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LEGAL ACTS OF THE REPUBLIC OF LATVIA
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Republic of Latvia

Cabinet
Regulation No. 280
Adopted 25 June 2019

Regulations Regarding the Latvian Construction Standard LBN 002-19, Thermotechnics of Building Envelopes

Issued pursuant to
Section 5, Paragraph one, Clause 3 of the Construction Law

1. The Regulation approves the Latvian Construction Standard LBN 002-19, Thermotechnics of Building Envelopes (hereinafter - the Construction Standard).

2. Cabinet Regulation No. 339 of 30 June 2015, Regulations Regarding the Latvian Construction Standard LBN 002-15, Thermotechnics of Building Envelopes (Latvijas Vēstnesis, 2015, No. 125), is repealed.

3. Building designs which have been drawn up according to specific procedures and coordinated until the day of coming into force of this Regulation need not be remade according to the requirements laid down in the Construction Standard.

4. The Regulation shall come into force on 1 January 2020.

Informative Reference to the European Union Directive

This Regulation contains legal norms arising from Directive 2010/31/EU of the European Parliament and of the Council of 19 May 2010 on energy performance of buildings.

Prime Minister A. K. Kariņš

Minister for Economics R. Nemiro

 

Approved by
Cabinet Regulation No. 280
25 June 2019

Latvian Construction Standard LBN 002-19, Thermotechnics of Building Envelopes

I. General Provisions

1. The Construction Standard prescribes:

1.1. the procedures for the energy efficiency design of the structure elements of external building envelopes and their connections for heated buildings to be newly erected, rebuilt, and renewed, and also for new heated premises to be installed in already built buildings the temperature in which during the heating season is maintained at 8 °C and higher;

1.2. the thermotechnical parameters to be used in the calculations during the designing of heating, ventilation, and systems.

2. The purpose of the Construction Standard is to reduce energy consumption in buildings by increasing the efficiency of energy use and to prevent the formation of structural-physical defects in buildings and their structure elements. Energy efficient structure elements limiting carbon dioxide emissions shall be provided for in the construction of buildings.

3. Envelopes or elements of buildings (hereinafter - the structure element) are the external walls, roofs, garret floors, coverings which are in contact with the outdoor air (also over passages), floors on unheated cellars, cold cellars and floor on the ground, external walls of a cellar which are in contact with the outdoor air or ground, windows in the external walls, doors and gates, and also internal walls and other surfaces, if they delimit premises the temperature margin between which is 5 °C and more. Such structure elements and their solutions are energy efficient which provide sufficiently efficient protection of the room from cooling during the winter and from overheating during the summer, ensuring a better thermal comfort indoors. Thermal inertia shall be assessed for the structure elements and the most appropriate combination of load bearing and thermal insulating layers shall be selected.

4. In projects which are co-financed by the European Union, the State, or the local government, the solutions for the designs of rendered façades of external walls and the solutions for the designs of ventilated façades shall be drawn up in accordance with European Technical Approvals issued on the basis on the European Technical Approval Guidelines for External Thermal Insulation Composite Systems ETAG 004.

5. The Construction Standard shall not be applied to the buildings referred to in Section 3, Paragraph two, Clause 2 of the Energy Efficiency Law.

6. A specific micro-climate of high energy intensity shall be ensured for buildings and premises (for example, for freezing rooms, climate chambers), providing for energy efficient structure elements, and the technically and economically most appropriate solution shall be ensured in the application of this Construction Standard, in addition also ensuring high efficiency of energy use for it.

7. Upon performing the thermotechnical calculation and designing of the structure elements, the standards referred to in this Construction Standard shall be applied. Application of an alternative methodology for calculation shall be permitted if the result of the technical execution thereof is not worse than that laid down in the standard and it ensures conformity with the essential requirements to be brought forward for the structure laid down in the Construction Law.

II. Energy Efficiency Requirements

8. Energy efficiency of the buildings to be newly erected shall conform to the threshold values indicated in Table 1 of Annex to this Construction Standard. Calculation of energy consumption shall be performed in accordance with Cabinet regulations regarding the methodology for calculating the energy efficiency of buildings.

9. Energy efficiency of the buildings to be renewed or rebuilt shall conform to the threshold values indicated in Table 2 of Annex to this Construction Standard. Calculation of energy consumption shall be performed in accordance with Cabinet regulations regarding the methodology for calculating the energy efficiency of buildings.

10. If the average height of the building for premises to be heated is more than 3.5 metres, the minimum permissible level of energy efficiency of the buildings may exceed the indicators referred to in Paragraphs 8 and 9 of this Construction Standard. Taking into account the average height of the building for premises to be heated, the minimum permissible level of energy efficiency of the buildings shall be calculated, using the following formula:

Emin.apr. = Emin × h where (1)
3.5

Emin.apr. - minimum permissible level of energy efficiency of the buildings, if the average height of the building for premises to be heated exceeds 3.5 metres (kWh/m2 per year). If the re-calculated minimum permissible level of energy efficiency of the buildings for a building to be newly erected exceeds 90 kWh/m2 per year, the minimum permissible level of energy efficiency of the buildings for a building to be newly erected shall be 90 kWh/m2 per year. If the re-calculated minimum permissible level of energy efficiency of the buildings for renewal or rebuilding exceeds 120 kWh/m2 per year, the minimum permissible level of energy efficiency of the buildings for renewal or rebuilding shall be 120 kWh/m2 per year;

h - actual average height of the building for premises to be heated (m);

Emin - the minimum permissible level of energy efficiency of the buildings in accordance with Paragraph 9 or 10 of this Construction Standard (kWh/m2 per year).

