The honest answer to what a Passivhaus consultant costs is that it depends, and any firm that quotes a single day rate before understanding your project is guessing. That is not evasion. Consultancy fees swing by an order of magnitude depending on what you actually need, and the useful question is not what is the rate but what is the scope. This piece sets out what drives the cost, how sensible fees are structured, and how to tell whether you are getting value or paying for a logo.
Fees follow scope, not hours
Passivhaus consultancy covers a wide span of work, and the fee tracks where on that span your project sits.
At the light end is an early feasibility model: a single PHPP run at concept stage that tells a client whether the standard is realistic on their site and what it would take to reach it. That is a contained piece of work with a contained fee, and it is often the best money a client spends, because it de-risks the biggest decision before the design commits.
At the heavy end is full technical delivery: the consultant models the building through every design stage, resolves the thermal bridges, writes the airtightness strategy, supports the team through construction, and shepherds the evidence to the certifier. That is a running engagement over the life of the project, priced accordingly.
Most projects sit somewhere between the two, and the fee is a function of where. Asking for a rate without pinning down the scope is like asking what a building costs per square metre with no brief.
What actually drives the number
Four things move a Passivhaus consultancy fee more than anything else.
Scale and repetition. A single dwelling and a scheme of three hundred are not linearly different. The scheme has more at stake in every assumption, more house types to model, and more coordination, but it also spreads the specialist effort across many units. Cost per home falls with scale even as the total rises.
Complexity. A compact, well oriented new build is straightforward for the model. A constrained urban site, an awkward form factor, a heritage or EnerPHit retrofit with existing fabric to work around, all demand more modelling and more problem solving, and cost more.
How early you engage. This one is counter-intuitive: engaging a consultant sooner usually lowers the total fee, not raises it. Early modelling steers decisions while they are still cheap to change on paper. Late modelling documents decisions that are already expensive to unwind, and spends fees firefighting problems that early work would have prevented.
Whether certification is in scope. Advisory modelling and full support through independent certification are different commitments. Certification carries its own separate cost, which we cover in how much Passivhaus certification costs, and it is worth keeping the two lines distinct when you compare quotes.
How good fees are structured
Because the work spans stages, the cleanest fee structures follow the stages rather than an open ended clock. Three patterns are common and all are reasonable.
A fixed fee for a defined deliverable, most often the early feasibility model, where the scope is clear and a client wants certainty before committing further. A stage based fee tied to design stages, which suits full delivery and lets both sides see the commitment building as the project does. And a day rate for genuinely open ended advisory support, which is fair for ad hoc input but a poor way to price a large defined piece of work, because it prices your effort and hides your scope.
What you want to avoid is a number with no scope attached. A low day rate on a vaguely defined engagement routinely costs more than a higher fixed fee on a tightly defined one.
Judging value, not price
A Passivhaus consultancy fee is small next to the cost of the building it governs, and its job is to protect a far larger number: the build cost, and the fifty year running cost of getting the physics wrong. We put the build side of that in what it costs to build a Passivhaus in Ireland, and the consultancy fee should be read against it, not in isolation.
The value test is straightforward. Does the consultant catch the assumptions that would otherwise fail at certification. Do they steer design decisions early, when they are cheap, rather than document them late, when they are not. Do they hand you a model you can trust and a certifier who signs it without a fight. A cheap consultant who lets a default thermal bridge value ride to completion is not cheap. They are the most expensive line in the project, paid later. We wrote about what a PHPP consultant actually does precisely because the value lives in that work, not in the rate.
Where Mosart fits
We price Passivhaus consultancy against scope, and the first conversation is usually free: what the project is, what stage it is at, and what it genuinely needs, which is often less at feasibility and more at delivery than clients expect. From there the fee is defined against real work, not a rate card. If you want a number for your specific project, the fastest route is to tell us about it through the consulting practice, and we will scope it honestly, including telling you when you need less than you asked for.