Buying a steel framed house


We are interested in buying a steel framed house.

The house is currently cash buy only because of slight corrosion to the steel frame. The survey has revealed evidence of corrosion at the bases and surface corrosion within the loft. Apart from that, we cant find no more information.

Is this is a big job to repair? Can anyone help us out on how much it would cost to make the property mortgagable? Would be just be able to treat the surface corrosion and replace the bases?

Will we not know the extent of the damage until the steels are exposed?

We have the chance to buy a cheaper house and be mortgage free but we do need help and advice if anyone has done this type of work or job before, please advise.



  1. Hi Gemma,

    I have just purchased a Dorman Long House. I need to do some upgrades such as re-wire/central heating/insulation of some sort and I am trying to find some plans and specifications for the building. I found this site and was very interested in your posting and very supportive and helpful replies. I wondered if there was an update on your position and experience 2 years on.

    I have read the guidelines given by the council for mortgage lenders and they seem quite relaxed by this form of construction as long as the cavity is clear allowing for ventilation reducing the risk of the steel deteriorating – Did you manage to get a mortgage.



    If anybody

  2. Hi

    Thanks for your reply and information.
    We have now found the contractor who has just regenerated 40 dorlonco properties in the next street. We are going to contact them tomorrow for some extra guidance. Hopefully this will help us to make our decision into whether buying the property.
    We are looking at staying there for years and gradually doing the work.

    Thanks Gemma

    1. That’s great news Gemma!
      Please let us know how you get on as your input will no doubt help others who may be in a similar situation.
      I do wish you the very best of luck and I hope that you will get some positive views from the company.

      Marc Smile

    1. Thanks Marc

      They are not regenerating that area where we are looking to buy the house, so i am going to ring the local council on monday and see what they are doing to prolong the life of the dorlongo houses within the area.
      Surely all houses in that street would be of the same construction and damage to the steel frame? They just havent found out because they havent tried selling their house? Is that correct?
      So do you think it would be a big gamble to buy this house? Would we loose our money? Could the property potentially start to subside?
      My partner is an industrial painter, so he is confident he can sort the surface corrosion within the loft area and walls if exposed.
      So these type of properties are prone to concrete cancer? Is this where the money is to repair?


      1. Hi Gemma and Marc,

        The houses on the street are not necessarily all of the same construction although most system-built houses were built in batches as it were. For example on my road only the first two thirds of the south side of the road has BISF houses, the rest are traditional houses. Also I notice that looking up Dorlonco houses they seem to look very similar to traditional houses from the outside so unlike a BISF house it might be difficult to tell what is a Dorlonco house and what isn’t. To me it looks like a very typical older brick house and I would never have guessed it had a steel frame.

        I think it’s difficult to tell whether all the houses will have a similar degree of corrosion because it will depend on a number of things. If it’s caused by condensation from moisture generated inside it will depend on how previous inhabitants have used them over the years. If it’s caused by water penetration from the outside it will depend on how well maintained the outside has been over its life, things like whether the pointing has been maintained, gutters prevented from overflowing onto the walls etc. and also on the aspect (whether it catches the rain or not).

        One thing I would say based on experience of a BISF house is that you need to speak to people who have actual experience of your house type, people who live in or work on Dorlonco houses and also to take things that people without direct experience say with a pinch of salt. Unfortunately it seems Dorlonco is a lot rarer than BISF so you might have more difficulty. I also notice that the Dorlonco house is older than the BISF house, dating to 1919. Perhaps Marc knows more about this, but I thought the Housing Defects Act only covered post-Second World War houses so the fact it is lot listed as defective might just be because it wasn’t covered, not that it isn’t defective.

        Coincidentally, I noticed the name Dorman Long on the steel stanchions of my house, so they obviously had a hand in the BISF house as well!

        Anyway, good luck and I hope you find the information you are looking for,


      2. Hi again Gemma
        I think the the main risk with this property is not knowing the true extent of the defects as no invasive survey has been carried out.
        The risk of the frame being worse than expected is very real and perhaps a gamble is a better description as the corrosion may or may not be extensive and the floor structure may be fine but again it may hide problems.
        From previous research I know that Dorlonco houses identified as having structural defects are very hard to sell and even harder to mortgage and this could be why this property has appeared at auction.

        Many Councils in the past have chosen to demolish and re-build rather than repair due to the costs involved.