11. The values Ui and ψj of the calculated heat transmittance coefficients of individual structure elements and linear thermal bridges shall not exceed the maximum values URM and ψRM specified in Table 3 of Annex to this Construction Standard, URM shall be the maximum heat transmittance coefficient W/(m2 × K) of the relevant structure element, whereas ψRM - the maximum heat transmittance coefficient of the relevant linear thermal bridge W/(m × K). The maximum values URM for floors which are in contact with the outdoor air shall be the same as for roofs.

12. If renewal or rebuilding affects less than 25 % of the total surface area of the structure elements of the building, the requirements referred to in Paragraph 9 of this Construction Standard need not be applied.

13. The temperature in unheated adjacent premises shall be determined in accordance with the standard LVS EN ISO 13789:2017, Thermal performance of buildings - Transmission and ventilation heat transfer coefficients - Calculation method (ISO 13789:2017).

III. Calculated Values of Construction Products and Structure Elements

14. The values of the calculated heat transmittance coefficients Ui, ψj, and χk shall be determined for:

14.1. walls, roofs, and floors which are in contact with the outdoor air - in accordance with the standard LVS EN ISO 6946:2017, Building components and building elements - Thermal resistance and thermal transmittance - Calculation methods (ISO 6946:2017);

14.2. floors lacking contact with the outdoor air - in accordance with the standard LVS EN ISO 13370:2017, Thermal performance of buildings - Heat transfer via the ground - Calculation methods (ISO 13370:2017);

14.3. windows and doors - in accordance with the standard LVS EN ISO 10077-1:2017, Thermal performance of windows, doors and shutters - Calculation of thermal transmittance - Part 1: General (ISO 10077-1:2017), and LVS EN ISO 10077-2:2017, Thermal performance of windows, doors and shutters - Calculation of thermal transmittance - Part 2: Numerical method for frames (ISO 10077-2:2017);

14.4. thermal bridges ψj and χk − in accordance with the standard LVS EN ISO 10211:2017, Thermal bridges in building construction - Heat flows and surface temperatures - Detailed calculations, or LVS ISO 14683:2017, Thermal bridges in building construction - Linear thermal transmittance - Simplified methods and default values (ISO 14683:2017). For the determination of the heat transmittance coefficients of thermal bridges ψj and χk such catalogues of thermal bridges may be used in which the values of thermal bridges have been determined, using the calculation conditions of the standard LVS EN ISO 10211:2017, Thermal bridges in building construction - Heat flows and surface temperatures - Detailed calculations (ISO 10211:2017), and the calculation conditions of which correspond to the situation to be designed;

14.5. point thermal bridges χk if they present a risk of condensate - by assessing as an additional attenuation in structures. The necessary calculations and threshold values shall be determined in accordance with LVS EN ISO 13788:2013, Hygrothermal performance of building components and building elements - Internal surface temperature to avoid critical surface humidity and interstitial condensation - Calculation methods (ISO 13788:2012).

15. Thermal bridge ψj (W/mK) is any formation in the construction of a building where the heat transmission of homogeneous envelopes is changed by the following factors:

15.1. the envelope or a part thereof is crossed by materials with different thermal conductivity;

15.2. the thickness of materials changes;

15.3. there is a difference between the external and internal dimensions of the structure element;

15.4. other factors affecting heat losses in local areas.

16. The conformity of the heat transmittance coefficient of a thermal bridge with the values defined in this Construction Standard shall be assessed according to the external dimensions of the structure element. The relative critical surface humidity at sites of the thermal bridge shall be inspected in accordance with the methodology for calculation defined in the standard LVS EN ISO 13788:2013, Hygrothermal performance of building components and building elements - Internal surface temperature to avoid critical surface humidity and interstitial condensation - Calculation methods (ISO 13788:2012), and the permissible threshold values. Upon determining the relative critical surface humidity, the calculation shall be performed provided that the temperature of external air is Θe (-5°C).

17. The calculated heat transmittance coefficient Ui for industrially manufactured structure elements in the regulated field shall be certified in a conformity assessment process in accordance with Regulation (EU) No 305/2011 of the European Parliament and of the Council of 9 March 2011 laying down harmonised conditions for the marketing of construction products and repealing Council Directive 89/106/EEC (hereinafter - Regulation No 305/2011).

18. For the construction products the main function of which in the structure element is not thermal insulation and the thermotechnical properties thereof are not certified during the conformity assessment process, the values of the calculated heat transmittance and other thermotechnical characteristics shall be determined in accordance with Table 10 of Annex to this Construction Standard.

19. The measurements of the actual values of the calculated heat transmittance coefficient Ui of the structure elements shall be taken in conformity with the standard LVS EN ISO 8990:2007 L, Thermal insulation - Determination of steady-state thermal transmission properties - Calibrated and guarded hot box.

IV. Air Permeability and Energy Efficiency Indicators of Buildings

20. Air permeability of a structure is a structural and physical value characterising the construction quality of the building and ensures a possibility for efficient control of micro-climate in the building and for ensuring of the energy efficiency requirements.

21. Air permeability of the entire building, expressed as an air leak m3/(m2 × h) and measured with the pressure margin 50 Pa (q50), may not exceed the threshold values determined in Paragraph 22 of this Construction Standard.

