REPORT ON THE CALCULATION OF THE COST OPTIMAL LEVELS … · requirements for buildings in the new...

REPORT ON THE CALCULATION OF THE COST-OPTIMAL LEVELS OF THE MINIMUM ENERGY PERFORMANCE

REQUIREMENTS FOR BUILDINGS IN THE NEW SPANISH REGULATIONS AND THEIR COMPARISON WITH THE

CURRENT REQUIREMENTS

Version 1.0/ July 2018

Report on the calculation of the cost-optimal levels of the minimum energy performance requirements for buildings in the new Spanish regulations and their comparison with the current requirements

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Spain’s Ministry of Public Works, Directorate-General for Architecture, Housing and Land Development

Paseo de la Castellana, 112. 28071 Madrid, Spain

Tel.: +34917284000

Website: http://www.fomento.es

E-mail: [email protected]

Version 1.0/ July 2018

This document was prepared by the Directorate-General for Architecture, Housing and Land Development of Spain's Ministry of Public Works based on the information from the cost-optimal study carried out by the Building Energy and Sustainability Group of the Quality in Construction Unit of the Eduardo Torroja Institute of Construction Science.


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SUMMARY

This document includes the optimal cost report and the comparison between the current requirements and those proposed for Spain’s new energy efficiency regulation as established by Directive 2010/31/EU and Delegated Regulation (EU) No 244/2012.

Six reference buildings were used for both new and existing buildings. Combined with the three representative climate zones used, this gives a total of 36 subcategories of buildings. On the basis, numerous improvement measures have been used in a combination of packages that include both measures relating to the envelope and measures relating to the systems for calculating the final cost-optimal values.

The financial perspective used for the final cost calculation scenario applied a discount rate of 7 % for new buildings and 10 % for existing buildings. For the evaluation and the study of the macro-economic perspective (which ultimately was not used to establish the optimum levels), a rate of 3 % and 4 % was used for new and existing buildings respectively.

In order to assess the robustness of the results, a sensitivity analysis was carried out for the update rates and also for the energy prices, both in the financial and the macroeconomic scenarios. The findings revealed that for the range of variation analysed, the results are not very sensitive to these factors.


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In the final scenario (financial analysis, rate of 7 % for new buildings and 10 % for existing buildings) and the energy price evolution of the baseline scenario, the proposed levels of energy efficiency for the revision of the CTE DB-HE 2018 are adequate in relation to the optimal cost (over 15% is less than optimal).

Table of Contents

1. Introduction ..................................................................................................................................... 6 2. REFERENCE BUILDINGS .................................................................................................................... 7

2.1 Categories of use ..................................................................................................................... 7 2.2 Climate zones .......................................................................................................................... 8 2.3 Types of buildings .................................................................................................................... 8

3. Measures to improve energy efficiency and packages of measures ............................................. 10 3.1 Measures concerning the thermal envelope ........................................................................ 10 3.2 Measures relating to the technical systems .......................................................................... 12 3.3 Packages of measures ........................................................................................................... 13

4. Variants calculated ........................................................................................................................ 14 5. Calculation of the primary energy consumption of the measures ................................................ 15

5.1 Energy efficiency assessment ................................................................................................ 15 5.2 Calculation of the energy demand and consumption ........................................................... 15

5.2.1 Factors for converting to primary energy and emissions ......................................... 15 5.2.2 Results of the energy consumption calculation ........................................................ 16

6. Global cost calculation ................................................................................................................... 17 6.1 Calculation period ................................................................................................................. 18 6.2 Service life of the components .............................................................................................. 18 6.3 Costs considered ................................................................................................................... 18 6.4 Cost of the components ........................................................................................................ 18 6.5 Energy prices ......................................................................................................................... 19 6.6 Cost of CO2 emissions ............................................................................................................ 20 6.7 Update rate ........................................................................................................................... 21 6.8 Results and calculation of the global cost ............................................................................. 21

7. Optimal-cost levels for the reference buildings ............................................................................ 24 8. Selection of the energy efficiency regulatory standards ............................................................... 25 9. Comparison .................................................................................................................................... 27 10. Analysis, conclusions and justification of the differences found ........................................... 29


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1. Introduction

The objective of this document is to determine optimal levels of cost efficiency through optimal cost studies and compare them to the current and future minimum requirements in Spain in the context of:

- Article 4 of Directive 2010/31/EC of 19 May 2010 on the Energy Performance of Buildings (EPBD)1.

