We recently bought a detached home built in the 1990s with an attic conversion dating from the mid-’90s.
While there was an opinion of compliance on the conversion, when our structural engineer came to view the house in June 2025, he advised that prior to the attic conversion, the original truss roof had spanned from front to back, with all loads going to the front and the rear. When the conversion was carried out, it appears the load was now being borne by steel beams but with no new supports provided. He says this means that the loads are now going down into the stud partitions at first-floor level. They are obviously not designed to bear this weight.
Following our structural engineer’s visit, I asked a local builder who specialises in attic conversions to take a look at the works. He deemed them to be reasonable and said that our engineer may have been a little pedantic in his assessment. While I know that this was just one structural engineer’s opinion, I am inclined to take his guidance seriously. I am now worried, however, that if I pay another builder and engineer to fix the problem with our attic conversion, I will have no idea if it will be “right” or not.
Should I do something about this, and if I do, how can I be sure that the work has been carried out correctly?
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A surveyor I once worked with used to say in situations such as yours, “as doctors differ, patients die”. It’s probably a bit dramatic when talking about property rather than people – but the sentiment struck me again when I read your question.
You’ve received two opinions on your attic conversion that could not be more different – one from a structural engineer raising concerns about how the loads are now being carried, and another from a builder who feels the engineer is being overly pedantic. You’re left stuck in the middle, none the wiser, and understandably anxious about what, if anything, you should do next.
Attic conversions from the 1990s can sometimes be a law unto themselves. Many were built at a time when expectations and standards were much looser. Your engineer’s comments about the original truss roof sound about right: those prefabricated trusses were designed to span from front to back, transferring loads to the external walls.
Once people start removing sections of those trusses or inserting rooms into that space, the load paths change. In your case, steel beams appear to have been added, but without proper new supports beneath them, the loads are now being passed into stud partitions on the first floor – which were never designed to do that job.
That’s the technical explanation. The practical reality is slightly different. If this conversion was carried out 30 or more years ago and you’re not seeing sagging roof slopes, cracking ceilings, bouncing floors or any obvious signs of structural distress, then the conversion is at least “functioning” in a real-world sense.
Structures that are fundamentally deficient usually tell on themselves long before this point. An attic conversion that is decades old and still holding its shape is very often a sign that, while it may not meet modern or expected standards, it hasn’t failed either.
If the attic does need upgrading, insist on proper drawings and calculations. One of the biggest problems with retrofitted attic works is not the workmanship but the lack of a clear design from the outset
This, I think, is why your builder has shrugged it off, and why your engineer has not. Both opinions can be true at the same time. An older conversion can function reasonably well, while still technically relying on supports that were never designed for the loads they are now carrying.
The real question you are asking is twofold: should you intervene at all, and if you do, how do you make sure it’s done properly?
The first part depends on what you’re seeing day-to-day. Walk through the attic and trust your senses. Do the floors feel uneven? Are the ridge and planes of the roof straight and level when viewed from outside? Are there cracks on the ceilings or walls below at the first floor? Is anything creaking, sloping or moving? If you’re not seeing any of these issues, then the conversion may well be performing adequately in practice.
You don’t have to rush into expensive remedial work just because one professional has raised concerns. You simply need to establish whether the “patient”, to borrow that earlier phrase, is actually displaying any symptoms.
If you are concerned – or if you simply want the comfort of knowing that everything is structurally sound – then the safest route is to have an independent structural engineer (ideally one who specialises in attic conversions and trussed roofs) carry out a focused review. Let that person look at how the loads are being carried, whether the steel beams have adequate bearing, and what interventions might be needed to bring the structure up to an acceptable, modern standard.
This does not commit you to doing the work; it simply clarifies what, if anything, needs to be done. However, the engineer may require some opening-up works on the stud partitions or other areas to see the quality of these structures as part of their assessment.
If the attic does need upgrading, insist on proper drawings and calculations. One of the biggest problems with retrofitted attic works is not the workmanship but the lack of a clear design from the outset. When you have proper structural drawings, a competent builder can follow them, and you can be confident that the work has actually resolved the issue rather than created new ones.
Good documentation also protects you whenever you eventually sell the property. Make sure all works take account of insulation standards and ventilation paths – these are commonly neglected in attic conversions.
It’s worth saying that attic conversions from this era can sometimes fall into the grey zone: not perfect, not compliant with modern standards, but still functioning. Your aim is simply to work out whether yours falls on the safe side of that line.
A calm, evidence-based approach will serve you far better than rushing into works or worrying unnecessarily. And remember, differing opinions are normal. What matters is understanding the building in front of you and making informed decisions about its future.
Aidan McDonald is a chartered building surveyor and a member of the Society of Chartered Surveyors Ireland
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