22. Depending on the method of ventilation of the relevant building, the following threshold values shall be determined for residential houses, homes for the elderly, hospitals, kindergartens, and public buildings:

22.1. for buildings with natural ventilation (airing) - q50 ≤ 3 m3/(m2 × h);

22.2. for buildings with a mechanical ventilation system - q50 ≤ 2 m3/(m2 × h);

22.3. for buildings with a mechanical ventilation system which is equipped with heat recovery (air recuperation) devices - q50 ≤ 1.5 m3/(m2 × h);

22.4. for production buildings - q50 ≤ 4 m3/(m2 × h).

23. The requirements referred to in Paragraph 22 of this Construction Standard shall also be taken into account in relation to the connections and assembly seams of the structure element.

24. Air permeability of buildings shall be determined in accordance with the standard LVS EN 9972:2016, Thermal performance of buildings - Determination of air permeability of buildings - Fan pressurization method (ISO 9972:2016). For the performance of the test, the building shall be prepared according to the Method 2 of the abovementioned standard - by closing all the windows, doors, hatches in the building.

V. Water Vapour Permeability of Structure Elements

25. If the structure element, its connections and assembly seams consist of different layers, the total equivalent of air diffusion of water vapour resistance sd of the layers on the warm side thereof shall be at least five times greater than the total equivalent of air diffusion of water vapour resistance sd of the layers adjacent to the cold side. The sd values for most commonly utilised membrane materials are determined in Table 4 of Annex to this Construction Standard.

26. The water vapour resistance of construction products shall be determined, using the following formula:

where (2)

sd - the equivalent of air diffusion of water vapour resistance of construction products (m);

µ - the water vapour resistance factor;

d - the thickness (m) of the layer of the homogeneous construction product.

27. The structure element shall be designed and constructed in a way that:

27.1. the balance of accumulation of humidity in the structure element within a year is not positive;

27.2. the drying reserve of humidity for the structure elements of the external wall within a year is at least 100 g/m2, for the structure elements of the roof - at least 200 g/m2;

27.3. the maximum possible quantity of absorbed water of layer materials of the structure element is not exceeded;

27.4. the quantity of the water vapour condensate does not exceed 400 g/m2 on surfaces not absorbing humidity in order to preclude trickling of water drops;

27.5. the total quantity of condensate during the annual heating season does not exceed 1 kg/m2;

27.6. the quantity of humidity for timber in overall increases by not more than 5 % of their mass, for materials containing wood the quantity of humidity increases by not more than 3 % of their mass;

27.7. upon assessing the long-term safety of humidity damages of the structure element, the assessment includes the quantity of layer humidity of the structure elements, and also the transfer of humidity caused by air permeability of the building in the structure element.

28. The technical solution for the fulfilment of the requirements referred to in Paragraph 25 or 27 of this Construction Standard for the structure element, its connections and assembly seams shall be indicated to the same extent and in the same content as to be able to assess conformity with the requirements laid down.

29. Derogations from the requirements referred to in Paragraph 25 of this Construction Standard shall be permissible if conformity with the requirements referred to in Paragraph 27 of this Construction Standard is ensured.

30. If an air gap between the thermal insulation or wind barrier next to it and the external finish is required to fulfil the requirements referred to in Paragraph 25 or 27 of this Construction Standard, it must be possible to ventilate the thermal insulation. Such thermal insulation is considered ventilated the air separating layer of which is in contact with the outdoor air and the air flow conditions conform to the criteria specified in the standard LVS EN ISO 6946:2017, Building components and building elements - Thermal resistance and thermal transmittance - Calculation methods (ISO 6946:2017). The air separating layer is ventilated, if the following conditions are met:

30.1. the cross-sectional area of ventilation apertures is not smaller than 15 cm2 per each metre of the length of a vertical air separating layer (along the perimeter of the building);

30.2. the cross-sectional area of ventilation apertures is not smaller than 15 cm2 per each square metre of the surface of the envelope for a horizontal air separating layer.

31. The value sd for glass, ceramic tiles, metals, and metal sheets shall be unlimited. The value 106 m shall be used in the calculations.

32. In respect of hermetic multilayer panels covered on both sides by metal sheets with a thermal insulation layer between them, the requirement referred to in Paragraph 25 of this Construction Standard shall apply to the junctures of the panels which are on the warm and cold sides of the thermal insulation.

VI. Thermotechnical Characteristics of Construction Products

33. Upon performing engineering calculations, the information provided by the manufacturer shall be primarily selected as the output data. If such information is not available, it shall be permitted to use studies, the literature of the field, or Annex to this Construction Standard. Upon selecting the data provided by the manufacturer regarding thermal conductivity of materials, it shall be ascertained that it has been checked in accordance with the methodology referred to in Paragraph 36 of this Construction Standard. The declared thermal conductivity λD shall be used for the performance of calculations.

34. The manufacturer shall indicate in the declaration of conformity the declared thermal conductivity λD W/(m × K) for each type of thermal insulation product according to the technical provisions.

35. A class of thermal conductivity shall be determined for all thermal insulating products. The class of thermal insulating product shall be the guaranteed declared thermal conductivity thereof which is expressed in W/(m × K) (Watts per meter and degree) and rounded up to the highest closest class indicator. The manufacturer shall indicate the class of the thermal insulating material according to the technical provisions of the construction product.

36. The declared coefficient of thermal conductivity λD or the declared thermal resistance RD of the thermal insulating material shall be determined in accordance with the standard LVS EN ISO 10456+AC:2013 L, Building materials and products - Hygrothermal properties - Tabulated design values and procedures for determining declared and design thermal values.