        If this were a BISF property in that location and at that price, even with corroded rear Stanchions I would have had no problem in buying the house because I know that the repair could be completed at a reasonable cost by a competent builder. This is mainly due to ease of access with a BISF house as stated before but a Dorlonco frame is not as easy to access and repair which ultimately raises costs.
        From the surveyors report we are only surmising that there may be a problem with the first floor and it is better to consider that there may an issue rather than to discount the thought and face an unexpected shock later.
        The surveyor has specifically pointed out that this has not been inspected but it is a known issue to cover himself and to avoid any comeback later should you find that this too is defective.
        The “Concrete Cancer" issue mainly affects PRC type houses built using Precast Reinforced Concrete, A Dorlonco house is not a PRC house but the first floor was laid using this same method. Steel of this era was of a lower quality than steel used in buildings today and as a result is more likely to be affected by the carbonates in the concrete.
        If this ever needed to be replaced, the entire house would have to be vacated during the repair process and the property would require new flooring, ceiling panels and decoration throughout. If central heating is installed this could also be affected and may need to be replaced depending on the heating pipe locations serving the radiators and boiler..

        If you are paying by cash and intend to live here for many years then the cost of this work could be spread over the years to come. If you intend to buy using a mortgage you may find that the stanchion repairs need to be made before the funds are released or as a condition of the mortgage.

        As Ed said previously I would seek the advice of a specialist Dorlonco repair company as our views are conjecture only with no professional knowledge in Dorlonco defects.
        Many people might say the same about BISF houses out of ignorance but we know different here at BISF House and so do our members. Sadly though we can’t reliably extend our knowledge to Dorlonco houses as we have no experience with them.
        I wish you well and I hope you choose to make the right choice whatever that may be. I will include a Birmingham Mail article below relating to Dorlonco owners in the Birmingham area who were unable to sell their homes back in 2002 as it seems to reflect a common issue with these houses.

        £100,000 houses that can’t be sold

        Sep 29 2002

        By Martyn Leek, Sunday Mercury

        They are the £100,00 homes their owners cannot sell – because council chiefs claim they are unsafe.

        Linden Road residents in Bournville, Birmingham, live in Dorlonco houses which were unconventionally built of steel and concrete, rather than bricks and mortar, in the 1920s.

        In 1987, the city council told homeowners their privately-owned properties may need to be demolished in 10 years time as metal supports could have dangerously rusted away.

        Yet no demolitions have taken place because the authority has only offered £13,500 for each house – despite others in the road regularly selling for more than £100,000.

        Now the householders, who claim their homes are perfectly safe, have been left in limbo and unable to sell up because the council has officially classed them as defective.

        The council is also refusing to carry out remedial work to add a protective “brick skin" to the houses. Families say it would cost £20,000 per house but the authority claims the cost would be nearer £50,000.

        Roger Keay, 48, said his parents were only told about the possible defect a year after they bought the house for £30,000 on the open market in 1986.

        He said: “Nothing came up on the survey but then they were visited by council officials a year later. They said the house was unconventionally built and would only last for 10 years before it was overcome by defects and then have to be knocked down.

        “Well, that was 16 years ago and they are still standing."

        Mr Keay, a retail manager, said the council had offered his parents just over £13,000 to take the house off their hands. “If they think the house is that bad and something needs doing they should pay us the full market value instead of offering us peanuts for it," he said.

        Neighbour Raymond Carr, a retired surgical fitter, bought his house from the council before he was aware of potential defects more than 30 years ago. “There is nothing wrong with these houses," he said. “The council said you could not fit double glazing and central heating but we have. But if we ever wanted to sell them, this blight of being unconventionally built would rear its ugly head.

        “We have tried the council, MPs and the Local Government Ombudsman and we are getting nowhere.

        “These houses are fine. They are structurally sound – yet we have to live with this millstone round our necks.

        “Each year the city council come round and check them and say they are okay and then we have to wait until the next year. In the meantime, we can not sell them."

        Under a government compensation scheme, certain types of nontraditional houses can be sold to the local authority for 95 per cent of the defect-free value.

        But Dorlonco houses are not included in the scheme.

        “We have been in limbo for all these years," blasted Mr Keay. “We are afraid of spending too much on the houses in case we are told they need to be pulled down."

        Last night, a spokeswoman for Birmingham City Council said they had been aware of defects in Dorlonco houses since the 1980s and had to demolish some of them in Washwood Heath in the late 1990s.

        The council was under no obligation to survey the privately-owned properties, she said, adding: “We will continue to survey our own houses and there is an open offer to privately-owned occupiers to be included."

  3. Hello again Gemma & Brett
    I have had a look through the report and the first point that I should make is that the report relates to a Dorlonco house which has very few similarities to the BISF House other than it does indeed have a steel frame but this is where the similarity ends.

