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Housing (Thermal Insulation)

Volume 885: debated on Tuesday 4 February 1975

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12.27 a.m.

I am grateful for the opportunity to direct the attention of the House and of my hon. Friend the Under-Secretary to what is certainly a serious problem and a national one. When we are not thinking about inflation, probably the next most serious thing on our minds these days is energy saving. We know from various actions and pronouncements that the Government are in earnest about this, and that makes the matter which I am raising tonight all the more extraordinary.

From all that we have heard we cannot fail to be aware that the Government are examining all reasonable ways of avoiding wasteful use of energy. These include cutting down on domestic fuel consumption. In a debate on 19th November on housing insulation the hon. Member for Sevenoaks (Sir J. Rodgers) pointed out that nearly half of our entire energy consumption was used in heating houses and other buildings.

In replying to that debate on behalf of the Government my hon. Friend the Member for Manchester, Ardwick (Mr. Kaufman), who is to reply to the debate tonight, made particular mention of improvements in the Building Regulations with regard to thermal insulation. However, it now appears that something in the Building Regulations themselves hits against the very case that the Government have been arguing. Regulation C9(2) of the Building Regulations 1972, as amended, has cast doubt on one of the principal methods of thermal insulation—cavity wall filling. Local authorities have been put in a position of uncertainty, and at the very least it now looks as though insulation schemes will be held up—indeed, in my constituency they are being held up—and this at a time when energy saving is an urgent concern.

Regulation C9(2) covers the prevention of damp in certain cavity walls and states, among other things that
"in any such wall, wherever a cavity is bridged otherwise than by—
  • (a) a wall tie; or
  • (b) a bridging which occurs at the top of a wall in such a position that it is protected by a roof, a damp-proof course or flashing shall be inserted in such a manner as will prevent the passage of moisture from the outer leaf to the inner leaf of the wall."
  • The filling of cavity walls to achieve thermal insulation has been accepted practice for several years. There are various materials available for cavity filling, and for the purpose of my argument there is no real difference between them. The cavity wall system of construction has in post-war years been the predominant method employed for dwellings of up to four storeys. Thus it has an important role to play in the energy-saving programme.

    What has now come into question is whether the filling of the cavity in the various ways which have been in common use constitutes the bridging to which the regulations refer. If a bridging is so created, the fear would be that moisture might be transmitted from the outer to the inner wall, causing dampness. I want to make it clear that I am not suggesting that we should take risks over dampness. However, we must judge this according to the evidence and in proportion to the benefits to be realised from better insulation.

    The filling of cavity walls has been going on for some time, and not only in this country. It has been accepted by local authorities and by the Department of the Environment. It eliminates condensation in homes. This brings peace of mind to the occupants and a reduction in maintenance costs to local authorities in the case of local authority housing. It can also produce dramatic savings in home heating costs.

    It has been shown that, on the basis of insulation with urea formaldehyde foam, savings of 20 to 30 per cent. on average in fuel costs can be achieved in a centrally-heated home. A particular advantage of this material—the principal filling material—is the low energy cost in production and installation.

    The energy used is the oil equivalent of 114 kg, while the average saving in a year, I understand, is 180 kg. The net saving of 66 kg in the first year would rise to 180 kg per year for the rest of the life of the building. There are still some 10 million homes which have not been insulated, quite apart from the work to be done on new homes as they are built and for which the system is suitable.

    Cavity wall filling is not something which can be carried out in every house, because each site has to be examined by technicians for suitability, and reputable companies do this. Even so, this system obviously has very considerable potential.

    The apple cart has been upset, however, by a determination under head (b) of Section 67 of the Public Health Act 1936 issued by the Secretary of State for the Environment early in 1974. He was asked to rule on a case involving the application of the regulation to the filling of an external cavity wall with foamed urea formaldehyde. His ruling was that the proposed filling of the cavity wall would constitute a bridging of the cavity and that, as it did not include the insertion of a damp-proof course or flashing, the proposed work could not be regarded as satisfying the requirements of Regulation C9(2).

    The Building Regulations are for the guidance of local authorities, and they can in certain circumstances waive them. The validity of cavity wall filling has hitherto been widely accepted. Now, however, local authorities are beginning to pick up the Secretary of State's determination and are stepping in to refuse cavity wall filling operations. It is, of course, open to the householder to appeal for a waiver of the regulation by the local authority, but this makes for delays, especially where the authority insists on dealing with every case singly.

    It is at this point that the matter starts to become extraordinary. My right hon. Friend placed before Parliament new Building Regulations which came into effect on 31st January. In Part F dealing with thermal insulation, urea formaldehyde foam is quoted in a schedule as a material and system which is deemed to satisfy the regulations. Moreover, in the debate on 19th November to which I have already referred my hon. Friend the Under-Secretary, in talking of home insulation, said:
    "In appropriate situations, cavity-filling foam or fibre insulation material can be used".—[Official Report, 19th November 1974; Vol. 881, c. 1281.]
    It would seem, therefore, that the Department does not after all disapprove of these methods of cavity wall filling. Yet we have also on the record the Secretary of State's determination which seems to say the opposite.