- Delegated Regulation 244/2012 of 16 January 2012 supplementing Directive 2010/31/EU on the energy performance of buildings by establishing a comparative methodology framework for calculating cost-optimal levels of minimum energy performance requirements for buildings and building elements2.

- Directives accompanying Delegated Regulation 244/2012 of 16 January 2012 supplementing Directive 2010/31/EU on the energy performance of buildings by establishing a comparative methodology framework for calculating cost-optimal levels of minimum energy performance requirements for buildings and building elements3.

This document sets out the methodology, criteria and work plan developed to achieve the cost-optimal levels and regulatory values finally proposed. Lastly, Annex III to the document contains the reporting template provided in Delegated Regulation (EC) No 244/2012.

In accordance with the Delegated Regulation (RD), the cost-optimal level will initially be established:

in terms of non-renewable primary energy;

for complete buildings and simultaneously considering the energy uses associated with each

type of building.

1 http://www.boe.es/doue/2010/153/L00013-00035.pdf

2 http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2012:081:0018:0036:EN:PDF

3 http://eurlex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:C:2012:115:0001:0028:EN:PDF


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2. REFERENCE BUILDINGS

2.1 Categories of use

In selecting the reference buildings, account was taken of their representativeness with respect to the statistics of the Spanish building stock on the basis of the official census data of the Ministry of Public Works and of the National Statistics Institute [Instituto Nacional de Estadística - INE].

Based on the information available in the Long-term strategy for energy rehabilitation in the building sector in Spain (ELP14) and the Construction statistics. Works management visas up to 2012 (EE16) of the Ministry of Public Works, the number of buildings and surface area constructed by use types is shown in the following table:

Table 1. Distribution of building stock surface areas by property register use (2011 census)

Buildings [No]

Surface area [m2]

Surface area by

group [%]

Surface area

Average [m2]

RESIDENTIAL 23142267 3283305198 100 % 142

V1a – Detached or semi-detached single-family 2314227 476592857 14.52 % 206

V1b – Terraced or row single-family 4535884 832117251 25.34 % 183

V2a – Multi-family building, detached block 5577286 675962240 20.59 % 121

V2b – Multi-family building occupying a whole block 10714870 1298632850 39.55 % 121

TERTIARY, SERVICES AND EQUIPMENT 1967237 825585829 100 % 420

O – Offices 283352 111291436 13 % 393

E – Cultural 47582 97067969 12 % 2040

Y - Healthcare and welfare 37382 48131972 6 % 1288

G – Leisure and hospitality 196868 107481444 13 % 546

K – Sports 57926 201004443 24 % 3470

C – Commercial 1295359 223541711 27 % 173

T – Performances 5303 8085756 1 % 1525

R – Religious 43465 28981098 4 % 667

INDUSTRIAL 1703522 704912001 100 % 414

STORAGE - PARKING 7984295 345084908 100 % 43

OTHERS 239581 117332565 100 % 490

POPULATION (%) 35036902 5276220501 151

* For the distribution of the number of buildings in residential use, the average size was assumed to be equal within the subtypes of single-family residences and residences in detached blocks, and a built surface area for single-family residence equal to the average size of the residence; ** For the distribution by built surface area in residential use, the average size of the single-family residences was considered to be 1.5 times that of the residences in detached blocks, according to the data from the Ministry of Public Works (EE16), along with the distribution (ELP14) of the number of residences by type (V1: 10 \%, V2:19.6\%, V3:24.1\% and V4: 46.3\%); *** Uses for which the Delegated Regulation for Directive 2010/31/EU requires the definition of a reference building (one for new buildings and one for existing buildings)

Based on this study of the building stock, to characterise the residential use (housing) of single-family type buildings, two single-family type buildings and two multi-family type


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buildings were selected, along with an office building with a typical use-time of eight hours per day and an average internal load, and an office building (courthouse) with a typical use time of 16 hours per day and an internal load that is also average.

