OK, So here is my LONG list of questions- list of questions related to renovation.

OK, So here is my LONG list of questions- list of questions related to renovation. 1


So I’m a first time buyer and recently submitted an offer on a house which is a BISF- and one that hasnt been touched ever by the looks of it!

It has its original asbestos roof, single glazing, outside toilet, etc the lot just so you get the picture.

So although I’m not exactly an avid DIYer, when I do it I’ve no problem with it and I’ve no problem getting stuck in to a renovation  But there are a number of things I don’t know and in many cases cant find the information on so it would be good of someone/some of you could help to answer! Hopefully people in a similar position to me will find these answers useful to.

So my long list of questions are as follows in no particular order:

1) Some of the paint on the steel cladding is cracked and peeling– I can see no signs of rust or rot visible on the outside bar a bit of wood at roof hight which is hanging down a little (unrelated). Although I ask about this later, assuming I dont get it clad anytime soon it is an eye sore. What would be involved with repainting? Would I need any kind of special paint? Would I have to remove/sand off the existing paint before repainting?

2) External Insulation and recladding with uPVC etc– Although there are clearly quite a number of homes that have had this done, I cant find any sort of hint of costs involved with this bar one comment. Since all semi detatched BISF houses are the same in 95% of cases, Id like to think that other peoples quotes would give it a pretty good indication of what to expect. So for those of you that have had quotes to get this done/had it done- how much were you quoted out of interest?

3) Internal insulation and ventilation– both upper and lower. I have every intent of ripping every wall down internally and rebuilding them with drywall and improved insulation. Now I’ve read a few things on this and got myself confused so would be good to get clarified. For the walls that are part of “the shell” ie the other side is an external wall- do I need to be careful about what times of insulation, and ventilation etc? ie is this not as simple as taking down the existing studwork and insulation, and rebuilding with whatever I fancy? Or am I right in thinking that the ventilation is’nt really something to worry about as there is some sort of gap between where these walls which would be rebuilt and insulated and the part that needs ventilation, as there is some sort of gap that runs from the bottom of the house right up into the loft that you can look down which provides all the circulation needed which would avoid condensation?

4) The back boiler– how do these things generally perform? I intend on removing the steel chimney which runs through the house to better use the living room space but wouldn’t have the funds to go for a new boiler in the short term. I do have fully certified plumber friends I could ask this to but I figure when in rome- as I don’t know what the “back boiler” which is stored behind the gas fire bit in the chimney looks like- could someone tell me if in theory it could be relocated simply enough? Or is it some sort of very odd shape/size that would be awkward to rehouse somewhere (loft? future utility room? etc)?

5) A door next to the stairs– this one may be unanswerable but figured its worth asking. I’ve seen a number of people open up the living room by removing the hall. Linked to this (although this is hard for me to picture), I wonder whether it is possible to put a door in the wall the opposite the living room -side of the stairs (ie the side the stairs go up- right at the foot of them)? I can see on some of the structural pictures on this website there is a steel bar of some sort that goes through this wall- I wonder if it could be possible to put a door at the foot of the stairs to access the storage room on the other side without going through the kitchen? I’ve not seen this done, discussed, or seen anywhere so I just wondered if its possible or whether removing and somehow resupporting this steel bar would be a major piece of work.

6)“Bringing the outside in”– As I mentioned in my top post, this still has the downstairs toilet as “outside”, I wonder if anyone on here bought there house like this also- in which case im just wondering if someone could tell me roughly how much it cost them/would cost to have this bricked up and a door put in so that this becomes a proper inside space which I can create a utility room etc from.

7) Porch– The house has the original lip roof over the door way but it may be quite nice to make this more of a proper entrance (which would help with reducing drafts if I was to ever open up the living room)- again I wonder if anyone here had a more proper porch/entrance built to the front and roughly how much it cost them?

8) The roof.. the roof….the roof is…asbestos– So again did plenty of reading on this and it sounds like I really only have one option for mortgages with its original asbestos roof- Halifax. Luckily this is who my mortgage promise is through so Im feeling more confident about this. From what I read a replacement roof would likely cost in excess of 8k+- Im assuming there are no alternatives to this to “make the roof “safer/more mortgageable” in the future without completely replacing it?

