It's a fair question, and one almost nobody in this line of work answers straight: most sites talk about a "bespoke quote" and steer you to a call. I'd rather do the opposite — set out a clear, published framework you can size up before you ever speak to me. Here's how the cost of representation actually works, and why how you're charged matters every bit as much as the figure.
Two ways to charge — and why they're not the same
Plenty of owner's representatives bill a percentage of the works — often somewhere between five and ten per cent in the professional market. It looks tidy, but there's a flaw built in: the more the project costs, the more your adviser makes. Your adviser's interest and yours pull apart at precisely the point where they ought to line up.
I do the reverse: a fixed fee per phase, agreed up front and untied to the cost of the build. Whether the project grows or shrinks, my fee doesn't move on that account. My only stake stays the same as yours — that the project be right, not that it be expensive.
How the fee is worked out: a base, then the square metre
What it costs comes down to two things: the size of the property and the phases you hand me. Rather than one daunting number dropped on you all at once, my schedule starts from a base fee covering the first 90 m², with a per-square-metre top-up beyond that — the reasoning being that a large flat takes more reading, more visits and more pages of reporting than a small one. The phases are priced separately.
Paying stage by stage, for what you actually need
Representation breaks into phases that follow the project's own timeline, and you only sign up for the ones you want:
- Before you buy — the patrimonial read: an independent read of the property and its paperwork before you sign anything. Many clients start here, and some stop here, if the read comes back "walk away".
- Scoping — pinning down the brief, a realistic budget, and getting the consultation of the trades and the design authority ready.
- On site — the long stretch: regular visits, the weekly site journal, written warnings, your decisions teed up, month after month.
- Closing the works — the pre-handover summary that gets you ready to sign the official certificate with your design authority.
Splitting it this way does away with the single scary number and leaves you in charge of the scope.
What the price never includes: a commission
Whatever the figure, one thing holds: I take no commission, rebate or kickback from any architect, contractor, broker or supplier on your project. My fee comes from you, and from you alone. That's what makes my fee my only income on your file — and so makes my warnings worth listening to.
The exact figures, phase by phase, are on the Fees page — the only up-to-date source. For why the no-commission rule matters so much, see "independence and commissions". And to place my role next to your architect's, read "who does what on your renovation".
— Paris, May 2026. Charles-Eric Guerrier.