These use categories are representative of 83 % of the total built area and their distribution is broken down in the following table.

Table 2. Construction of the types of reference buildings (in % with respect to the built area) in relation to the total/population and to each use

Type Single-family

housing type a) EPBD

Multi-family housing, terraced

type b) EPBD

Multi-family housing, detached

type b) EPBD

Offices type c) EPBD

TOTAL

Residential use 79.9 %

Sub-category of use

30.9 % 32.2 % 16.8 %

Tertiary use 20.1 %

Sub-category of use

2.7 %

2.2 Climate zones

The use categories are also subdivided based on the buildings’ location in different climate zones. These climate zones are established based on the CTE DB-HE climate classification. Each zone is marked by a letter, which represents the climatic severity of the winter (α, A, B, C, D and E), and a number, which represents the climatic severity of the summer (1, 2, 3 and 4).

The following table sets out the population distribution in each climate zone, calculated according to the CTE DB-HE climate zoning and the data on population, geographic altitude, and provincial capital by municipalities.

Table 3. Population by climate zone

Climate zone

A3 A4 B3 B4 C1 C2 C3 C4 D1 D2 D3 E1 α3c A2C B2C C2c

POPULATION (%) 2.47 1.80 13.79 8.50 8.45 11.38 6.61 4.25 6.13 5.72 22.00 4.39 2.92 1.35 0.21 0.02

Taking into account an adequate representation of the different climate zones and taking as a hypothesis a distribution of the built surface area similar to that of the resident population in each zone, subcategories corresponding to the location in the climate zones B3, D3 and C2, in which almost 50% of the population are situated, were defined for the study.

2.3 Types of buildings

Taking into account the categories of use and climate distribution of the buildings, several representative geometric types were selected.

Given the high prevalence of buildings from the second half of the twentieth century and the early twenty-first century, it was considered possible to use these types to analyse the behaviour of new and existing buildings, with the two cases differing not as a result of their geometric features but of their construction features.


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Table 4. Reference buildings for new and existing buildings

Category Sub-category Floor

area [m2] Subtypes Name

RESIDENTIAL

a Single family Detached housing 270

3, one per climate zone N_R05_unif_aislada

a Single family Detached housing 200

3, one per climate zone N_R09_unif

b Multi family Terraced block 1674 3, one per

climate zone N_R02_plurif_entrem

b Multi family Detached

block 534 3, one per

climate zone N_R07_plurif_aislada

NON-RESIDENTIAL

c Offices Offices 8M 1073 3, one per

climate zone N_T01_oficinas_08M

c Offices Court buildings

16M 13000 3, one per

climate zone N_T02_juzgados_16M

TOTAL

18 new buildings

18 existing buildings

The combination of the 6 types of buildings and 3 climate zones give rise to 18 subtypes of buildings for new construction and to 18 subtypes for existing buildings.

Annex I includes the detailed tables defining the reference buildings for existing buildings (major refurbishments) and new buildings.


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3. Measures to improve energy efficiency and packages of measures

The measures to improve energy efficiency selected can be divided into measures that affect the envelope and measures that affect the systems.