9) Full surveys. Because the outside of the place does look pretty and other than having its electrics brought up to more current standards the house showing no signs of any real “care” being taken to it, naturally Id like to have a full survey conducted above and beyond the simple valuation one required by the bank. As BISF is more of a specialist market- how does this work (this probably shows my ignorance to the buying process)? Will the bank do its own survey, then I of my own free will can find and appoint a surveyor who actually knows BISF properties? Or if I asked the bank to do a full survey would they likely find someone that knows that they’re looking at/could I nominate a surveyor to them?

10) Another way out– I see quite a number of people have conservatories leading off from their dinning room and as a result have had french doors put in where normally the window would be. This is probably a silly question, but is there alot of work to get this done? Or actually because there was already a window there any appropriate plinths etc are likely to be fine so its just a case of removing a some additional breeze blocks and fitting doors instead? Im just thinking ahead as I will need to get double glazing installed and wondered if its worth getting this done rather than replacing that back window/

11) Chilly round the edges!– If I can secure this deal, Il be moving in during the coldest time of year- and given I wont be able to afford to immediately re-insulate the whole house etc Im wondering if someone can tell me just how badly inefficient these houses are at retaining heat and letting in draughts? The EPC for the property actually rates it currently as D which I was surprised at- and the only real action relating to heating etc is just draught proofing (which also makes me somewhat sceptical as surely they would encourage double glazing as quite a big way of making energy savings?!)- so how cold is the place likely to get compared to a typical house? Or are they actually not that bad at all but just could be better?

Thats all I can think of, so thank you for taking the time to read this essay and hopefully I can get this deal done and if I do there will certainly be an almighty project write up to follow!

Thanks in advance for your input :)



  1. So interestingly on my searches for all things BISF… I found a BISF house with near enough the exact layout I am aiming for when I convert the “outhouse" to a permanent part of the house- most key here is the fact they have put a door in at the entrance of the stairs as Ive described! Unfortunatley there are no pictures of any of the relevant stuff :(

    I guess I would need to speak to a structural engineer to find out if the brace in the corner is actually safe to remove?

  2. Heres a picture of the front by the way- so you can get a feel for what Im up against! Its bad enough the paint is flaking… but the colour…! And this gives you a pretty good feel for how much work the overall property needs… but equally why I would like to get a full structural survey carried out :-/

  3. Hi Trish, thanks so much for your comment Smile

    Ed- Thank you for your comments, it sounds like I still have alot to consider for sure! I really dont like the size of the fireplace as to me it really ruins the space of the room and limits its layout so sooner or later I will definitely remove it all. Its not so much the efficiency of the boiler Im overly worried about, its simply more the cost of a replacement! But luckily Ive got a very good friend whos a qualified plumber so Im hoping he can help me devise a cost efficient solution! Microbore as far as I know isnt an issue, I rent a new build currently that utilises microbore and I believe this is very common in most new builds due to how much cheaper and quicker it can be installed, so finding a compatible boiler really shouldnt be an issue- although I guess time will tell!

    Regarding heating and draughs etc, as I mention Im currently renting a 3 bed new build built in the last 2 years, so as you can imagine its VERY efficient and well insulated so its going to be a trade down, but I spent most my life in a fairly sizeable bungalow with large rooms and not the most efficient heating and brick walls with no insulation etc so I guess it cant be too far of in comparison, I was more concerned with the fact the EPC recommended “draught proofing" I just had this horrible feeling it would be quite hard to manage the heat- but sounds like if I find the key draughty areas it should be simple enough to manage!

    Im really not sure why the paint is cracking, but its the only layer of paint there as underneath is grey but it certainly really lets down the look for the property. It does sound like my worst fears for the pricing of cladding was actually based on a full external insulation option aswell, a few grand isnt too bad- and a friend did suggest that as I need to get double glazing installed I may be able to negotiate one company to do it all at the same time and maybe get a good price.

    On my search for a buildings surveyor I keep comming up with the same feedback- that its unlikely that the owner will allow a proper survey as it would require making holes etc in the property- and more to the point that to get a proper feel for its conditon you would need to inspect each of the 4 main pillars, as just because one looks good, doesnt mean the rest are. The house is owned by an investment company at the moment and I believe the previous occupants must have passed away so as such it isnt actually inhabited currently, I wonder whether the corperate owner would actually allow this kind of survey- but if not- is there much point getting a homebuyers survey rather than a valuation survey? Given I will be gutting the house and starting again through time, what is the survey likely to pick up that I maybe wouldnt have noticed myself? For me Id be more concerned with the state of the actual steel structure but if I cant get that surveyed properly it almost seems a little pointless having anything else….. thoughts?