37. Conversion of thermal values shall be performed in accordance with the standard LVS EN ISO 10456+AC:2013 L, Building materials and products - Hygrothermal properties - Tabulated design values and procedures for determining declared and design thermal values.

38. Upon determining the calculated heat transmittance value Ui and the thickness of the thermal insulation layer for the structure element, the shrinkage of the bulk thermal insulating material during the lifetime thereof shall be taken into consideration. The extent of shrinkage for glass wool and rock wool shall not be less than 5 %, but for cellulose-based fibres - not less than 20 %.

39. If the measurements of the thermal conductivity are taken according to the harmonised technical provisions for construction products or using matured (aged) materials, the correction factor Dla may be zero.

40. The declared thermal conductivity λD W/(m × K) shall be determined according to the harmonised technical provisions for construction products or using the following formula (if there are no harmonised technical provisions for the relevant thermal insulating material or the way of determination of the declared thermal conductivity is not referred to in the harmonised technical provisions):

where (3)

λ10m - the thermal conductivity value of the thermal insulating material at the average temperature of 10 °C in accordance with Paragraph 28 or 38 of this Construction Standard;

Δλs - the correction factor for the evaluated standard deviation in accordance with Paragraph 27 of this Construction Standard;

Δλa - the correction factor for ageing.

41. If thermal insulating materials which are manufactured in accordance with the harmonised European standards and which have been labelled with the CE mark, and have a declared product thermal resistance of RD (m2K/W), the thermal conductivity class of such products shall be determined in accordance with formula (4) and the acquired value shall be rounded up to the closest value with accuracy up to 0.001 W/(m × K):

where (4)

dN - the nominal thickness of the thermal insulating material in accordance with the relevant harmonised European standard. In such case the manufacturer shall indicate the declared thermal conductivity λD or the declared thermal resistance of the construction product RD on the packaging, without indicating the thermal conductivity class with a separate mark.

42. The calculated thermal conductivity λD W/(m × K) of a thermal insulating material, taking into consideration the envelopes in actual working conditions, shall be determined in accordance with the standard LVS EN ISO 6946:2017, Building components and building elements - Thermal resistance and thermal transmittance - Calculation methods (ISO 6946:2017), or by using formula (5), adding the adjustment-for-working-conditions coefficient Δλw to the result obtained in accordance with Table 4 of Annex to this Construction Standard unless specified otherwise in the harmonised standard for a construction product:

(5)

43. The calculated thermal conductivity of the thermal insulating material for the structure element to be indicated in the documentation of the construction intention shall be determined in accordance with Paragraph 42 of this Construction Standard.

44. The values Δλw of the adjustment coefficient for the thermal insulating materials most frequently used in the structure elements are specified in Table 5 of Annex to this Construction Standard.

45. The values of the correction coefficient Δλwspecified in Table 6 of Annex to this Construction Standard shall apply to thermal insulating materials which are used on the ground, in the external walls of a cellar, under the floor on the ground or outside horizontally as a protection measure against frost heave of the soil. If the density of the thermal insulating material conforms to the range indicated in the abovementioned table, the values of the correction coefficient Δλw shall be determined by means of a linear interpolation. If the density of the thermal insulating material does not conform to the range referred to in the table, the use thereof in such manner is not permitted.

46. The values of the correction coefficient Δλw for inverted roof constructions for the thermal insulation of which extruded expanded polystyrene (XPS) or grooved sheets thereof covered with a straining cloth have been applied shall be specified in Table 7 of Annex to this Construction Standard. An inverted roof shall be such a roof in which the thermal insulation layer is laid over the waterproofing layer.

47. The calculated thermal conductivity shall be used upon determining the value of the calculated thermal conductivity coefficient Ui of the structure element.

48. The calculated thermal conductivity λd for construction products to be used in a regulated field the conformity of which has not been certified as for thermal insulating materials in accordance with Regulation No 305/2011 shall be determined in accordance with Table 10 of Annex to this Construction Standard.

VII. Thermal Inertia of Structure Elements

49. Thermal inertia shall depend on thermal mass of the structures of a building. Thermal mass is a function from the density of the material (ρ, kg/m3) and the specific heat capacity cp (kJ/(kgK)) and is the indicator of heat resistance.

50. The thermal inertia of the structure element shall be calculated in accordance with the standard LVS EN ISO 52016-1:2017, Energy performance of buildings - Energy needs for heating and cooling, internal temperatures and sensible and latent heat loads - Part 1: Calculation procedures (ISO 52016-1:2017).

51. The dimensions λ, ρ, and c for some construction products are indicated in accordance with Paragraph 39 of this Construction Standard and also are indicated in Tables 9 and 10 of Annex to this Construction Standard. The humidity of some construction products for the calculations of thermal inertia in percentage is specified in Table 7 of Annex to this Construction Standard. For thermal insulating materials the calculated thermal conductivity λ d of which is determined in accordance with this Construction Standard, in calculations of inertia = λ. d.

Minister for Economics R. Nemiro

 

Annex
to Latvian Construction Standard LBN 002-19,
Thermotechnics of Building Envelopes
(approved by Cabinet Regulation No. 280
of 25 June 2019)

Indicators of Thermotechnics of Building Envelopes and Their Values

Table 1

Minimum Permissible Level of Energy Efficiency of Buildings for Newly Erected Buildings1

No.

