architects, ARB's minimums apply. For RICS-registered staff, RICS's banded scheme applies. The PI policy needs to satisfy ALL the applicable minimums simultaneously.

In practice: cover the MDP at the highest applicable single minimum. If RICS banded requirements yield £1m for the firm's fee band, ARB requires £250k minimum, and the firm has contracts requiring £5m, then £5m is the floor.

Underwriting MDPs

Insurers price MDPs by service mix:

• Architecture-led MDP rates broadly like architecture, with a small uplift for combined exposure
• Engineering-led MDP rates like engineering (often slightly more than architecture)
• Surveying-led MDP rates like surveying
• Mixed-cover MDPs (no dominant discipline) rate as a weighted average, often with an uplift for complexity

The proposal form typically asks for fee split by discipline. Be honest in the split — under-stating one discipline to get a lower rate is non-disclosure.

Wording considerations

• Professional business definition. The schedule must list every discipline performed. If "surveying" isn't listed and a survey claim arises, the policy may not respond.
• Cross-discipline claims. A claim involving multiple disciplines (e.g. a coordinated architecture+engineering+M&E defect) is one claim under the PI policy, even if multiple disciplines contributed.
• Sub-disciplines. Some sub-disciplines have specific underwriting (e.g. principal designer under CDM, fire engineer, BNG assessor). Check whether they're explicitly named.
• Subcontractors and associates. Many MDPs subcontract specialist work. Cover should extend to subcontractors directed by the MDP, with the work being part of the MDP's engagement.

Aggregation across disciplines

A single project failure may give rise to multiple claims — one from the client for design failure, one from the contractor for delay, one from the subsequent owner. The aggregation clause determines whether these are one claim (one limit) or many (each gets its own limit).

Standard PI wording aggregates by "originating cause". If a single design error caused all the claims, they aggregate into one. If multiple separate errors caused different claims, each is separate.

For MDPs, aggregation often favours the policyholder when multiple parties claim from the same project failure (one limit applies, not many). It works against the policyholder when one project produces several claim limits' worth of loss.

Run-off and partner exits

When a discipline-specific partner leaves an MDP:

• Their work to date is covered by the MDP's policy at the time they did it (subject to claims-made trigger)
• Going forward, the MDP's policy continues to apply to their old work via retroactive cover
• If the departing partner sets up their own practice, that new practice needs its own PI; it does NOT inherit the MDP's policy
• If the MDP dissolves entirely, run-off is needed for all the disciplines that were practised

Typical structure for a 10–50-person MDP

• Limit of indemnity £5m – £15m (driven by contract requirements)
• Stacked primary + excess if exceeding single-insurer capacity
• Defence costs in addition
• Each-and-every-claim basis where possible
• Subcontractor extension
• Worldwide jurisdiction excluding US/Canada
• Cyber as a separate policy
• Public liability + employer's liability + office combined

Annual PI premium typically £6,000 – £40,000 depending on size, discipline mix, and contract type (HRB/cladding work elevates significantly).

The MDP discount question

Some insurers offer modest discounts for MDPs on the theory that the combined disciplines see each other's work and catch errors before they crystallise. The evidence for this is mixed and the discount is usually small (5–10%). Don't expect a structural pricing benefit just because the firm is multi-disciplinary.

About Apex Insurance Brokers

Apex Insurance Brokers Limited places PI cover for UK multi-disciplinary practices including architecture + engineering + surveying + project management combinations. FCA firm reference number 724952. We market to insurers who write MDP risks specifically rather than treating them as single-discipline categories.