RPO vs in-house recruiting vs agency recruiters: which is right for your business?
A direct comparison of RPO/embedded recruitment, in-house talent teams, and traditional agencies for built environment and design and construction firms.
There's no universally best model — the right choice depends on hiring volume, urgency, and how much long-term capability you want to build internally. In short: agencies suit occasional, low-volume hiring where speed on a single role matters more than cost.In-house teams suit steady, predictable volume where cultural fit and long-term investment justify fixed headcount. RPO, including embedded models, suits businesses with high, bursty, or specialised hiring needs where dedicatedcapacity is required without the risk of building or cutting an internal team.
Comparison at a glance
Factor
In-house team
Agency (contingency)
RPO / embedded
Cost model
Fixed salary + overhead, regardless of hiring volume
Fee per hire, typically 15-25% of first-year salary
Retainer or subscription tied to defined scope, not per-hire fee
Speed to scale up
Slow — hiring your hiring team takes months
Fast per role, but no dedicated capacity
Fast — dedicated capacity flexes within days
Speed to scale down
Slow and costly — redundancy process
Immediate — simply stop instructing
Fast — scope adjusts on notice, no redundancy cost
Passive candidate access
Limited to team's own network and time
Varies by agency relationships
Built into the model — dedicated sourcing time
Best suited to
Steady, predictable volume, long-term culture investment
Occasional, low-volume, or urgent single hires
High, bursty, or specialised volume without headcount risk
Cost model: fixed headcount vs per-hire fee vs scoped retainer
An in-house team is a fixed cost regardless of how much or little you're hiring in a given quarter — you're paying for capacity whether it's fully used or not. Agencies invert this: no cost until a hire is made, but the fee, typically 15-25% of first-year salary, is paid per role with no economies of scale across volume. RPO and embeddedmodels are scoped to a defined level of delivery — a set number of roles, a set team size, or a fixed project — which tends to produce a lower and morepredictable cost per hire once volume rises past a certain point.
Speed: filling one role vs scaling a function
Agencies can move quickly on a single urgent role, since it's their core activity and often their only active priority for that client. Where they struggle is scale — instructing three agencies to hire ten people at once doesn't produce dedicated capacity, just three parallel, uncoordinated searches. In-house teams struggle in the other direction: hiring the hiring team takes months, so a sudden spike in demand outpaces the team's capacity long before new headcount is approved and onboarded. RPO is built for exactly this gap — dedicated delivery capacity that flexes up or down within days, not hiring cycles.
Control and quality
In-house teams have the deepest cultural and stakeholder context, which shows up in candidate fit and offer conversion. Agencies vary considerably — quality depends entirely on the individual consultant and how many other clients they're juggling for the same candidate pool. A well-run RPO or embedded model sits closer to in-house on quality, because the team works your systems, your criteria, and your employer brand directly, while still bringing dedicated sourcing capacity an internalteam often lacks the time to build.
The hybrid most built environment firms land on
In practice, few firms use only one model. A common pattern: an in-house team or lean talent function handles strategic, senior, and culturally sensitive hires; RPO or embedded support absorbs volume, project spikes, and specialised searches; agencies are used sparingly for one-off urgent roles outside the core scope. The mix shifts through the year as hiring volume moves — the model should flex with it, not the other way around.
FAQ
Is RPO cheaper than using a recruitment agency?
Usually, once volume rises above roughly 10-15 hires a year. Below that, occasional agency use is often more cost-effective than a retained RPO scope built for volume you're not generating.
Can RPO replace an in-house team entirely?
It can, but most firms get better results treating RPO as additional dedicated capacity alongside a lean in-house function that owns strategic and senior hiring decisions.
What's the biggest risk of relying only on agencies?
No dedicated capacity or continuity — each search starts from scratch, and quality depends entirely on which consultant picks up the brief that week.
What's the biggest risk of an in-house-only team?
Inability to flex quickly. A hiring spike outpaces internal capacity long before new headcount can be approved, hired, and onboarded — by which point the spike may have passed.
Written by George Dobbins, Founder of Arcavia Consulting — talent intelligence for the built environment.
Last updated: 14 July 2026