    We have extensive data regarding BISF house but sadly very little that relates to Dorlonco but I will give you my own personal view based on what I am aware of.
    The Dorlonco house does have a number of inherent defects however they are not listed as defective under housing act legislation which is good news.
    The survey mentions light corrosion in the loft space, this is of little concern and can easily be remedied with a simple treatment of rust preventing paint or primer which can be carried out on a DIY basis.
    A small portion of the stanchion frame at the front of the house has been inspected and found to be lightly corroded but you should understand that in a Dorlonco house the framework itself is very well hidden inside the walls of the building which makes it very difficult to assess properly.
    There could well be hidden areas of more severe corrosion that has not been seen and thus not entered into the report.

    By far the most serious problem is the mention of more severe corrosion to the stanchions at the rear of the house and the recommendation that they would need replacing in the near future.
    The rear of the buildings steel frame appears to have suffered more from corrosion possibly due to its aspect and exposure to wind and rain, this may also suggest that the exterior walls at the rear of the property are not water tight and may be accelerating the corrosion.
    Surface corrosion is common on most steel frame buildings including houses, flats, factory units and even supermarket stores such as Asda etc. Serious corrosion is less common but frequently found where water has been allowed to seep through from the outer walls or because there is not enough ventilation allowing moisture / condensation build up from the inside.
    Indeed from time to time BISF Houses suffer from severe Stanchion corrosion but in a BISF house it is relatively easy to access the parts concerned as there is only a thin layer of render to get through. However it is much more difficult in a Dorlonco house as the walls are thicker and require supports during the repair process and sadly difficult often means expensive.
    I am aware of several Council projects to renovate BISF Homes that had to be shelved due to the sheer amount of structural work required to repair corroded Dorlonco as the budget to due so spiralled out of control.

    The report also records concerns over the first floor construction which contains steel reinforced concrete which may well have deteriorated.
    Even though not inspected, steel lathe reinforced floors of this period often suffer from carbonation or concrete cancer as it is often referred. In simple terms, chemicals in the concrete react over time with the embedded steel reinforcement causing significant corrosion to the steel lathe and crumbling or breakdown of the concrete itself. This alone can be very costly to repair running into tens of thousands of pounds.

    Together these two repairs alone could easily cost over half of the value of the house and that is being conservative. They could escalate to more than the total value of the property as more surfaces are exposed and faults discovered but in all honesty this is only an estimation.
    I would in the strongest terms possible suggest a full invasive structural survey if you are serious about this house. You may find that the condition is better than envisaged but there is also a possibility that it will be worse, much worse so please seek expert advice first. Such a survey may well appear expensive but it could well save you from losing over 50K of your hard earned money.

    Remember though, Dorlonco houses are not my specific area of knowledge but I do know that repair costs will be considerably more than if it were a BISF house due to the construction materials used.
    I hope this helps in some way. Smile

  4. Thats fine to reply to that address, its our own business so only i can see the emails. We need to put our bid in on the property within the next few days, so let me know what you think and get back to us as soon as you can

    Thanks Gemma

  5. Hi Gemma
    Yes can send it through to @bi*.com" data-original-string="L43v3JfR5uFDawGze5/2DNn8IDDPXH/6q3hqqT48sYw=" title="This contact has been encoded by Anti-Spam by CleanTalk. Click to decode. To finish the decoding make sure that JavaScript is enabled in your browser.">ad@bi*******.com
    I can have a look through and perhaps get a better idea from the actual document. I’m due to leave the office for a couple of hours but I can update you on my return.


  6. Hi BrettandGem & welcome to BISF House!
    Surface corrosion in the loft is a frequent occurrence often caused by inadequate loft insulation. The warm air from the rooms below rises through the ceiling and hits the cold steel frame of the roof support causing surface corrosion. The fact that it is only surface corrosion should not cause any undue concerns however deep corrosion would. I have yet to see 1 single BISF house that does not have surface corrosion in the loft as it is almost impossible to prevent. This would simply require a coating of a good quality rust inhibitor to prevent the corrosion from getting any worse.
    Corrosion at the bases however could mean any number of things. Did you have an intrusive survey or do you have any images of the corrosion that you could show?
    I suspect that you may have had a an intrusive survey as there is no other way to identify stanchion corrosion other than via a boroscope. On the other hand your surveyor could be referring to corrosion of the steel lathe that the render has been applied to.
    Either way can you provide us with a little more specific information from the survey as it really does make a big difference?

    My regards