Acceptance period of the documentation of the construction intention of the building

Minimum permissible level of energy efficiency of buildings, energy efficiency assessment for heating of newly erected buildings

for residential buildings

for non-residential buildings
(the types of buildings referred to in Sub-paragraphs 6.1.3, 6.1.4, 6.1.5, 6.1.6, 6.1.7, 6.1.8, and 6.1.9 of the Regulation2)

multi-apartment buildings

one-apartment or two-apartment buildings

buildings which are in the ownership of the State or local government and in the possession of the authorities and where the State or local government authorities are located

other non-residential buildings

1.

Until 31 December 2016 ≤ 70 kWh/m2 per year ≤ 80 kWh/m2 per year ≤ 100 kWh/m2 per year ≤ 100 kWh/m2 per year

2.

From 1 January 2017 to 31 December 2017 ≤ 60 kWh/m2 per year ≤ 70 kWh/m2 per year ≤ 90 kWh/m2 per year ≤ 90 kWh/m2 per year

3.

From 1 January 2018 to 31 December 2018 ≤ 60 kWh/m2 per year ≤ 70 kWh/m2 per year ≤ 65 kWh/m2 per year ≤ 90 kWh/m2 per year

4.

From 1 January 2019 to 31 December 2020 ≤ 50 kWh/m2 per year ≤ 60 kWh/m2 per year nearly zero-energy building ≤ 65 kWh/m2 per year

5.

From 1 January 2021 nearly zero-energy building nearly zero-energy building nearly zero-energy building nearly zero-energy building

Notes.

1 The minimum permissible level (class) of energy efficiency of buildings for the buildings to be newly erected need not be applied if application of the relevant requirements is either technically or functionally impossible and benefit analysis on the useful lifetime of the relevant building indicates to losses.

2 Cabinet Regulation No. 383 of 9 July 2013, Regulations Regarding Energy Certification of Buildings.

Table 2

Minimum Permissible Level of Energy Efficiency of Buildings for Renewal and Rebuilding of Buildings

No.

Acceptance period of the documentation of the construction intention of the building

The minimum permissible level of energy efficiency of buildings, assessment of energy efficiency for heating for the buildings to be renewed and rebuilt

for residential buildings

for non-residential buildings

(the types of buildings referred to in Sub-paragraphs 6.1.3, 6.1.4, 6.1.5, 6.1.6, 6.1.7, 6.1.8, and 6.1.9 of the Regulation1)

multi-apartment buildings

one-apartment or two-apartment buildings

buildings which are in the ownership of the State or local government and in the possession of the authorities and where the State or local government authorities are located

other non-residential buildings

1.

From 21 November 2015 to 31 December 2020 ≤ 90 kWh/m2 per year ≤ 100 kWh/m2 per year ≤ 110 kWh/m2 per year ≤ 110 kWh/m2 per year

2.

From 1 January 2021 ≤ 80 kWh/m2 per year ≤ 90 kWh/m2 per year ≤ 90 kWh/m2 per year ≤ 100 kWh/m2 per year

Note. 1 Cabinet Regulation No. 383 of 9 July 2013, Regulations Regarding Energy Certification of Buildings.

Table 3

Maximum Permissible Levels of the Heat Transmittance Coefficients URM W/(m2 × K) and ψRM W/(m × K) of the Structure Element and the Linear Thermal Bridge

No.

Structure

Residential houses, homes for the elderly, hospitals, and kindergartens

Non-residential buildings

Production buildings

Value of URM, W/(m2K)

Value of URM, W/(m2K)

Value of URM, W/(m2K)

1.

Floor1:      

1.1.

floors and walls in contact with the ground

0.2

0.25

0.35

1.2.

floor to a non-heated basement or floor with a ventilated cellar

0.3

0.35

0.40

2.

External walls:      

2.1.

external walls

0.23

0.25

0.30

2.2.

walls in traditional log buildings without building of a thermal insulation layer into the wall

0.65

0.65

0.65

3.

Roofs and coverings which are in contact with outdoor air

0.20

0.23

0.25

4.

External doors and gates

1.80

2.00

2.20

5.

Windows and balcony doors2

1.10

1.10

1.30

6.

Thermal bridges, ψRM

0.20

0.20

0.35

Notes.

1 In all cases the calculation in accordance with the standard LVS EN ISO 13370:2017, Thermal performance of buildings - Heat transfer via the ground - Calculation methods (ISO 13370:2017).

2 The indicated value of U is the value of calculation in accordance with Table F3 of Annex F to the standard LVS EN ISO 10077-1:2017, Thermal performance of windows, doors and shutters - Calculation of thermal transmittance - Part 1: General (ISO 10077-1:2017). A standard window with the part of the frame in the amount of 30 % from the total area shall be viewed.

Table 4

Equivalent of Air Diffusion of Water Vapour Resistance sd for Membrane Materials

No.

Product or material

Equivalent of air diffusion of water vapour resistance sd (m)

1.

Polyethylene film 0.15 mm

50

2.

Polyethylene film 0.2 mm

75

3.

Polyethylene film 0.25 mm

100

4.

Polyester film 0.2 mm

50

5.

Polyvinyl chloride (PVC) film

30

6.

Aluminium foil 0.05 mm

1500

7.

Polyethylene film (squeeze-clamped) 0.15 mm

8

8.

Polyethylene film (squeeze-clamped) 0.20 mm

12

9.

Glassine 1 mm

2

10.

Prepared roofing paper

15

11.

Aluminium-based paper 0.4 mm

10

12.

