§ Sir David Priceasked the Secretary of State for the Environment if he will list in the Official Report his estimate of the number of houses in each category of prefabricated concrete houses and identify which categories are known to have serious structural defects and which have not.
§ Mr. GowIn my statement to the House on 10 November 1983 at column 422 I explained that the Building Research Establishment (BRE) had found
- (a) that the reinforced concrete components in 6 of the most common types of prefabricated reinforced concrete houses were gradually deteriorating as a result of carbonation of the concrete and, in some cases, the presence of high levels of chlorides, leading to corrosion of the steel reinforcement and consequent cracking of the concrete, and
- (b) that the processes of carbonation and attack by chlorides were likely to affect all prefabricated reinforced concrete houses built before 1960.
At the same time I placed in the Library a table giving figures of the number of each type of prefabricated concrete house built before 1960 in each local authority area, amounting to some 140,000 in England. These figures were based on special returns made by authorities in 1982. I told the House that the BRE's earlier findings had been confirmed by further studies when I introduced the Second Reading of the Housing Defects Bill on 26 9W April 1984 at column 896. I also gave the names of the 28 types which we intended to designate under the Bill at that time.
I emphasise that these findings do not apply to other types of houses or flats constructed by non-traditional methods and I have no plans to designate other such types under the Housing Defects Act. Nor does my Department have detailed information about their numbers. However we estimate that there are some 200,000 dwellings built as part of the industrialised housing drive during the 1960s and 1970s which can broadly be described as of prefabricated reinforced concrete construction. Of these some 30,000 were houses and the remainder flats. Although certain defects have been found in some buildings within this category, there is no evidence that any type suffers from a universal inherent defect. I have advised owners of Bison Wallframe and Taylor Woodrow Anglian buildings to carry out particular checks and to take action where this is appropriate.