Article 6(1)(c)(c), 6(1)(e) and 7
SCHEDULE 1STANDARDS FOR INSULATION WORKS
Interpretation
1. In this Schedule–
“flued combustion appliance” means an appliance, other than an open fire, designed to be connected to an open flue system, its combustion air being drawn from the room in which it is installed;
“open fire” means a domestic appliance with a permanent front opening which distributes its heat to the room in which it is situated, either by radiation alone, or by radiation and convection and includes both solid fuel appliances and flame effect gas fired appliances;
“room sealed appliance” means an appliance which, when in operation, has the combustion air inlet and the combustion products outlet isolated from the room in which the appliance is fitted.
Items required to be included in insulation works
2. Subject to the provisions of this paragraph and of paragraph 3 below, the insulation works done under this Scheme shall include the replacement by or conversion to double windows of all existing windows in each room in which there are to be insulation works under this Scheme in accordance with the specification in paragraph 5 of this Schedule, and the provision and installation in each room in which there are to be insulation works under this Scheme of–
(1) where there is no combustion appliance in the room or where one or more room sealed appliances and no other combustion appliance is in the room a permanent vent type “A” communicating directly with the external air at the highest level which is reasonably practicable in an external wall of the room conforming to the specifications in paragraph 8(5) of this Schedule, except that this paragraph shall not apply where a combined ventilator system is to be provided and installed under paragraph 4(1)(b) of this Schedule;
(2) where an open fire and no other combustion appliance is in the room:–
(a)three permanent vents type “A” as referred to in paragraph 2(1) above, or
(b)two permanent vents type “A” as referred to in paragraph 2(1) above, together with one inlet fan ventilator unit plus air supply duct with external cowl or grill as specified in paragraph 4(1)(a) of this Schedule and such further ventilation as may be recommended by the Solid Fuel Advisory Service, Davy House, Lion Road, Harrow-on-the-Hill, Middlesex HA1 2EX where the fire operates using solid fuel, or
(c)one combined ventilator system as specified in paragraph 4(1)(b) of this Schedule and one permanent vent type “A” as referred to in paragraph 2(1) above;
(3) where one or more flued combustion appliances, and no other combustion appliance, are present in the room and
(A) where no mechanical ventilation is present or is to be installed, a permanent vent type “A” or an appropriate number of permanent vents type “A” as referred to in paragraph 2(1) above to provide a total effective area which shall not be less than the effective area in square millimetres calculated from 550H (where H is the total output rating in kilowatts of flued combustion appliances present in the room) so however that
(a)the total effective area provided shall be not less than 3,250 square millimetres, and
(b)the total effective area provided in square millimetres shall be not less than the cross-sectional area of flue connection in square millimetres ;
(B) where mechanical ventilation is to be installed, either
(a)an inlet fan ventilator unit plus air supply duct with external cowl or grill as specified in paragraph 4(1)(a) of this Schedule, together with a permanent vent type “A” or an appropriate number of permanent vents type “A” as referred to in paragraph 2(1) above so that the total effective area provided by the permanent vent or vents shall not be less than the effective area in square millimetres calculated from 550H minus 3,250 (where H is the total output rating in kilowatts of flued combustion appliances present in the room) so however that
(i)the total effective area provided by the permanent vent or vents shall not be less than 3,250 square millimetres, and
(ii)the total effective area in square millimetres provided by the permanent vent or vents added to 3,250 shall not be less than the cross-sectional area of flue connection in square millimetres, or
(b)a combined ventilator system as specified in paragraph 4(1)(b) of this Schedule and, where necessary to ensure that the effective area of the air path through the combined ventilator system calculated in accordance with the provisions of paragraph 9 of this Schedule (together with the total effective area provided by any permanent vent or vents) shall not be less than the effective area in square millimetres calculated from 550H (where H is the total output rating in kilowatts of flued combustion appliances present in the room), a permanent vent type “A”, as referred to in paragraph 2(1) above, so however that the total effective area in square millimetres provided by the combined ventilator system and any permanent vent or vents shall not be less than the cross-sectional area of the flue connection in square millimetres;
(4) where more than one open fire, or one or more open fires and one or more flue combustion appliances are present in the room and
(a)where no mechanical ventilation is present or is to be installed, two or more permanent vents type “A”, as appropriate, as referred to in paragraph 2(1) above, so as to introduce combustion air ventilation into the room in sufficient quantity to ensure the safe operation of the combustion appliances, so however that the total effective area provided by the permanent vent or vents shall not be less than 6,500 square millimetres;
(b)where mechanical ventilation is to be installed, either
(i)an inlet fan ventilator unit plus air supply duct with external cowl or grill as specified in paragraph 4(1)(a) of this Schedule, together with a permanent vent type “A” or an appropriate number of permanent vents type “A” as referred to in paragraph 2(1) above, so as to introduce combustion air ventilation into the room in sufficient quantity to ensure the safe operation of the combustion appliances, so however that the total effective area provided by the permanent vent or vents shall not be less than 3,250 square millimetres, or
(ii)a combined ventilator system as specified in paragraph 4(1)(b) of this Schedule, and, where necessary to ensure that combustion air ventilation is introduced into the room in sufficient quantity to ensure the safe operation of the combustion appliances, a permanent vent type “A” or an appropriate number of permanent vents type “A” as referred to in paragraph 2(1) above.
