When to hire a building inspector (and what their report needs to contain)
An inspector is the only professional opinion on your house that does not get more expensive if the answer is 'do the work.' Their report becomes the brief the contractor bids against, which changes the comparison from 'whose proposal do I prefer' to 'who delivers this scope best.'
The advice everyone gives is to get three quotes. What that gives you is three contractors competing to do the work; none of them are paid to tell you whether the work needs doing in the first place. That is the gap an inspector fills. An inspector is paid to look at your house and write a report, and they will not do the repair work themselves. The fee is for the inspection and the report; the answer the report contains does not change what the inspector earns. They are the only professional opinion in the residential maintenance chain whose income is not downstream of the recommended scope.
Why the asymmetry matters
A contractor’s quote is also their proposal for how much work to do. Nothing dishonest about this; it is how contracting works. A contractor who has come to your house to give you a quote already has half a foot in the door for the assignment, and they will tend to recommend the work they are best equipped to do, at the scope they are best set up to bid. The first opinion you get from a contractor is downstream of “what would I do here,” not upstream of “does anything need doing.”
An inspector specifies a minimum scope based on a holistic look at the building. The contractor can then bid that scope, refine it, or push back on it, but the starting point is set by someone who is not bidding for the job. That changes the comparison from “whose proposal do I prefer” to “who delivers this scope best.” The question gets simpler, because the scope is now a constant across the three quotes instead of a variable.
The inspector also looks at things a single contractor would not have reason to flag. The classic example: a less-noble metal placed above a more-noble metal somewhere on the roof or facade, silently encouraging galvanic corrosion in the lower one. A roofer called to look at the upper part would not mention the lower; the lower contractor does not know what is above it. An inspector sees the building, not the component they were called for.
When the inspector pays for itself
Three moments, each with a different brief.
General maintenance planning, every ~5 years. Not for routine work like a boiler service; you call a contractor for that and they do both the inspection and the work in the same visit. The general inspection is for everything out of sight or beyond your knowledge: the roof, the facade, the structural elements, the parts of the building you cannot reach yourself. The output is the document you would need to move from reactive maintenance into planned, which is the shift that produces the cost difference between the two modes (see Corrective vs planned maintenance).
Pre-job scope-setting, before any major contract. If a contractor has told you the roof needs replacing, the facade needs repointing, or the foundation needs work, an inspection first is the cheapest way to find out whether the proposed scope matches what the building needs. The inspector can specify “20% of roof tiles in the upper south slope, refit ridge cap” rather than the contractor’s “let’s do the whole roof.” Two different scopes, two different prices. The inspector’s specification then becomes the brief you put in front of the next three contractors (see How to brief your contractor).
Post-job sign-off, while the scaffolding is still up. Negotiate this into the contract before signing: the inspector returns at the end of the job and signs off on what has been done. They come back while access is still cheap, look at the work in the contractor’s language with the tools to verify it, and either sign off or list the items that need correcting. If anything is sloppy, the contractor fixes it before the scaffolding comes down. Without this clause, sloppy work is your problem to discover, document, and litigate after the contractor has been paid and the access is gone.
What the report needs to contain
Three things at minimum, in the Dutch professional inspectors’ shorthand: locatie, oorzaak, oplossing. Location, cause, solution. For each defect the inspector identifies, the report names where it is, what is causing it, and what should be done about it. Without the cause, the contractor fixes the symptom and the defect comes back. Without the solution, the contractor proposes their own and you are back to a single-source opinion.
Four things worth asking for in addition:
- A risk assessment that names what happens if you do nothing. This is the part contractors do not write because it does not generate work. It is also the part you need to make the trade-off in a year you cannot afford the repair.
- A ballpark cost for each remediation. Inspectors give ranges; they do not price the way contractors price. The range is enough to plan against.
- A validity period for the assessment. A 2024 report is not a current view of the building in 2027.
- Identification of safety gaps any contractor will need to budget for. The classic example is missing roof anchor points; if the roof has none, every future roof contractor needs to install temporary or permanent fall protection, and that cost should be on the page rather than appearing as an extra later.
Two things to insist on. First, the same template each time: if your last report was structured as 12 components with photos in a particular order, the next inspector should use the same shape, so year-over-year comparison is a glance rather than a kitchen-table cross-reference exercise. Second, the inspector physically goes on the roof, into the loft, behind the cladding. An inspector who stays on the ground with an iPad is selling photos of your house, not a report on it.
One thing to refuse. The 500-page report with every conceivable component listed and disclaimers in every section is defensive volume, not useful information. You will not re-open it. The right report is concise enough to read in one sitting and structured enough to compare against next time.
Worked example: Pieter in Utrecht
Pieter has a 1970s detached house. After a winter storm, three roof tiles slip and one ends up in the gutter. He calls a roofer for a quote. The roofer comes out, climbs up, takes a look, and says: “Honestly the whole roof is past it; we should do a full reroof. EUR 18,500 for materials and labour, six days of work.”
