Certain small buildings and extensions are exempt from Building Control it is therefore advisable to check before making a Building Regulations application.
The criteria for exempt buildings is set down by class on Schedule 2 of the Building Regulations 2014, which are as follows:
Class 1 - Buildings not frequented by people
A detached building:
- Into which people do not normally go, or
- Into which people go only intermittently and then only for the purpose of inspecting or maintaining fixed plant or machinery.
Unless any point of such a building is less than one-and-a-half-times its height from:
- Any point of a building into which people can or do normally go, or
- The nearest point of the boundary of the curtilage of that building
whichever is the nearer.
Class 2 - Greenhouses and agricultural buildings
1. Subject to paragraph 3, a greenhouse.
2. A building used, subject to paragraph 3, for agriculture, or a building principally for the keeping of animals, if:-
(a) No part of the building is used as a dwelling
(b) No point of the building is less than one-and-a-half-times its height from any point of a building which contains sleeping accommodation, and
(c) The building is provided with a fire exit which is not more than 30 metres from any point in the building.
3. The descriptions of buildings in paragraphs 1 and 2 do not include a greenhouse or a building used for agriculture if the principal purpose for which they are used is retailing, packing or exhibiting.
4. In paragraph 2, agriculture includes horticulture, fruit growing, the growing of plants for seed and fish farming.
Class 3 - Temporary buildings
A building which is not intended to remain where it is erected for more than 28 days and is not re-erected on the same site within the next 12 months.
Class 4 - Ancillary buildings
1. A building on a site, being a building which is intended to be used only in connection with the disposal of building or building plots on that site.
2. A building on the site of construction or civil engineering works, which is intended to be used only during the course of those works and contains no sleeping accommodation.
3. A building, other than a building containing a dwelling or used as an office or showroom, erected for use on the site of and in connection with a mine or quarry.
Class 5 - Small detached buildings
A detached single storey building, having a floor area which does not exceed 30 square metres, which contains no sleeping accommodation and is a building:
(a) No point of which is less than 1 metre from the boundary of its curtilage; or
(b) Which is constructed substantially of non-combustible material.
A detached building designed and intended to shelter people from the effects of nuclear, chemical or conventional weapons, and not used for any other purpose, if:
(a) Its floor area does not exceed 30 square metres; and
(b) The excavation for the building is no closer to any exposed part of another building or structure than a distance equal to the depth of the excavation plus 1 metre.
3. A detached building, having a floor area which does not exceed 15 square metres, which is not heated, contains no sleeping accommodation and is a building
- a) No point of which is less than 1m from the boundary of its curtilage; or
- b) Which is constructed substantially of non-combustible material.
Class 6 - Extensions
The extension of a dwelling by the addition at ground level of:
(a) the structure is
i) A conservatory, sun room, porch, covered yard or covered way, or covered way with a floor area not exceeding 15m2; or
ii) A car port open on at least two sides with a floor area not exceeding 30m2;
(b) In the case of a conservatory, sun room or porch which is wholly or partly glazed, the glazing satisfies the requirements of Part L1 and Part N of Schedule 1;
(c) No point of the structure is less than 1m from the boundary of its curtilage;
(d) The maximum span of roof members between end supports does not exceed 4m; and
(e) Access to the roof is for the purpose of maintenance and repairs only.
Proposed building work which involves building over or within 3 metres of public sewer or private drainage serving more than 1 building is not exempt from these regulations.
Class 7 - Alterations
Replacement of -
(a) a window, roof light, roof window or door provided
i) any windows, roof window or roof light have a window energy rating (WER) Band C or better or U value 1.6 W/m2k
ii) any doors with up to 50% of internal face glazed have a U value of 1.8 W/m2k;
iii) other doors have a U value of 1.8 W/m2k; and
iv) any windows, doors comply with the requirements of Part S, Schedule 1; or
(b) a space heating or hot water service boiler or a hot water vessel, provided that it satisfies the requirement of Part L of Schedule 1 in connection with an existing dwelling.
(c) An existing window in a dwelling house with new patio or French doors, provided –
i) No works may be undertaken except at ground floor level
ii) Any new patio or French doors must only utilise an existing width; and
iii) The works must comply with the requirements of Part S, Schedule 1.
For comprehensive advice on exemptions and what requires Building Regulations approval, contact the Department of Environment, Food and Agriculture's Building Control Section, or the 2 other building authorities on the Isle of Man.