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Information Identification of BISF? Model

We've just had an offer accepted on a house on silbury road, I believe the construction is BISF and possibly A or A1, would anyone be able to advise. Attached is the house and one from the road that doesn't appear to have been updated or cladded unlike the one we've gone for. Just checking before starting the survey and conveyance process.

cheers in advance

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Topic starter Posted : 4:37 pm
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Hi Reuben, the property is a standard BISF A1 type construction.

The type A was the name given to 2 of the first prototype houses that were built in Edward Rd Northolt.

For more information, take a look at this post HERE

Good luck with your purchase.

Posted : 11:50 pm

@nsh-team Thanks. We've run into a little problem that we probably need to put elsewhere on the forum.

On inspection a structural surveyor suggested opening up one corner of the building, having the steel column delaminated back to bright metal and a rust inhibitor applied. Any idea how much this could cost, ball park at least?

Topic starter Posted : 8:29 pm


It's quite normal for a surveyor to request an invasive inspection of the stanchions, although not all request delamination. Invasive is the key word here, because whichever way it is conducted, it will require the removal of a portion of your external wall, which will need to be made good again, on top of the inspection and delamination costs.

The process itself if undertaken externally, can be quite expensive, as your external facade, be it render or insulated EWI, would need to be cut away, and ultimately repaired and replaced to match the existing surface, which is easier said than done in most cases.

I presume that the most likely corner stanchion in your case would be at the rear of the property, as you have a flank wall located at the front. Most surveyors want to inspect the stanchion base, as this is where interstitial condensation is more likely to occur.

It would be beneficial if the surveyor would agree to an internal access inspection, as opposed to an external. 

Stanchions can be inspected internally by removing a section or two of drywall, usually in the corner, near to the floor, in one of the outer facing corners of the house.

An internal inspection would be much cheaper as only drywall and wall coverings would need to be replaced, however much depends upon the level of access required to the stanchion itself, and in particular, the stanchion base/ floor plate. A section of the corner drywall studwork may also need to be removed, but this is easily replaceable. The only issue you may face internally, relates to the degree of access provided the base plate itself. Some stanchions are bolted onto concrete just below the screed level, whilst others may be also located several inches deeper down causing them to be virtually inaccessible to anything other than through invasive external access.

I think it would be good to ask if an internally accessed inspection would be acceptable and perhaps more importantly, to clarify if the stanchion base itself requires exposure, and to what degree.

In the event that external inspection is the only route, I would strongly suggest speaking to our good friend Alex Meagre at Structural Repairs Ltd on 023 8166 1411 to discuss the situation as this is most definitely his area of expertise.

Let me know your thoughts or if you need me to clarify anything as I'm not to well at moment and not quite as sharp as normal.

I've also added an image bel0w of an exposed corner stanchion from an internal point of view, however you wouldn't need to remove anywhere near this amount of drywall.

Also, take a look at the stanchion repair gallery HERE, as this will give you an idea of what some of the work would involve.

bisf interior frame (1)


Posted : 12:31 am

That's an amazingly thorough response. I've already been on the phone to Alex this morning regards this so he'll be getting back to me soonish he says. 

The phrase the surveyor used was 'opening up a corner of the building' that sounds external to me, but we could inspect internal first.

Basically, it sounds like work that needs to be done but not a reason to avoid purchasing the property?





Topic starter Posted : 4:10 pm


I think the surveyor is asking the right questions and would like to inspect the most vulnerable areas of the property.

If structural corrosion were to occur on a BISF house, it would most likely occur at or near the base of the corner stanchion legs. However, even if the base of the stanchion was badly corroded, the affected area can be cut away and replaced with a replacement steel section/ support, making it almost as good as new. The repair process, although quite simplistic in nature, does tend to cost over £1000 per stanchion leg, with much of the cost going toward making the external wall good and visually in keeping with the existing wall materials.

I look forward to hearing how you get on.

Posted : 9:29 pm