Air pervious (breathing) windproof membrane

0.2

13.

Acrylic paint (0.1-0.2 mm layer)

1

14.

Latex paint (0.1 mm layer)

0.3

15.

Alkyd paint (0.1 mm layer)

4

16.

Polyurethane paint (0.03 mm layer)

4

17.

Silicate paint (0.1 mm layer)

0.2

18.

Vinyl wallpaper

2

Notes.

1. The warm side sd of the structure element is the value of such layers which are located before the layer of thermal insulation up to the first air layer to be ventilated (internal layer).

2. The cold side sd of the structure element is the value of such layers which are located after the layer of thermal insulation (inclusive) up to the first air layer to be ventilated (external layer).

3. For masonry and massive structure elements the total equivalent of air diffusion of water vapour resistance sd,i of the layers on the warm side thereof shall be not less than 2 m.

4. For structure elements of light-weight framework structures the total equivalent of air diffusion of water vapour resistance sd,i of the layers on the warm side thereof shall be not less than 5 m.

5. For structure elements of non-ventilated roofs with a non-ventilated structure of the roof covering the equivalent of air diffusion of water vapour resistance sd,i of the layers on the warm side thereof shall be not less than 50 m.

Table 5

Adjustment Coefficient Δλw W/(m × K) for Thermal Insulating Materials and Products to be Used in the Structure Elements Depending on the Working Conditions of Thermal Insulation

No.

Name of the thermal insulating material or product, specific resistance or density of air permeability

Working conditions of thermal insulation

Ventilated structure element

Δλw (W/mK)

Non-ventilated structure element

Δλw (W/mK)

1.

Mineral wool (rock wool, glass wool) products with Ra ≤ 6 kPa × s × m-2

0.006

0.008

2.

Mineral wool (rock wool, glass wool) products with Ra > 6 kPa × s × m-2

0.001

0.002

3.

Loose-fill mineral wool with Ra ≤ 6 kPa × s × m-2

0.008

may not be used

4.

Loose-fill pulp fibre (ecowool)
r > 25 kg/m3 (Ra > 6 kPa × s × m-2)

0.008

may not be used

5.

Hydraulically entangled pulp fibre
ρ = 35-75 kg/m3 (Ra > 6 kPa × s × m-2)

0.008

0.02

6.

Extruded polystyrene (XPS) plates

0.001

0.002

7.

Phenol and carbamide-formaldehyde plastic foam plates

0.02

0.03

8.

Aerated concrete ρ ≤ 400 kg/m3

0.015

0.02

9.

Aerated concrete 400 < ρ ≤ 600 kg/m3

0.03

0.04

10.

Aerated concrete ρ > 600 kg/m3

0.07

0.08

11.

Reed plates ρ = 200 kg/m3

0.035

may not be used

12.

Perchlor vinyl plastic foam sheets

0.012

0.015

13.

Expanded polystyrene (EPS) plates

0.003

0.004

14.

Foam gypsum ρ = 500 kg/m3

0.07

0.08

15.

Foam polyurethane and foam polyurethane plates

0.012

0.015

16.

Straw plates (with liquid glass binder) ρ = 350 kg/m3

0.045

may not be used

17.

Fibrolite plates

0.002

0.003

18.

Arbolite plates

0.015

0.017

19.

Keramzite concrete 400 < ρ ≤ 600 kg/m3

0.01

0.02

20.

Keramzite concrete 600 < ρ ≤ 800 kg/m3

0.025

0.045

21.

Keramzite concrete 800 < ρ ≤ 1000 kg/m3

0.05

0.07

22.

Peat plates 200 < ρ ≤ 300 kg/m3

0.015

0.02

23.

Crude fibre and particle plates ρ = 200 kg/m3

0.015

may not be used

24.

Crude fibre and particle plates ρ = 1000 kg/m3

0.11

may not be used

25.

Foam glass ρ = 200 kg/m3

0.02

0.025

26.

Foam glass ρ = 400 kg/m3

0.035

0.04

Note. In ventilated air separating layers the thermal insulating products shall be protected from outside by a wind barrier or the surface thereof shall be provided with a thermal insulating product against enforced convection effects upon the thermal conductivity of the thermal insulating material. This condition does not apply to cold attics in which the speed of the airflow above the thermal insulating materials does not exceed 0.5 m/s.

Table 6

Adjustment Coefficient Δλw W/(m × K) under Increased Humidity Conditions for Various Density r (kg/m3) Thermal Insulating Materials which are in Direct Contact with the Soil

No.

Insulating product

For unilateral contact with the ground

Δλw

For bilateral (mutual) contact with the ground

Δλw

1.

Aerated concrete ρ = 300-600 kg/m3

0.02-0.04

may not be used

2.

Keramzite concrete ρ = 400-600 kg/m3

0.01-0.02

may not be used

3.

Keramzite fill ρ = 200-400 kg/m3

0.05-0.06

0.06-0.07

4.

Mineral wool ρ ≥ 100 kg/m3

0.005

0.01

5.

Expanded polystyrene (EPS) ρ ≥ 30 kg/m3

0.01

0.02

6.

Extruded polystyrene (XPS) ρ ≥ 25 kg/m3

0.002

0.004

Table 7

Adjustment Coefficient Δλw W/(m × K) under Increased Humidity Conditions for Extruded Polystyrene (XPS) Plates the Density of which ρ = 25-40 kg/m3and which are in an Inverted Roof

No.

Type of a construction

Δλw (W/mK)

1.