    I believe that my hon. Friend was quite right in what he said on 19th November. In practice there has been little to suggest that the risk of dampness has been heightened by the use of cavity fillings. Manufacturers of urea formaldehyde foam insist that their product provides a resistance to the passage of water between the outer and inner walls and, therefore, is not a bridging in the meaning of the regulation. The experience of several years during which countless homes have been so insulated suggests that they are right, because the instances of any kind of failure are few and far between. What is, of course, important is that each site is checked for suitability before the operation is carried out.

    The main point is that this is a situation which has got to be sorted out, and sorted out quickly before there is a serious slowing-down in home insulation. I cannot believe that there are not a number of possibilities open to the Department and I hope that when my hon. Friend replies to this debate he will be able to give some indication as to which he will adopt.

    The first point to consider is my right hon. Friend's determination. Did he intend it to be as sweeping as it appears? The case in question involved one building in the west of Cumbria in an area stated to be severely exposed and subject to high winds and driving rain. Perhaps my right hon. Friend had in mind these circumstances when making his determination, because otherwise he appears to have gone against the practice of his own Department, the statements of his own colleagues and the apparent firm policy of the Government. I wonder whether he might not issue a sort of supplementary determination limiting the scope of his main determination to the circumstances of that particular case.

    The second point is whether it really can be right to consider the types of cavity wall fillings we have been discussing as bridgings within the meaning of the regulation. I do not think that those who drew up the regulation in the first place had in mind to shut out the beneficial use of these materials. I understand that a submission has been made to the Department arguing that these cavity fillings ought not to be regarded as bridgings. Can the Minister say whether he accepts this point and whether he will make an official pronouncement accordingly? Alternatively, if these cavity fillings cannot be regarded as anything other than bridgings in a physical sense, even though they do not have the effect of transmitting moisture—which is what the regulation is really all about—will my hon. Friend seek to amend the regulation specifically to permit such fillings? I appreciate that it is important not to introduce dangerous loopholes into the regulations, but I cannot believe that there is not some way in which the desired result cannot be brought about.

    Would another possibility be for my right hon. Friend to issue guidance to local authorities to help them in their interpretation of the Building Regulations affecting thermal insulation so that they may not find themselves in conflict with the expressed wish of the Government in conserving energy? The guidance might cover such matters as standards, types of buildings, exposure and the use of reputable contractors.

    Fourthly, I would like to ask my hon. Friend whether he or his right hon. Friend has been in touch with the Department of Energy about this matter. Bearing in mind the steps being taken by that Department to guard the use of fuel, I should think it would be horrified if the consequence of my right hon. Friend's determination was to lead to a slowing down of the home insulation programme. Yet there is evidence—I have it on my doorstep—that this is happening. I have indications from other hon. Members that it is happening in their constituencies too, including the constituencies of my hon. Friends the Member for Durham (Mr. Hughes) and Goole (Dr. Marshall), who, I hope, will have a few words to say presently.

    Not only is this flying in the face of what ordinary sense dictates but it contradicts the plain intention of Government policy, which is to facilitate the thermal insulation of buildings even to the extent of broadening the present grant arrangements.

    So there we have it. A strange situation has developed. I realise that considerable technicalities are involved, but I do not think that that removes the need for a commonsense solution. We have an energy crisis to contend with and we cannot afford to delay conservation measures when the evidence is as obvious as it is in this instance. Nor can we perpetuate a situation in which it could be said that the Government were sabotaging their own wise policy and, as I have explained, their own practice. I hope that my hon. Friend will be able to put my mind to rest and, what is more important, eliminate the uncertainty now threatening to envelop the insulation industry, local authorities and, not least, the economy-minded citizen.

    12.43 p.m.

    My hon. Friend the Member for Redcar (Mr. Tinn) has done the House a service in raising this important subject so soon after the coming into operation of the amendments to the Building Regulations of 1974. I wish to express the concern felt by the aggregate block manufacturers in my constituency about the practical implementation of those regulations and in particular the provisions of paragraph F(3) of Schedule 1 to the regulations, dealing with the new thermal insulation standards.

    There are two such firms in my constituency, namely Plasmor Ltd. of Knottingley, which has about 120 employees, and a much smaller firm, Clinker Block Co. Ltd., of Heck, near Goole, which has a staff of 20, nearly all of whom are engaged in producing the kind of aggregate blocks affected by this regulation.

