1. The intention of this Part is to ensure that measures are taken to protect people, and the fabric of a building, from harm which could be caused by site conditions or the effects of moisture in various forms.
2. In addition to surface soil and decaying or organic matter being removed from a site, thorough investigation is necessary to ensure that appropriate measures can be taken where there is evidence of any harmful or dangerous substances. An Appendix giving outline guidance is included at the end of this Part.
3. Subsoil drainage of the site is required where necessary to help prevent the penetration of ground water and flood water to the interior of a building and damage to the building fabric. Any existing drains which will be affected by the construction of a building must also continue to function properly.
4. A building must be constructed so that moisture in the ground and from the weather will not damage the fabric or penetrate to the inner surface of the building.
5. For the control of condensation in roofs the deemed-to-satisfy specification quotes BS5250 which provides guidance on the principal forms of construction including cold deck roofs. There is evidence which suggests that condensation in this type of roof system is a problem. The Scottish Executive considers that in the climatic conditions of Scotland ventilation of the roof void in flat roofs should not be endorsed as many instances of failure in cold deck roof systems have been recorded. Both the warm deck and warm deck inverted roof constructions, where the insulation is placed above the roof deck, are considered preferable. While the Regulations do not prevent the use of cold deck roof constructions, it is considered that much more reliable forms of construction are likely to result from over-roof insulation whenever this is possible.
6. A building of purpose group 1, a dwelling (ie a house, flat or maisonette) must be constructed to reduce the risk of both interstitial and surface condensation in order to prevent damage to the fabric and harmful effects on the health of people using the building. The requirements for both interstitial and surface condensation are deemed to be satisfied by the guidance given in BS5250: 1989 "British Standard Code of Practice for the Control of condensation in buildings". However, the guidance in BS5250, which covers buildings generally, should be followed for other buildings where the internal climate is quite stable.
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Preparation of sites |
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16. |
(1) Subject to paragraph (3), a site and ground immediately adjoining a site shall be so pre-pared and treated as to protect the building and its users from harmful effects caused by - |
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(2) Subject to paragraph (3), a site and ground immediately adjoining a site shall be so drained or otherwise treated as to protect the building and its users, so far as may be reasonably practicable, from harmful effects caused by - |
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(3) Paragraphs (1)(b), (1)(c) and (2)(c) shall not apply to a limited-life building of purpose groups 2 to 7 inclusive. |
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(4) In paragraph (1)(a) "harmful or dangerous substances" includes deposits of faecal or animal matter and any substance or mixture of substances which is or could become corrosive, explosive, flammable, radioactive or toxic or which produces or could produce any gas likely to have any such characteristic. |
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Resistance to moisture |
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17. |
(1) Subject to paragraph (2), a building shall be so constructed as to protect the building and its users from harmful effects caused by - |
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(2) This regulation shall not apply to a building where penetration of moisture from outside will result in effects no more harmful than those likely to arise from use of the building. |
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Resistance to condensation |
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18. |
A building of purpose group 1 shall be so constructed as to protect the building and its users, so far as may be reasonably practicable, from harmful effects caused by condensation. |