Open ventilated surface:  

1.1.

one extruded polystyrene (XPS) layer and gravel dike

0.001

1.2.

two extruded polystyrene (XPS) layers and gravel dike

0.003

2.

Closed unventilated surface:  

2.1.

roof terraces with extruded polystyrene (XPS) thermal insulation and covered with humus

0.008

2.2.

extruded polystyrene insulation (XPS) under pavement

0.008

2.3.

extruded polystyrene (XPS) insulation under concrete surface in car parks

0.008

Table 8

Weight Humidity w of Construction Products in Percentage for the Calculation of Thermal Inertia

No.

Material

Weight humidity w (%)

1.

Expanded polystyrene (EPS)

10

2.

Foam polyurethane

5

3.

Reinforced concrete

3

4.

Keramzite concrete

10

5.

Slag concrete

8

6.

Aerated concrete

12

7.

Mortar

4

8.

Brick wall

4

9.

Conifers

20

10.

Oak

15

11.

Particle boards

12

12.

Sand

2

13.

Keramzite

3

14.

Slag

4

Table 9

Thermotechnical Characteristics of Construction Products and Calculation Values

No.

Material

Density
ρo (kg/m3)

Humidity at a relative air humidity of 50 % and at a temperature of 23 °C
u23,50 (kg/kg)

Humidity at a relative air humidity of 80 % and at a temperature of 23 °C
u23,80 (kg/kg)

Humidity conversion coefficient fu

Water vapour resistance factor µ

Specific heat capacity
c
J/(kg × K)

1.

Expanded polystyrene (EPS)

10-50

0.01

0.01

0.1

60

1450

2.

Extruded polystyrene (XPS)

20-65

0.001

0.0015

0.1

150

1450

3.

Foam polyurethane boards

28-55

0.02

0.03

0.3

60

1400

4.

Phenol plastic foam

20-50

0.02

0.03

0.2

50

1400

5.

Glass wool

10-120

0.004

0.005

2.5

1

1030

6.

Rock wool

15-200

0.004

0.005

2.5

1

1030

7.

Foam glass

100-150

0

0

0

106

1000

8.

Perlite boards

140-240

0.02

0.03

0.8

5

900

9.

Cork plates

90-160

0.05

0.07

1.0

10

1560

10.

Phenol and carbamide-formaldehyde plastic foam

10-30

0.1

0.15

0.7

2

1400

11.

Sprayed polyurethane foam

10-30

0.02

0.03

0.3

60

1400

12.

Wood wool with liquid glass

30-150

0.12

0.2

1.0

5

1600

13.

Wood wool with cement

250-450

0.06

0.1

1.0

5

1470

14.

Fibre board (soft)

150-250

0.1

0.16

1.5

10

1400

15.

Loose-fill glass wool

15-60

0.004

0.005

2.5

1

1030

16.

Loose-fill rock wool

20-60

0.004

0.005

2.5

1

1030

17.

Loose-fill cellulose-based fibre (Eco Wool)

20-60

0.11

0.18

0.5

2

1600

18.

Loose-fill foam perlite

30-150

0.01

0.02

3

2

900

19.

Loose-fill keramzite

200-400

0

0.001

4

2

1080

20.

Loose-fill expanded polystyrene (particulate matters)

10-30

0.01

0.02

0.2

2

1400

21.

Clay bricks

1000-2400

0.006

0.01

10

16

1000

22.

Calcium silicate

1000-2000

0.006

0.012

4

20

1000

23.

Pumice concrete

500-1300

0.025

0.045

2.6

50

1000

24.

Concrete with airtight filling

1600-2400

0.011

0.018

6.4

150

1000

25.

Industrially produced stone

1600-2400

0.011

0.018

6.4

150

1000

26.

Concrete filled with expanded polystyrene

600-1200

0.06

0.10

3

120

1000

27.

Keramzite concrete

400-700

0.02

0.03

2.6

6

1000

Table 10

Calculation Values of Thermotechnical Characteristics of Construction Products

No.

Group of materials

Material

Density
ρo (kg/m3)

Thermal conductivity λd
W/(m × K)

Specific heat capacity c J/(kg × K)

Water vapour resistance factor µ

1.

Metals aluminium

2700

220

890

∞ (106)

duralumin

2800

160

880

∞ (106)

brass

8400

120

380

∞ (106)

bronze

8700

65

380

∞ (106)

copper

8900

370

380

∞ (106)

low-carbon steel

7900

75

450

∞ (106)

pig iron

7500

50

450

∞ (106)

alloy steel

7800

50

450

∞ (106)

reinforcing steel

7850

58

480

∞ (106)

stainless steel

7900

17

460

∞ (106)

lead

11300

35

130

∞ (106)

zinc

7100

110

380

∞ (106)

2.

Wood and materials on the basis thereof homogeneous wood

150

0.07

1610

40

300

0.10

1610

40

500

0.13

1610

40

1000

0.24

1610

40

plywood

150

0.07

1610

400

300

0.10

1610

400

500

0.13

1610

400

1000

0.24

1610

400

particle board

300

0.10

1700

50

500

0.14

1700

50

700

0.18

1700

50

particle board with concrete binder

1200

0.23

1500

50

hardboard

400

0.09

1700

10

600

0.15

1700

10

800

0.18

1700

10

pressed paperboard

1000

0.23

2300

10

paper

1000

0.27

2300

-

corrugated cardboard

650

0.18

2300

7

3.

