2. Subject to the provisions of paragraph 5, the insulation works shall include—
(a)the conversion to double windows of all existing qualifying windows in each room in which there are to be insulation works or, if that is not practicable in the opinion of the responsible authority, the replacement by new double windows of all such existing qualifying windows, and such conversion or replacement shall be in accordance with the specifications set out in paragraph 6;
(b)the provision and installation in each room in which there are to be insulation works, of ventilation as specified in paragraph 3; and
(c)the provision of either—
(i)a second door behind or in front of any external door opening directly into an eligible room—
(A)the shortest horizontal distance between the 2 doors being not less than 150 millimetres, at least one of the doors being weather-stripped, and any glazing in the second door which reaches to less than 1,500 millimetres from the floor having glass of a thickness as set out in Table 1 below; and
(B)the ceiling and walls between the two doors being lined with sound-absorbent material;
or, where in the opinion of the responsible authority it is not practicable to provide a second door—
(ii)a new door in place of the existing qualifying door, the replacement door being a new exterior quality door having a solid core and being not less than 44 millimetres thick, any glazed panel in the door having a minimum thickness as set out in Table 1 below (with the total glazed area not exceeding 50 per centum of the area of the door), the door opening being effectively sealed (including threshold seals), keyholes having covers on both sides, and any letterbox having flaps on both sides with effective seals and positive closers:
provided that a claimant for insulation work who desires to refuse an offer of a second door or a replacement door may do so without prejudicing his right to the carrying out of other insulation work or to a grant.
3. The type of ventilation to be provided and installed pursuant to paragraph 2(b) shall be as follows—
(a)where there is no combustion appliance in the room, or there is one or more room-sealed appliances and no other combustion appliance 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:
provided that this sub-paragraph shall not apply where a combined ventilator system is to be provided and installed under paragraph 4(a)(ii);
(b)where an open fire and no other combustion appliance is in the room either—
(i)3 permanent vents type ‘A’ installed as referred to in sub-paragraph (a); or
(ii)2 permanent vents type ‘A’ installed as referred to in sub-paragraph (a), together with an inlet fan ventilator system; or
(iii)one combined ventilator system and one permanent vent type ‘A’ installed as referred to in sub-paragraph (a);
(c)subject to sub-paragraph (d), where one or more flued-combustion appliances, and no other combustion appliance, is in the room and—
(i)where there is no mechanical ventilation present or to be installed, a permanent vent type ‘A’ or an appropriate number of vents type ‘A’ installed as referred to in sub-paragraph (a), to provide a total effective area of the air path which shall not be less than the effective area in square millimetres calculated on the basis of 550 times H:
provided that the total effective area in square millimetres provided by the vent or vents shall not be less than 3,250, and shall not be less than the cross-sectional area of the flue connection;
(ii)where mechanical ventilation is to be installed, either—
(A)an inlet fan ventilator unit plus air supply duct with external cowl or grille as specified in paragraph 4(a)(i)(A) together with a permanent vent type ‘A’ or an appropriate number of permanent vents type ‘A’ installed as referred to in sub-paragraph (a) 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 on the basis of 550 times H minus 3,250, so however that 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 the flue connection in square millimetres; or
(B)a combined ventilator system as specified in paragraph 4(a)(ii) 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 10 (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 on the basis of 550 times H, a permanent vent type ‘A’ as referred to in sub-paragraph (a), 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;
(d)where a gas fire, other than an open fire, and no other combustion appliance is in the room and such fire has an input rating of less than 7 kilowatts, a combined ventilator system or a permanent vent type ‘A’ or an inlet fan ventilator unit;
(e)where 2 or more open fires and no other combustion appliances are in the room, either—
(i)permanent vents type ‘A’ installed as referred to in sub-paragraph (a) to provide a total effective area of air path of 19,500 square millimetres or 50 per centum of the combined flue areas in square millimetres, whichever is greater; or
(ii)an inlet fan ventilator system and sufficient permanent vents type ‘A’ installed as referred to in sub-paragraph (a) so that the total effective area of air path provided by the permanent vents type ‘A’ shall not be less than 16,250 square millimetres or 50 per centum of the combined flue areas less 3,250, whichever is the greater; or
(iii)a combined ventilator system, and sufficient permanent vents type ‘A’ installed as referred to in sub-paragraph (a), so that the effective area of air path through the combined ventilator system together with the effective air path through any permanent vents shall be 19,500 square millimetres or 50 per centum of the combined flue areas in square millimetres, whichever is greater;
(f)where one or more open fires and one or more flued-combustion appliances are in the room and—
(i)where there is no mechanical ventilation present or to be installed, permanent vents type ‘A’ as appropriate, installed as referred to in sub-paragraph (a), to provide a total effective area of air path which shall not be less than 550 times H plus 50 per centum of the combined areas of the flues of the open fires, in square millimetres;
(ii)where mechanical ventilation is to be installed, either—
(A)an inlet fan ventilator system together with an appropriate number of permanent vents type ‘A’ installed as referred to in sub-paragraph (a), so that the effective area of air path through the inlet fan ventilator together with the effective area of air path through any permanent vents shall not be less than 550 times H plus 50 per centum of the combined areas of the flues of the open fires, in square millimetres; or
(B)a combined ventilator system and permanent vents type ‘A’ installed as referred to in sub-paragraph (a), so that the effective area of air path through the combined ventilator system together with the effective air path through any permanent vents shall be not less than 550 times H plus 50 per centum of the combined areas of the flues of the open fires, in square millimetres:
provided that the appropriate number of vents for the purposes of paragraphs (i) and (ii) shall be determined by the need to ensure that sufficient combustion air ventilation is introduced into the room to secure the safe operation of any combustion appliance in the room;
(g)where there is a gas cooking appliance and no other combustion appliance in a kitchen/diner, ventilation directly to the outside of the dwelling by either—
(i)a mechanical ventilator unit with a permanent vent incorporated; or
(ii)a permanent vent type ‘A’;
(h)where there are one or more other combustion appliances in a kitchen/diner in addition to a gas cooking appliance, the ventilation requirements for those appliances shall apply.