  4. Hi Grangey and welcome! Now I have a little more time I’ll also answer some more of the questions I can.

    Exterior painting – I don’t know much about this and am in a similar position. My house is covered in a strange paint with fine grit in it which gives a (horrible in my opinion) textured surface. It has started to flake away in places exposing the normal paint underneath. There is no sign of rust so it’s only cosmetic for now. Ideally I’d like to repaint it in a nice colour, like my neighbours which is yellow upstairs and while below which looks very pretty and Scandinavian. I removed some of the grit paint that had been splashed onto the window surrounds with paint stripper, but I think stripping a whole house would be too big a task!

    External uPVC cladding: I had a leaflet advertising it for 2400. As Marc mentioned though, it does need cleaning to prevent it getting grubby. That price was without insulation, I believe external insulation would cost 10-20k.

    Internal insulation: I think if you are rebuilding the dry-lining, it doesn’t add that much work or cost to do internal insulation at the same time. You’re right that the wall cavity that you can see in the loft extends right down to ground level. I believe it is essential to prevent condensation forming on the inside of the steelwork so you need to avoid blocking it. To be safe I also used Gyproc dry wall sealer as a vapour control layer to prevent warm damp air from inside the house getting to the steel, but you could also use foil-backed plasterboard instead I think.

    Back boiler: when I had this serviced, the engineer recommended keeping it as in his opinion they are very reliable and cheap to maintain. It seems that unless you use a lot of gas, it would take a long time to repay the cost of a new boiler through it’s higher efficiency. Definitely better loft and wall insulation and better heating controls (if necessary) will save money quicker. Unfortunately the boiler and gas fire in front of it cannot be separated so you can’t relocate it. I don’t even know what our longer-term plans for the boiler are, probably keep it until gas prices rise too much or it fails! The other thing you might have like us is 8mm or 10mm microbore central heating which I don’t know will work with a new boiler, but the microbore pipework is much more practical in a BISF house as it can fit between the steel floor beams and ceiling boards (which cannot be drilled or notched for standard thickness pipes like wooden joists can).

    Door next to the stairs: I don’t know anything about this. Our outhouse starts further back so a door here would go back outside! The diagonal brace is to keep the corners of the house square. I would guess that they are designed with a safety margin and you could remove one and the three others in that corner of the house would do the job, but that’s just a guess and I wouldn’t remove one myself!

    Outhouse: I understand that most BISF houses have a wooden outhouse, but in Bath they all have one made of a single-skin of concrete blocks. If it’s wooden I would think it would need to be rebuilt completely if you wanted to use it as a proper room. Certainly ours is not designed to be a habitable room as it has no insulation and is very cold in winter.

    Porch: No idea – porches are a pet hate of mine! ;) Always look like stuck-on afterthoughts in my opinion!

    Asbestos roof: Someone came to the door with a quote of 3k for a new roof. As i’m not looking for a new roof, I declined. Later I heard from my neighbour that that didn’t include the cost of disposing of the asbestos and he did it all without scaffolding! I heard someone up the road had theirs done for 11k. It seems the original asbestos has a good few years left in it and isn’t hurting anyone undisturbed up there so I think the only pressing reason to replace it would be to make the house more sealeable or if it started showing signs of deterioration.

    Survey: can’t help you on this one unfortunately. A friend of my dad’s who is a steel engineer looked at it while posing as a decorator to the estate agent. The main problem is most structural problems that may be present can only be revealed by opening up or at least boring into the walls, so I just took a chance on this one as the general opinion seemed to be they are fairly rare.

    Conservatory: Not sure on this one, but it’s not uncommon to remove the wall below the dining room window to put in sliding doors there. The outer layer of the wall downstairs is about 50mm thick and made of concrete render on steel latticework laths. It can be cut through with some sort of angle grinder, probably hard work but not especially difficult.

    Chilly: You’ll probably find it is better than you expect. What type of home did you live in before? That will probably determine whether you find it cold or not. Compared with our previous Victorian solid-wall flat it’s quite warm. I’ve done a few calculations with this: http://www.vesma.com/tutorial/uvalue01/uvalue01.htm

    The value for the original downstairs walls of a BISF house comes out as 0.58W/m2K (assuming 50mm of glassfibre insulation (difficult to tell how thick it really is) which means they’ll lose 0.58 Watts per square metre per Kelvin difference between the internal and external temperature. If you put in the figures for a solid masonry wall it is 1.62 W/m2K (assuming 25mm of plaster and 200mm of brick) which is almost three times as much!