    Those firms realise that considerable changes will be needed in their processes to comply with the new regulations. They are concerned that there should be sufficient time for them and for the whole building industry to adapt to the new blocks that will need to be designed. In particular I wish to follow my hon. Friend by saying that in any redesign of aggregate blocks consideration will have to be given to new cavity spaces inside the blocks. I am told that in Yorkshire in particular there is extreme reluctance on the part of builders to purchase blocks with holes in them. There is no doubt that the traditions of the building industry will have to change as a result of these regulations. On behalf of my constituents, I express the hope that adequate time will be allowed.

    12.45 a.m.

    I should like to congratulate my hon. Friend the Member for Redcar (Mr. Tinn) on raising a matter of wide concern which the House was frustrated from debating a few nights ago. I should also like to welcome the hon. Member for Melton (Mr. Latham) to the Opposition Front Bench in the continuing quiet revolution which is taking place on the other side of the House.

    I am encouraged by the interest that hon. Members are taking in the thermal insulation of housing. We had an Adjournment debate on this same issue as recently as last November and I know from the weight of recent correspondence how widespread and keen is the concern. The recent dramatic increase in fuel prices makes it important for discussion of the subject to be as informed and as wide-ranging as possible. I am grateful to my hon. Friends for having given notice of the points they wished to raise, but before I deal with them I should like to make one or two general points.

    The question of cavity filling, raised by my hon. Friend the Member for Redcar, has recently attracted much publicity, not all of it good. First, however, I should like to make it clear and confirm what I said on a previous occasion that we consider a cavity filling to be a perfectly safe method of providing thermal insulation as long as it is done in the right way to the right house. We have, in fact, specified it as one of the ways in which our new thermal insulation standards can be met.

    However, if cavity filling is not done properly, or it is done to the wrong house, trouble follows. It needs to be done by an expert, and not all the practitioners in this growth area of the building industry are experts. Not all houses are built so that the cavity between the inner and outer leaf of the walls can be safely filled. Moreover, in exceptionally exposed areas even a suitable cavity properly filled can give trouble from damp penetration unless the outer leaf of the wall is properly weatherproofed. The consequences of a badly done job can be unpleasant and even dangerous.

    I now come to the specific points that my hon. Friend the Member for Redcar made. First, he asked about the determination we gave in a previous case. A determination is like a judgment of the courts in that it relates to a particular case but may be quoted as a precedent, and, like a court judgment, it is based on both the facts of the case and the meaning of the words used in the regulations. The decision in the West Cumbria determination to which my hon. Friend referred was based not on the weather in that area—the fact that the weather in Workington is wet—but on the actual wording of Regulation C9. I must add that we are now considering another application for determination involving the regulation. In the West Cumbria case neither party disputed that the Building Regulations applied to the work. They differed over whether the regulations were complied with. In the present case we are asked whether the Building Regulations apply. In coming to a decision we shall again have to take into account the precise wording of the regulations concerned.

    Secondly, my hon. Friend asked whether these fillings are to be regarded as bridgings. I am advised that this is so, and this was the basis of our decision in the West Cumbria case. We appreciate, however, that Regulation C9 dates from before the days of insulation by filling the cavity between the inner and outer leaf. We shall be keeping the position under review to see whether there is any possibility of revising Regulation C9 to take account of this practice in a way that will provide adequate safeguards against damp or unsafe buildings.

    Thirdly, my hon. Friend raised the question of guidance to local authorities. Only the local authority can decide how the Building Regulations apply to work in its area, and my right hon. Friend the Secretary of State cannot tell local authorities what they should do. We do, however, give guidance from time to time and we shall consider whether we need to do so on this matter.

    My hon. Friend's last point concerns co-operation with the Department of Energy. We recognise the need for co- ordination between Departments on the important issue of energy conservation, and we naturally work in close co-operation with the Department of Energy. But the application of the Building Regulations in a particular case is a matter for the local authority or, in certain circumstances, my Department.

    Finally, I understand that the Langbaurgh Council, in my hon. Friend's constituency, usually takes three weeks to process an application, except when neighbours of terrace or semi-detached houses are given 21 days to comment. I do not think that this can be considered unreasonable delay.

    I should like to take advantage of the wide terms in which my hon. Friend has framed his case to say something about our increased requirements on thermal insulation of dwellings. I am grateful to my hon. Friend for giving me this opportunity to put on record certain matters about which we believe that it is important for people to know. Our proposals have been generally welcomed, but I think there is concern on one broad issue and on one specific provision.

    The broad issue is whether, in the context of the growing need to conserve fuel, our proposals go far enough. Part of the answer to this criticism lies in the statutory powers under which they were made.

    Under the Public Health Acts we can make regulations solely in the interests of public health and safety, and it is under these powers that our revision has been made. Our object was to reduce condensation in dwellings, several years of study having shown that thermal insulation can play a significant part in doing this. Moreover, unlike the other factors involved, such as heating and ventilation levels, thermal insulation can be fairly easily controlled by Building Regulations.