3.1 Measures concerning the thermal envelope

The measures related to improving the envelope are structured into levels of insulation of the different opaque building components as well as into improvements of the characteristics of the cavities (glass-frame combination) as set out in the following tables:

Table 5. Characterisation of the types of cavities as improvement measure Level Carpentry Ucarp Type of glass Uglass gglass Utotal

H0 Metallic without thermal breaks 5.70 Single 6mm 5.70 0.85 5.70

H1 Metallic with thermal breaks 1.30 4/16/6 2.70 0.78 2.42

H2 Metallic with thermal breaks 1.30 BE 4/16/6 1.10 0.63 1.14

H3 Metallic with thermal breaks 1.30 BE_CS 4/16/6 1.00 0.42 1.06

Table 6. Characterisation of the levels of insulation of opaques as improvement measure Level Thermal insulation in opaques

(thickness in cm)

U_façades

(W/m2K) U_roofs

(W/m2K) U_flooring

(W/m2K)

A0 0 1 859 2 652 3 159

A1 2 0.86 0 998 1 062

A2 4 0 559 0 615 0 638

A3 6 0 414 0 444 0 456

A4 8 0 329 0 348 0 355

A5 10 0 273 0 286 0 291

A6 12 0 233 0 242 0 246

On the basis of this classification, different thermal envelope (ET) packages were established, which are applied as improvement measures to the study models:

Table 7. Characterisation of the improvement measures relating to the thermal envelope

ET0 ET1 ET1_CS ET2 ET2_CS ET3 ET3_CS ET4 ET5

FAÇADE A0 A1 A1 A2 A2 A3 A3 A4 A5

ROOF A0 A2 A2 A3 A3 A4 A4 A5 A6

FLOOR A0 A0 A0 A1 A1 A2 A2 A3 A3

CAVITY H0 H1 H3 H1 H3 H2 H3 H2 H3


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3.2 Measures relating to the technical systems

Systems identified as energy efficiency measures and their performances are shown in the following table.

Table 8. Characterisation of the improvement measures relating to the technical systems

Performances in individual systems (Ƞ) Performances in centralised systems (Ƞ)

Service Generation Distribution+emission+control Generation Distribution+emission+control

S1 Natural gas boiler

Heating 0.95 0.95 0.95 0.90

Domestic hot water 0.90 0.88 0.90 0.84

S2 Biomass boiler

Heating 0.85 0.95 0.85 0.90


S3 Heat pump (air-to-air)

Heating 3.00 0.95 3.00 0.90

Cooling 2.50 0.95 2.50 0.90

Domestic hot water

3.00 0.88 3.00 0.84

S4

Cogeneration

Heating 0.65 0.95 0.65 0.90


Elect. 0.25 1.00 0.25 1.00

T1, T2

Thermal solar panels

0.30 - - -

F1, F2

Photovoltaic panels

0.10 - - -

V1

Heat recovery units (dual flow)

0.70 - 0.70 -


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3.3 Packages of measures

Based on the measures to improve the energy efficiency of the thermal envelope and technical systems, packages were put together that apply to reference buildings based on their different types, size and features (new or existing) and their climate zone. These packages are listed in the table below:

Table 9. Packages of measures to improve energy efficiency New buildings Existing buildings