4. In addition to the items referred to in paragraph 3, and subject to the provisions of paragraph 5, the insulation works may include only the following items—
(a)where no inlet fan ventilator system or combined ventilator system is to be provided under paragraph 3, either—
(i)(A)the provision and installation in each room in which there are to be insulation works of one inlet fan ventilator unit of a type conforming to the standards of ventilation and acoustic performance specified in paragraph 8, including the connection of the ventilator unit by wiring of not less than 5 amperes capacity to the nearest convenient point in the existing electric supply circuit or to the electric mains switchboard; and
(B)the provision of an air supply duct with external cowl or grille in accordance with the specifications in paragraph 8, in an external wall of each room in which there are to be insulation works for supplying fresh air to the ventilator unit and the blocking up of any existing air brick, provided that flues and direct inlet ducts to combustion appliances in use shall not be blocked; or
(ii)the provision and installation of a combined ventilator system in accordance with the specifications referred to in paragraph 10;
(b)the blocking at fireplace level, by means of a board of a minimum weight of 10 kilogrammes per square metre adequately sealed around the edges, of chimneys into rooms which have been insulated in accordance with paragraph 3: provided that flues to existing combustion appliances shall not be blocked;
(c)the provision of Venetian blinds between the double windows in a room in which there are to be insulation works which has an aspect falling anywhere within a 270 degrees arc between the bearings of 45 degrees and 315 degrees from true north, subject to the blinds complying with the specifications set out in paragraph 7;
(d)the making good of 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.
5.—(1) Two eligible rooms, without combustion appliances, may be treated as a single room for ventilation purposes if there is an area of permanent opening between them equal to at least one-twentieth of the combined floor areas of the two rooms.
(2) An eligible room may be ventilated though an adjoining room where—
(a)the adjoining room is a conservatory or similar room which has not been insulated; and
(b)there is an opening (which may be capable of being closed) between the eligible room and the adjoining room with an area equal to not less than one-twentieth of the combined floor areas of the two rooms; and
(c)for rapid ventilation there are one or more ventilation openings to the external air in the adjoining room, having a total area equal to at least one-twentieth of the combined floor areas of the two rooms, and with some part of each ventilation opening being at least 1.75 metres above floor level; and
(d)for background ventilation there are ventilation openings to the external air in the adjoining room, and between the two rooms, each opening having a total area of not less than 4,000 square millimetres, and being located so as to avoid undue draughts.
(3) Any combustion appliance should either be room-sealed or the room or space containing it should have a ventilation opening of a type required by paragraph 3. If this opening is to an adjoining room or space then such room or space should have an opening of the same size direct to external air. Ventilation openings should not be located in fire-resisting walls or otherwise breach the requirements of paragraph B3 of Schedule 1 to the Building Regulations 1991(1).
(4) Where a room to be insulated contains only a room-sealed appliance or no combustion appliance, the air path through the ventilator system or the vent 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 combined ventilator system or vent when open to the maximum extent conforms to the standards of ventilation and acoustic performance specified in paragraphs 8 or 9 as appropriate and, whether opened or closed, meets the requirements for electrical and fire safety referred to in paragraph 8(e) or 9(4) as appropriate.
(5) If desired by the claimant, a double-glazed window may be installed in place of the double window required by paragraph 2(a), whether or not the standard of acoustic performance provided by such a double-glazed window is comparable to that provided by the window specified in paragraph 6, but grant shall be payable only up to a maximum of the cost of the work specified in paragraph 6.
(6) The insulation works may consist of, or include, items different from those specified in paragraph 2 where 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 paragraph 2, except where paragraph 5(5) or 6(g) applies.
(7) Where any item or part of any item is provided otherwise than under these Regulations and complies with relevant specifications in this Schedule, it shall not be required to be duplicated as a condition for payment of a grant under these Regulations.
(8) Any installation of glazing in windows or doors shall comply with British Standard recommendations on safety published under reference numbers BS 6262:1982 and BS 6262, part 4: 1994.
(9) Where insulation works consist of or include items described in paragraph 6(g), grant only shall be payable, up to a maximum of the cost of glass specified in paragraph 6(b).