Provided that–
(a)Where a room to be insulated under this Scheme contains only a room sealed appliance or no combustion appliance, the airpath through the ventilator system and the vent type “A” may be made capable of being easily closed by a suitable means readily accessible within the room if in all other respects including standard of construction and installation, the ventilator system and vent type “A” when opened to the maximum extent conform to the standard of ventilation and acoustic performance specified in paragraphs 7 and 8 of this Schedule and, whether opened or closed, meet the requirements for electrical and fire safety referred to in paragraphs 7(5) and 8(4) of this Schedule;
(b)the works may consist of, or include, items different from those specified in this paragraph if the standards of ventilation (including air admitted for the purpose of combustion) and acoustic performance provided by such items are not less than those which would have been provided by items specified in this paragraph;
(c)where any items or part of an item is provided otherwise than under this Scheme and complies with the relevant specifications in this Schedule, it shall not be required to be duplicated as a condition for payment of a grant under this Scheme.
3. Where there is any flued combustion appliance of any output rating in a room to be insulated under this Scheme, a vent or vents may be installed provided that the total effective area provided by an appropriate number of permanent vent type “A” shall be not less than the effective area in square millimetres calculated from 550H-1940 (where H is the total output rating in kilowatts of flued combustion appliances present in the room) so, however, that the total effective area provided shall be not less than 3,250 square millimetres and the total effective area provided in square millimetres added to 1940 shall be not less than the cross-sectional area of the flue connection in square millimetres.
Items permitted to be included in insulation works
4. In addition to the items referred to in paragraph 2 of this Schedule the insulation works done under this scheme may include only the following items:–
(1) where no inlet fan ventilator system or combined ventilator system is to be provided under paragraph 2 of this Schedule, either
(a)(i)the provision and installation in each room in which there are to be insulation works under this Scheme of one inlet fan ventilator unit of a type conforming to the standards of ventilation and acoustic performance specified in paragraph 7 of this Schedule including connecting the ventilator unit by wiring of not less than 5 amps capacity to the nearest convenient point in the existing electric supply circuit or to the electric mains switchboard, and
(ii)the provision of an air supply duct with external cowl or grill in accordance with the specification in paragraph 7 of this Schedule, in an external wall of each room in which there are to be insulation works under this Scheme for supplying fresh air to the ventilator unit and the blocking up of any existing airbrick, provided that flues and direct inlet ducts to combustion appliances in use shall not be blocked; or
(b)the provision and installation of a combined ventilator system in accordance with the specification in paragraph 9 of this Schedule
(2) the provision of a second door behind or in front of any external door opening directly into an insulated room, the shortest horizontal distance between the two doors being not less than 150 millimetres, at least one of the doors being weather-stripped, and the ceiling and walls between the doors being lined with sound absorbent material;
(3) blocking at fireplace level, by means of board of a minimum weight of 10 kilogrammes per square metre adequately sealed round the edges, of chimneys into rooms which have been insulated in accordance with paragraph 2 of this Schedule: provided that flues to existing combustion appliances shall not be blocked;
(4) the provision of Venetian blinds between the double windows in a room insulated under this Scheme which faces in a 270° arc between north-east and north-west such blind being of a size and thermal specification prescribed in paragraph 6 of this Schedule;
(5) making good the existing fabric and decoration (not including curtains) after the installation of double windows, ventilation equipment and second doors, including the adaptation of any existing pelmet and curtain track.