    One thing I did find was that if there are holes in the internal wall linings such as where the pipes come into the meter cupboard and around electricity sockets you get a strong cold draught, so it’s worth plugging them up at least temporarily.

    Hope this helps,


  5. Hey congratulations too Grangey, I hope the survey goes well for you too.

    You know, I honestly don’t think you can get a better value house that’s so easy to upgrade. OK, it’s a shame you have the biggies like the roof to sort out first but I love my house and would never swop it for a normal brick one.
    People do have preconceived views through ignorance, liking our houses to prefabs because of the steel part of the outside but that’s where the similarity ends. Thanks to this website and everyones input, especially ed and his projects, I have learn’t so much and I’m now proud of my house and its history as well as eager to take on some new projects.

    Anyhoo I ramble lol, good luck and fingers crossed Smile


  6. Congratulations Grangey! You’re in the same position we were almost exactly a year ago as first time buyers Smile

    Just a quick post, but I’ll reply more later. I wouldn’t worry too much about the cold this winter as a BISF house isn’t as poorly insulated as a lot of people would imagine. It’s not great by modern standards, but it’s far from the worst and in fact better than any traditionally-built non-cavity wall house ie anything from before the 1920s/30s. It’s certainly noticeably better for example than my parents’ typical 1900 end-of-terrace with solid stone and brick walls. I think people like masonry, because it’s familiar and traditional but thermally it’s rather poor unless you stick some insulation layer in between.

  7. Marc thanks for your detailed responses, really helpful thank you!

    Unfortunatley no news today, apparently the investment company that currently owns it takes a while to get back to the agent but fingers crossed Il hear back tomorrow.

    Anyway following on from the comments:

    Sara thank you for your comment, I didnt have the report with me at the time but since youve pointed out the score of 54 I remembered this is identical to what this one rates currently without double glazing- so it must have been E not D, but none the less im surprised the score is the same as surely double gazing has a BIG effect on green footprint so Im sceptical about the report now.


    1) thanks for your point on paint, I was hoping it might have been easier than harder but does sound like a pretty labourus unenjoyable task so may just find a contractor to take care of this, but Ill see how bad it really is should I get the place.

    2) I wonder if Ive been getting confused between just having the outside clad, and having external insulation put on then clad. The £2-3k you mention is more promising than I was expecting based on what I had read, was this for full external insulation or just to have the steel exterior replaced with upvc cladding? Or am I confusing myself here?!

    3) Thanks for the link, I had indeed seen marcs post but funnily enough I didnt see all the comments and hidden pictures, ive given this a full read now and that certainly answers my questions on that for now thank you!

    4) Ah I didnt realise it was linked to the fire as one, thatl be another boiler to add to the job list then! Thanks for clarifying.

    5) Very interesting, I havnt been able to find any pictures or floorplans that indicate a new door put next to the stage so great to know its possible. Its certainly something Il take your advise on and get a proper structure engineers view on as Im sure there are repercussions of removing one of those braces that I wouldnt want to find out!

    Thanks so much for all input so far Smile


  8. Hi Sara
    The comment box should have moved down as you typed but it appears that this did depend on which browser you were using.
    I have now made the comment box larger and added a Scroll bar on the side.
    I hope this helps


  9. We have recently bought our BISF house and did some internal renovations just before moving in, but not to improve insulation yet. I just thought it might be interesting that the EPC rating given to us showed that the house only achieved a score of 54, which is still just E category. Double glazing had been installed on it by then, so in theory it should be higher than for the house you are buying.

    I’m sorry, this doesn’t seem to let me type more than 5 lines at a time, so I’ll just post this for now.

    a da a di

  10. Welcome to BISF House Grangey, it’s good to have you with us!
    Firstly I would like to congratulate you on buying (or about to buy) a BISF House. Out of all the properties on the market, the BISF house in our view represents the best value for money and is perhaps one of the easiest types of house to renovate. Walls can easily be removed or replaced, insulation can be added and your home can be re-styled to suit your own personal choice and design.
    Some of the questions you have raised are amongst the most frequently asked here at BISF House and there are a number of posts here that do provide answers to some, so where possible I will include links for you. The website has just undergone a major overhaul and we are still ironing out a few kinks. We also need to provide a better category menu to make it easier to find answers to questions such as yours. :0)
    I hope also that other members will add further input for you, as there are often a number of different ways to tackle any one topic with a BISF House.