Pieter pauses and books a building inspector instead. Cost: EUR 450 for the visit and the report.
The inspector goes on the roof properly, takes four hours, and produces a report four days later. Locatie: ridge cap and the upper third of the south slope, ~20% of total roof area. Oorzaak: the original ridge mortar has degraded, and the tiles in that area have lost their grip over the last five winters; the underlay across the rest of the roof is sound. Oplossing: refit the ridge cap with mechanical fixings, replace 20% of tiles in the affected area, leave the remaining 80%, which still have an estimated 12 to 15 years of useful life. Risk: further movement in the next two winters is likely if not addressed; a single dropped ridge tile in a high-traffic area is a safety risk. Cost ballpark: EUR 4,800 to EUR 6,400 for the work, plus safety. Note: the roof has no permanent anchor points; any contractor needs to install temporary fall protection (~EUR 600 to 900) or you can budget EUR 1,200 to 1,800 for permanent anchor points, which the next contractor on this roof will benefit from too.
Pieter takes the report to three roofers. Quotes come back at EUR 5,200, EUR 5,800, and EUR 6,400 for the partial replacement plus temporary safety. He picks the middle one. The mandate includes a clause: the inspector returns to sign off the work before final payment.
Inspector returns at completion, EUR 500. Finds two issues: three tiles laid the wrong way round, ridge mortar applied too thinly in one section. Contractor fixes both within the agreed price. Scaffolding comes down. Work is signed off.
Total spend: EUR 450 (inspection) + EUR 5,800 (work) + EUR 500 (sign-off) = EUR 6,750. Original full-reroof quote: EUR 18,500. Difference: EUR 11,750. The remaining 80% of the roof is now scheduled in Pieter’s plan for replacement around 2038 to 2042, which is the lifecycle question the inspector’s report turned into a date.
The honest counter-case: if the inspector had concluded the full reroof was justified, the EUR 450 would have bought certainty rather than savings. Either outcome is useful. The expensive case is the one where the homeowner accepts the first contractor’s scope without an independent view of whether it matches what the building needs.
What the inspector’s report changes for the contractor
A contractor reading an inspection report knows the homeowner has done the work: the brief is precise, the scope is fixed, and the risk assessment names what they are being asked to address and what they are not. There is less ambiguity to absorb into the price as a cushion, and less surface area for scope creep mid-job.
This shifts the pricing dynamic. A contractor pricing against an inspector’s specification competes on execution, not on diagnosis. Three contractors bidding against the same scope produce three quotes that are comparable, which is the thing “get three quotes” is supposed to deliver but rarely does in practice (see Comparing contractor quotes). The inspector’s report is what turns the comparison from intentions to commitments.
The inspector approval clause changes the dynamic on the other end of the job too. A contractor who knows the work will be signed off by an independent professional has every incentive to do the work properly the first time, because rework before the scaffolding comes down is cheaper for them than rework after.
Where to start
The shortest version of the rule: book an inspector before the next major contract, not after. For everything else:
- Routine planning, every ~5 years: book a general inspection. Brief the inspector to use the same template as last time. The first establishes the baseline; the next tells you what has changed.
- Before any major job: the inspector visit comes first. Their report becomes the brief you put in front of three contractors.
- Before signing any major contract: write the inspector approval clause into the work specification. The sign-off triggers final payment, not yours.
- When choosing an inspector: confirm they go on the roof physically, and that they can produce a report in locatie / oorzaak / oplossing form with risk, cost ballpark, and validity period. Refuse the 500-page version.
Related guides
- How to brief your contractor: the inspector’s report becomes the brief.
- Comparing contractor quotes: three quotes are only comparable when the scope is fixed.
- How contractors think: why the contractor’s first opinion is downstream of “what would I do here.”
- Corrective vs planned maintenance: the inspector’s report is the document that makes the shift from one to the other possible.
- How to set a mandate: where the inspector approval clause goes.
Glossary terms used in this guide
- Glossary: Inspector: the professional opinion with no skin in the repair.
- Glossary: Mandate: the signed instruction that includes the inspector approval clause.
- Glossary: Component: the unit the inspector’s report is structured around.
- Glossary: Planned maintenance: the maintenance mode the inspector’s report enables.
- Glossary: Lifecycle maintenance: what the inspector’s lifespan estimates feed into.
Where AppKeep fits
The inspector’s report is a document that needs to live somewhere it can be re-opened, compared, and referenced. Most pre-purchase inspection reports get filed once and never read again, which is the structural reason their value mostly evaporates within a year of issue.
AppKeep keeps the report alive. Each defect the inspector identifies becomes a component in the picture; cost ballparks feed the multi-year plan; remediations get dates. The next inspection, ~5 years later, is briefed against the existing template, so the comparison is a glance rather than a reconstruction. The reports compound rather than expire.