Specification for Windows
5. The existing window shall either be retained and converted to a double window by the installation of a new inner window or be replaced by a new double window, if this is essential, and the following conditions shall be complied with:–
(1) any gaps in the outer window shall be effectively sealed by compressible resilient strip or other means;
(2) the inner window may be framed in wood, metal or plastics, and shall be well fitted into the existing window reveal or planted on the wall face round the reveal, with the junction between the wall and window frame fully sealed by means of mastic packing, cover strips or other equally effective means, and shall be glazed with glass having a thickness of not less than 3 millimetres;
(3) both the outer and inner windows shall be adequately openable for means of escape in case of fire to the extent that the existing outer window allows for this, and for direct ventilation when required; the inner window shall be adequately openable for cleaning purposes but the opening lights of the inner window shall be well sealed round their edges either by compressible resilient strip or by other equally effective means;
(4) if the window is a bay window or bow window, the inner window shall either follow the shape of the outer window or shall be taken straight across the bay or bow, and any projecting surround or window board required to close off the window cavity shall have a weight of not less than 10 kilogrammes per square metre;
(5) at least two reveals of the window opening between the outer and inner window shall be lined with sound absorbent material provided that the works specified in this paragraph in relation to an inner window may include materials other than glass if the standards of acoustic performance provided by such materials are not less than those which would have been provided by the use of glass as specified in paragraph (2) of this Article;
(6) the shortest horizontal distance or, in the case of a bay window or bow window where the inner window is taken straight across the bay or bow, the mean horizontal distance, between the glass of the outer window and the glass of the inner window shall be not less than the distance specified in the second column of Table 1 below in relation to the thickness of glass of the inner window specified in the first column of that Table:
TABLE 1
| Less than 4 mm and not less than 3 mm thick | 200 mm |
| Less than 6 mm and not less than 4 mm thick | 150 mm |
| 6 mm thick or more | 100 mm |
Specification for Venetian blinds
6. Venetian blinds where fitted shall be placed between the panes of double windows, and the following conditions shall be complied with:–
(1) the surface of the slats shall be white or near white;
(2) the ratio of width to spacing of the slats shall be between 1.15: 1 and 1.25: 1;
(3) the blind shall have horizontal slats, capable of being raised or lowered, and the slats shall be adjustable in angle of tilt, the control being either:–
(i)by a single continuous cord operating both the raising and lowering and the tilting mechanisms from one end of the blind box, or
(ii)by controls for the raising and lowering and the tilting mechanisms at either end of the blind box;
(4) the controls specified in paragraph (3) above shall, where practicable, be readily accessible within the room with the windows fully closed;
(5) the opening for control cords shall be sealed or kept to the minimum necessary for smooth operating;
(6) the blind box shall be fitted to the top window reveal or frame head, between the panes of the double windows, the length of the slats shall be between 10 millimetres and 30 millimetres less than the length of the recess at its narrowest point, and the blind shall be capable of extending to the lowest level of the glazing of the outer window.
Specification for inlet fan ventilator systems
7. The ventilator system shall consist of a sound attenuating inlet fan ventilator unit and an air supply duct and cowl or grill; such air supply duct and cowl or grill may be of separate construction from the ventilator unit or integral with it but the following conditions shall be complied with:
(1) the air supply duct and cowl or grill shall be designed to allow the passage of air between the ventilator unit and the external air at all times and shall be so constructed that when installed in a cavity wall exposed to the weather:
(a)the weather resistance of the cavity is retained, and
(b)the external cowl or grill provides protection against the passage of snow, rain and vermin:
(2) the ventilator unit shall consist of a controlled variable-speed inlet fan with sound attenuating duct and cover, shall be fitted with an easily removable and washable air filter on the inlet side of the sound attenuating duct to afford adequate protection for the acoustic lining, and shall be capable of supplying fresh air to the room directly from outside by means of the supply duct and cowl or grill;
(3) the ventilator unit shall be securely fixed to the wall in such a position that the air filter can be easily removed, and the junction between the ventilator unit and the face of the wall shall be fully sealed by means of compressible strip or other equally effective means;
(4) the air supply duct and cowl or grill shall be securely fixed to the wall and the junction between the air supply duct and the internal leaf shall be fully sealed by suitable means;
(5) the ventilator unit shall be electrically safe in operation and maintenance and shall not present a fire hazard;