    1) Some of the paint on the steel cladding is cracked and peeling.
    All BISF houses are ex local authority. The Councils used to be responsible for painting the outside of the property which they did on average every 3-4 years. In the vast majority of cases the painting process went ahead with no problems however from the late 80’s problems started to appear with paint adhesion. This was possibly because of changes in the manufacturers paint composition but more likely due to the use of cheaper / inferior paint. These paints were not suitable for metal surfaces which expand and contract due to changes in temperature. The result was unsightly cracking and peeling to the steel cladding as you describe. Some painting programmes were put on hold for years until suitable products could be found and some houses have never been repainted since, depending on the Council.
    There is no hard and fast paint remedy. You will need to remove the flaking paint and sand down the surface which is no mean feat. Then you will need to apply a suitable undercoat and surface paint formulated for exterior steel. You may find a product that is self-undercoating but you do need to seal the underlying layer to reduce the risk of paint reaction. You may well need to question the manufacturers about the suitability of your chosen product but speciality paint may well perform better than a DIY store brand. It would be a tragedy if it peeled again after so much hard work.

    2) External Insulation and recladding with uPVC etc
    UPVC is one of the most people choices for upper cladding, partly due to its speed of installation and low cost (at least to the installer). I have re-clad a number of houses both upper and lower level. The process itself is very easy to the upper storey but gets a little trickier round the eaves etc. I have also had one property clad as part of a conservatory deal and that cost me around £1500.00 about 5 years ago. The installers on that job just used ladders which is not exactly Health & Safety conscious.
    I have heard of prices ranging from £2k -£3k but I will leave others to give you there costs and quotes. The cladding itself is very cheap to buy particularly if you have a trade contact.
    Don’t forget though, cladding is not maintenance free and it does require cleaning to keep it looking fresh.

    3)Internal insulation and ventilation
    You’re partly on the right track here with internal insulation. Taking the internal route is by far the cheaper option and one that can be carried out by a competent DIY person. External insulation is far more specialised and expensive.
    Ed, one of our senior members here at BISF House, has just completed an internal renovation project to a rear bedroom. Take a look at his excellent well documented post HERE. It covers your question pretty well and I’m sure that ED may drop by here and give you some of his valuable input.
    In short though, it is imperative that air circulation is maintained within the cavity to prevent condensation forming on the steels or on the surface of the steel cladding. You can fill the cavity with insulation and some people choose mineral wool for this but we strongly recommend a solid insulation such as Kingspan. Mineral wool tends to collapse over time and it can droop down in the cavity and rest against the steel claddings inner surface and prevent airflow. Condensation can then build up due to the reduced ventilation which you need to avoid,
    Kingspan can be purchased in various thicknesses. By choosing the right thickness it can fill the stud cavity without resting against the steel. Even if say the top of a piece of Kingspan falls forward onto the steel through wall impact, it still will not prevent airflow but we do suggest that it is fitted as snug as possible to avoid this. Thermal bridging is also avoided using this method as thermal bridging will cause a build up of condensation on areas of your inner walls.
    4)The back boiler
    In original form BISF houses were fitted with a coal fired back boiler but from your question I understand you have a gas back boiler, possibly a Baxi Bermuda.
    This back boiler cannot be operated independently from the fire nor can it be relocated and operated on its own. The Baxi back boiler by todays standards is very inefficient. If you still have good quality radiators that do not have micro-bore piping I would strongly suggest a new boiler. In some cases depending on your circumstances, grants are available toward the cost of a replacement boiler. A new complete system starts from around £2.5k. A new boiler can be purchased for around £800.00. I would ask a Gas fitter friend to install a new boiler as it would probably work out cheaper and certainly be easier.
    5)A door next to the stairs
    I have seen several doors installed at the foot of the stairs that lead into the outhouse or garage area. Doing this allows you to have more kitchen cupboard and worktop space. The steel support that you refer to is a brace. It is designed to reduce the frames movement from expansion but it’s effectiveness has often been questioned. I have not undertaken this myself not have I seen the construction process of this carried out. If you do intend to do this I would suggest replacing the brace with a suitable horizontal support above the door frame. I will be posting some new better quality images of the BISF frame shortly and this may help you decide if this is an option for you.
    To be honest though, as this would require a structural modification, I would strongly suggest contacting a firm of structural engineers. AJ Balfour may be able to help you. You can visit their website HERE.
    Sadly I will have to sign off for now as it is now past 1am. I hope I have been of some assistance so far. I shall try to answer more of your questions shortly but I may well be beaten to the post by some of our other members. :0)
    My regards