    Nevertheless, the new regulations will make a significant contribution to fuel economy. We are, roughly speaking, doubling the amount of insulation required. To take a fairly simple example, the amount of insulating quilt to be inserted in a roof will have to be increased from 25 to 50 mm. We are satisfied that these new standards can be achieved with no significant increase in the capital cost of new housing and without shortages of insulating or structural materials.

    We are by no means convinced, however, that this would be the case if we were to lay down an even higher standard at the present time. Apart from the obvious undesirability of adding further to the cost of new housing, we are uncertain whether the necessary skills and techniques required to achieve a higher standard are yet sufficiently developed. This applies not only to the manufacture of materials but to the skills and techniques employed on the building site itself.

    We also need to consider very carefully the possible side effects of going to standards of which there has not hitherto been any widespread experience in this country. We are, for example, examining the problem of interstitial condensation which I understand to be the undesirable development of condensation within the structure of highly insulated walls.

    The House will be aware that under the Health and Safety at Work Etc Act, which became law in July last year, we have express power to make Building Regulations in the interests of conserving fuel. As I have told the House on another occasion, we have in hand an urgent study, which we hope to complete in the next few weeks, of possibilities for fuel conservation in buildings of all kinds. The object is to identify the types of building, the technical means most likely to produce savings and the feasibility of achieving them. This involves taking into account the likely pattern of national energy supply over a considerable period, since buildings tend to last a long time. It also means considering action for both the short term and the long term. I stress that the possibilities include not only thermal insulation in its various forms but other possibilities which might lead to equal or greater savings.

    I cannot yet forecast the extent to which housing will be identified as requiring priority over other building types or whether further increases in thermal insulation standards are likely to give greater immediate benefit than improvements in, say, the control of ventilation or heating systems. The House will, I hope, understand that I do not think it wil be right for us to make new regulations until we have assimilated the results of this work.

    There is one other point I should like to make before leaving this general issue of the right level of insulation at the present time. Because the regulations are mandatory, we must be sure that their requirements can be met and that the benefits they bring will be worth while. But the standards they set are minimum standards. There is nothing to stop anyone building to a higher standard. I know that legal "floors" tend to turn into "ceilings", and I am very much aware of the need for us to set the right standards, but if we turn out to be wrong and it proves to be both practicable and worthwhile for people to build to a higher standard there is nothing in our regulations preventing them from doing so.

    The provision of our regulations which has caused concern is the requirement that the thermal transfer coefficient, or U-value, of the external walls of a dwelling should be 1·0. A Committee representing manufacturers of lightweight aggregate concrete blocks and the Brick Development Association have complained to us and to many hon. Members that this new standard will put them at a grave disadvantage compared with the makers of aerated concrete blocks who are a relatively small sector of the construction materials industry. The two firms mentioned by my hon. Friend the Member for Goole (Dr. Marshall) are both Members of the committee, and I have in the past written to other hon. Members about the problems of Plasmor Limited.

    I do not have time to deal with these arguments in detail, although I hope to do so in correspondence with hon. Members who have written to me. However, I should like to put on record our view that, while we do not doubt that the committee's members will face difficulties—some will find them harder than others—we do not believe that there will be the catastrophe that the committee expects. It is possible for block makers to adapt their products without undue cost and in good time. Many have already done so and it would be possible to find alternative uses for their products in other parts of the structure.

    I should say in passing that there appears to be a widespread belief that from 31st January, the date when the new order took effect, all new housing has to be built to the new standards. This is not so. The end of last month was the deadline after which all plans for new housing submitted for approval would have to comply with the new standard.

    Since in the public sector at least it takes from one to two years to move from the submission of plans to the start of work above foundations, the demand for materials for houses built to the old standard will not suddenly stop. In the private sector the time lag is not so great but it exists.

    I should, however, make clear that it has become apparent from surveys we have made that a large proportion of houses in the public sector are already built with external walls at about the new standards. Most of these walls have the usual one leaf of brick and one of block. Nevertheless, it would certainly not be in the interest of block makers to delay adapting their products. I have with me an example of how it can be done which I can show to my hon. Friend.

    I have no reason to believe that the two firms in my hon. Friend's constituency which produce blocks made of both dense and lightweight aggregates should find it impossible to reduce the density of their products to meet the new requirements, either by adapting their moulds to permit the introduction of cavities into the blocks or by using some of the new aggregates now coming on to the market.

    The Question having been proposed after Ten o'clock on Tuesday evening, and the debate having continued for half an hour, Mr. DEPUTY SPEAKER adjourned the House without Question put, pursuant to the Standing Order.

    Adjourned at three minutes to One o'clock.