ET2+S1+T1 ET1+S1

ET2+S1+T1+V1 ET1+S1+V1 ET2+S2+T1+V1 ET1+S1+T1 ET2+S3+T1+V1 ET1+S1+T2 ET2+S3+T2+F1+V1 ET1+S1+T1+V1 ET2+S4+T1+V1 ET1+S1+T2+V1 ET2+CS+S1+T1 ET1+S2+V1 ET3+S1+T1 ET1+S2+T1+V1 ET3+S1+T1+V1 ET1+S3+T1+V1 ET3+S2+T1+V1 ET1+S3+T1+F1+V1 ET3+S3+T1+V1 ET1+S3+T2+F1+V1 ET3+S3+T2+F1+V1 ET1+S3+T2+F2+V1 ET3+S3+T2+F2+V1 ET1+S4+T1+V1 ET3+S4+T1+V1 ET1+S4+V1 ET3+CS+S1+T1 ET1+CS+S1 ET3+CS+S1+T1+V1 ET1+CS+S1+T1 ET3+CS+S2+T1+V1 ET1+CS+S1+V1 ET3+CS+S3+T1+F1+V1 ET1+CS+S2+V1 ET3+CS+S1+T2+V1 ET1+CS+S3+T1+F1+V1 ET4+S1+T1 ET2+S1 ET4+S1+T1+V1 ET2+S1+T1 ET4+S1+T2+V1 ET2+S1+T1+V1 ET4+S2+T1+V1 ET2+S3+T1+V1 ET4+S3+T1+V1 ET4+S3+T1+F1+V1 ET4+S3+T2+F1+V1 ET4+S3+T2+F2+V1 ET4+S4+T1+V1 ET5+S1+T1+V1

Annex II contains a detailed table of the measures and variants selected.


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4. Variants calculated

The combination of the different types, categories and sub-types of buildings with the packages of measures applicable to each case results in a set of variants which will be analysed to calculate the optimal values.

Annex III contains the table with the relevant data for each variant in terms of energy efficiency.


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5. Calculation of the primary energy consumption of the measures

5.1 Energy efficiency assessment

The energy consumption of the set of reference buildings with the various improvement measures applied is obtained by thermal simulation using the OpenStudio software.

This set of buildings, which is referred to as ‘all cases’, is characterised by its thermal and lifecycle cost parameters, following the methodology of the standard EN ISO 52000-1 and the conditions laid down in the CTE DB-HE which also includes the usable climate data, and [the conditions laid down] in the RITE’s Document of the Technical Conditions for Assessing the Energy Performance of Buildings, to which the CTE DB-HE itself refers.

The selected variants comply with the applicable requirements as regards their energy efficiency.

For the calculation of the non-renewable primary energy consumption of residential buildings account is taken of the consumption of heating, cooling, ventilation and domestic hot water services, while consumption of lighting is also taken into account for the calculation for non-residential buildings.

5.2 Calculation of the energy demand and consumption

Energy requirements are calculated by means of an hourly calculation method with the hypothetical external and internal stresses and operating conditions specified in the current regulations.

To determine the regulatory levels, hundreds of thousands of cases were calculated, involving more types, climates and uses than those set out in this report.

5.2.1 Factors for converting to primary energy and emissions

For the purpose of calculating the primary energy and CO2 emissions based on the final energy consumption, the values considered were those set out in the RITE document CO2 emission factors and the coefficients for conversion to primary energy for different sources of final energy consumed in the buildings sector in Spain, effective as of 14 January 2016, and which are reproduced in the following table.

Table 10. Factors for converting from final energy to primary energy and CO2 emissions

A Renewable primary energy (kWhprim/ kWhf)

A Non-renewable primary energy (kWhprim/ kWhf)

emissions (kgCO2/ kWhf )

PENINSULAR/MAINLAND ELECTRICITY 0 414 1 954 0 331

BALEARICS ELECTRICITY 0 082 2 968 0 932

CANARIES ELECTRICITY 0 070 2 924 0 776

CEUTA AND MELILLA ELECTRICITY 0 072 2 718 0 721

HEATING GAS OIL 0 003 1 179 0 311

LPG 0 003 1 201 0 254

NATURAL GAS 0 005 1 190 0 252


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COAL 0 002 1 082 0 472

NON-DENSIFIED BIOMASS 1 003 0 034 0 018

DENSIFIED BIOMASS (PELLETS) 1 028 0 085 0 018

For the optimal cost study, the factors considered for electricity were those relevant for mainland electricity and for biomass, those for densified biomass. To set the regulatory values, the influence of the variation of the factors for conversion off the mainland was analysed, applying appropriate correction factors.

5.2.2 Results of the energy consumption calculation

Annex IV contains detailed tables with the results of the energy demand calculation.