Gypsum gypsum

600

0.18

1000

10

1500

0.54

1000

10

gypsum paperboard

900

0.25

1050

10

4.

Mortar normal masonry mortar, mixed on the building site

1800

0.9

1100

10

5.

Concrete cast concrete with fragments or shingles

1600

0.7

1080

100

2400

2.0

1060

130

reinforced concrete

2500

2.0

840

100

clay with straw

800

0.4

1260

-

sawdust concrete

800

0.3

1460

2

1000

0.4

1520

2.5

slag concrete

1400

0.93

840

30

6.

Stones basalt

2700-3000

3.5

860

10000

granite

2500-3000

2.8

800

10000

sandstone

2000-2500

2.0

860

40

limestone

2000-2500

2.5

870

200

dolomite

2400

2.2

880

10

7.

Soils clay

1200-1800

1.5

1670-2500

-

gravel and sand

1700-2200

2.0

910-1180

-

8.

Water, ice, snow water (10 °C)

1000

0.6

4187

-

ice (0 °C)

900

2.2

2000

-

snow (new) < 30 mm

100

0.06

2000

-

snow (new)

30-70 mm

200

0.12

2000

-

snow (slightly sunk) 70-100 mm

300

0.23

2000

-

snow (significantly sunk) > 200 mm

500

0.70

2000

-

9.

Plastering cement-perlite

1000

0.3

840

4

cement-slag polystyrene (XPS)

1400

0.7

840

6

gypsum-perlite

600

0.25

840

4

gypsum

1300

0.65

840

6

limestone-sand-cement

1700

0.9

840

6

limestone-sand

1600

0.8

840

5

polymer cement

1800

1.0

840

10

10.

Glass quartz glass

-

1.4

700

∞ (106)

glass mosaic

2000

1.2

1000

∞ (106)

simple window glass

2500

1.0

720

∞ (106)

11.

Gas air

1.23

0.025

1008

1

argon

1.7

0.017

519

1

krypton

3.56

0.009

245

1

xenon

5.90

0.0055

160

1

carbon dioxide (CO2)

1.95

0.014

820

1

12.

Plastic, hard (without pores) acrylic

1050

0.20

-

10000

polycarbonate

1200

0.21

1200

5000

PTFE

2200

0.23

1000

10000

hard polyvinyl chloride (PVC)

1390

0.18

900

50000

polyvinyl chloride (PVC) with 40 % softener

1200

0.14

1000

50000

polyethylene, high density (HD)

980

0.40

1800

100000

polyethylene, low density (LD)

920

0.32

2100

100000

polystyrene

1050

0.18

1300

100000

polyacetal

1410

0.30

1400

100000

phenol-formaldehyde

1400-1800

0.3-0.7

1200

-

polypropylene

910

0.22

1700

10000

EPDM

1150

0.20

1000

6000

PMMA (acrylate)

1180

0.18

1500

-

polyurethane

1200

0.25

1800

6000

polyamide

1130

0.25

1700

-

epoxy resins

1200

0.23

800-1400

10000

13.

Silicones pure silicone

1000-1050

0.25-0.35

1000

5000

filled silicone

1300-1450

0.35-0.5

1000

5000

14.

Rubber polysobutylen

920

0.13

1130

-

butyl (hot smelted)

1200

0.24

-

200000

neoprene

1240

0.23

2140

 
porous rubber

60-80

0.04

1500

7000

15.

Glazing distance pieces solid butyl rubber

-

0.24

-

200000

polyester resins

1.4

0.19

1200

200000

Kiesel gel

-

0.13

-

-

silicone foam

-

0.12

-

-

16.

Materials for tamping nylon

1140

0.23

1700

-

urethane (liquid)

-

0.3

-

-

silicone foam

-

0.12

-

-

elastic vinyl

-

0.12

-

-

flexible porous rubber

70

0.05

-

-

polyethylene foam

36

0.06

2300

100

17.

Roofings asphalt

2100-2300

0.7

1500

50000

bitumen

1000

0.13

1000

50000

prepared roofing paper

1100

0.23

1000

50000

clay roof tiles

1900

0.9

900

10

concrete roof tiles

2100

1.4

1000

50

18.

Floor coverage linoleum

1300

0.17

1400

5000

cork linoleum

500-700

0.10

1300

1500

carpet floors

-

0.07

-

5

plastics and rubber

1200-1700

0.17-0.27

1400

10000

19.

Solid brick wall ceramic bricks sand-cement grout

1800

0.81

880

10

silicate bricks sand-cement grout

1800

0.87

880

10

20.

Hollow brick wall ceramic bricks 1400 kg/m3gross sand-cement grout

1600

0.64

880

155

ceramic bricks 1300 kg/m3gross sand-cement grout

1400

0.58

880

15

ceramic bricks 1000 kg/m3gross sand-cement grout

1200

0.52

880

15

silicate bricks sand-cement grout

1500

0.81

880

15

silicate bricks sand-cement grout

1400

0.76

880

15

Minister for Economics R. Nemiro

 


Translation © 2020 Valsts valodas centrs (State Language Centre)

 
Document information
Title: Noteikumi par Latvijas būvnormatīvu LBN 002-19 "Ēku norobežojošo konstrukciju siltumtehnika" Status:
In force
in force
Issuer: Cabinet of Ministers Type: regulation Document number: 280Adoption: 25.06.2019.Entry into force: 01.01.2020.Publication: Latvijas Vēstnesis, 135, 05.07.2019. OP number: 2019/135.2
Language:
LVEN
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