(6) the ventilator unit with air filter in position, by itself or with an integral air supply duct and cowl or grill, shall be capable of giving variable ventilation rates ranging from:
(a)an upper rate of not less than 37 litres per second against a back pressure of 10 newtons per square metre and not less than 31 litres per second against a back pressure of 30 newtons per square metre, to
(b)a lower rate of between 10 and 17 litres per second against zero back pressure; and if there is no continuous control of the ventilation rate, the following intermediate settings shall be provided:
(i)a ventilation rate of greater than 31 and less than 33 litres per second against a back pressure of 10 newtons per square metre, and
(ii)a ventilation rate of greater than 21 and less than 26 litres per second against a back pressure of 10 newtons per square metre;
(7) the effective area of the air path through the ventilator system with the fan switched off and the air filter in position shall be not less than 3,250 square millimetres and the said area shall be ascertained by measuring the static pressure difference across the ventilator system for various air flow rates through the ventilator system and calculating the effective area from
(where Q is the measured air flow rate through the ventilator system in litres per second and Δρ the measured static pressure difference across the ventilator system in newtons per square metre): effective areas shall be calculated for air flow through the ventilator system in both directions and the lower calculated value shall be taken for the effective area;
(8) the ventilator unit by itself or integral with the air supply duct and cowl or grill shall be so constructed that
(a)when it is in operation in any room the sound level in the room due to the operating of the unit at a ventilation rate of 31 litres per second against a back pressure of 10 newtons per square metre, measured at any point not nearer than 1 metre to the unit or any of the room surfaces and normalised by the subtraction of
10log.1010A
(where A is the measured sound absorption in the room in square metre units at each ½-octave frequency interval from 100 to 3,150 Hz) does not exceed 35 decibels on the A scale and at the maximum ventilation rate of the unit does not exceed 40 decibels on the A scale against a back pressure of 30 newtons per square metre; and
(b)the sound pressure level difference (measured in accordance with British Standard methods for the measurement of sound insulation in buildings and of building elements published under the number B.S. 2750 Part 3: 1980) between two rooms separated by a solid wall of area not less than 10 square metres and of average mass (calculated over any portion of the wall measuring 1 square metre) of not less than 415 kilogrammes per square metre incorporating the ventilator unit normalised by the addition of
10log.1010A
(where A is the measured sound absorption in the receiving room in A square metre units at each "-octave frequency), is not less than the figure shown in Table 2 below except for total adverse deviations (at all "-octave frequencies) not exceeding 32 decibels and an adverse deviation at any one ½-octave frequency not exceeding 8 decibels.
TABLE 2
| ½-octave frequency band centre (Hertz) | Normalised sound pressure level difference (Decibels) |
|---|---|
| 100 | 30 |
| 125 | 33 |
| 160 | 36 |
| 200 | 39 |
| 250 | 42 |
| 315 | 45 |
| 400 | 48 |
| 500 | 49 |
| 630 | 50 |
| 800 | 51 |
| 1,000 | 52 |
| 1,250 | 53 |
| 1,600 | 53 |
| 2,000 | 53 |
| 2,500 | 53 |
| 3.150 | 53 |
Specification for permanent vents
8.—(1) Every permanent vent type “A” shall consist of a sound attenuating purpose-made opening or duct which is designed to allow the passage of air between the room and the external air at all times, and shall have an external cowl or grill for protection against the passage of snow, rain and vermin. It shall be so constructed that when installed in a cavity wall exposed to the weather the weather resistance of the cavity is retained and the acoustic performance of the vent is protected.
(2) The effective area of the air path through the permanant vent shall be ascertained by the method set forth in paragraph 7(7) above, save that for the words “ventilator system” there shall be stubsituted “permanent vent”.
(3) When installed the permanent vent shall be securely fixed to the wall and the junction between the vent and the face of the wall shall be fully sealed by means of compressible strip mastic packing, cover strips or other equally effective means, and where the vent has an air supply duct traversing a cavity wall the junction between the supply duct and the internal leaf shall be fully sealed by suitable means to prevent the passage of air to or from the cavity.
(4) Vents shall be so constructed and installed as not to present a fire hazard.
(5) every permanent vent type “A” shall:
(a)have an effective area, calculated in accordance with paragraph (2) above, of not less than 3.250 square millimetres, and
(b)be so constructed that the sound pressure level difference ascertained by the method set forth in paragraph 7(8)(b) above, complied with the requirements therein set forth, save that for the words “ventilator unit” there shall be substituted “vent”.
Specification for combined ventilator system
9. The combined ventilator system shall conform to the design and standards of ventilation and acoustic performance specified in paragraph 2(1), 4(1)(a), 7 and 8 of this Schedule except that the requirement on paragraph 2(1) that the installation be made at the highest level which is reasonably practicable shall not apply.