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6. Global cost calculation

The global cost was calculated from a dual perspective: financial (or microeconomic) and macroeconomic, although the regulatory values were selected on the basis of the financial analysis.

The categories of cost taken into account are:

Initial investment cost

Replacement cost

Maintenance cost

Energy cost

Residual value

CO2 emissions (only in the macroeconomic analysis)

In the financial analysis all the costs include fees and taxes.

The global cost of the buildings and their components is calculated by totalling the different types of costs and applying an update rate to these by means of an update factor, in order to express them in terms of value in the first year. The updated residual value is added to the result obtained as follows:

The update rate (r) means the defined value that is used to compare at different times the value of money expressed in real terms excluding inflation. The update rate includes the cost of the capital in the methodology presented by the Commission for the calculation of the annual costs.

Thus, on the basis of the update rate and the number of years elapsed since the initial period (p), the update factor (Rd(p)) or number by which the cash flow recorded at a given time is calculated to obtain its equivalent value at the initial point.


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6.1 Calculation period

The calculation period for the lifecycle analysis was set at 30 years for residential use and 20 years for non-residential or tertiary use.

6.2 Service life of the components

The service life of the various building components is set out in the following terms:

Table 11. Service life of the building components Service life Maintenance period

Windows 30 years 10 years

Facilities (from EN 15459 onwards) 20 years 1 year

Other components (opaques, building) 50 years 10 years

6.3 Costs considered

The following costs were considered :

Table 12. Costs considered

Cost Value 0 %

Initial cost CI

Replacement costs Equal to CI

Maintenance costs 0,1% CI / period

Energy costs (operation)

See tables 13, 14 and 15

Residual value Linear amortisation CI

Costs exclusive to the macroeconomic analysis

Cost of CO2 emissions See Table 16

Costs exclusive to the financial or microeconomic analysis

Municipal taxes (permits) 7% CI

Value added tax

- for new residential and tertiary 21 % CI

- for residential upgrading 10 % CI

6.4 Cost of the components

The initial cost (CI) was compiled from recent construction and project prices, along with data from builders’ associations and professional associations.

Annex V contains detailed data on the initial costs and the maintenance costs of the energy efficiency improvement measures.


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6.5 Energy prices

Both the actual prices and the scenarios forecast for the base year 2015 were made on the basis of the following documents:

IDAE document: lnforme de precios energéticos: combustibles y carburantes enero 2015

IDAE document: Informe_precios_biomasa_usos_térmicos: pellet no certificado

EUROSTAT Energy Price statistics

The evolution of electricity and fuel prices in the baseline scenario was taken from the trends provided by the European Commission (EU Energy, transport and GHG emissions trends to 2050).

The values used are as follows, depending on the financial scenario chosen and in euros at constant 2015 rates):

Table 13. Energy prices in the baseline scenario (macroeconomic analysis)

Energy prices (€/kWh) 2015 2020 2025 2030 2035 2040 2045 2050

NATURAL GAS 0.058 0.060 0.055 0.062 0.060 0.062 0.062 0.059

ELECTRICITY 0.190 0.232 0.232 0.238 0.238 0.232 0.232 0.232

BIOMASS 0.042 0.052 0.052 0.053 0.053 0.052 0.052 0.052

GAS OIL 0.040 0.085 0.085 0.089 0.093 0.100 0.104 0.108

LPG 0.047 0.101 0.101 0.105 0.110 0.119 0.123 0.127

Table 14. Energy prices in the baseline scenario (financial analysis)

Energy prices (Micro) (€/kWh)

2015 2020 2025 2030 2035 2040 2045 2050

NATURAL GAS 0.070 0.072 0.067 0.075 0.073 0.075 0.075 0.072

ELECTRICITY 0.237 0.289 0.289 0.297 0.297 0.289 0.289 0.289

BIOMASS 0.051 0.063 0.063 0.064 0.064 0.063 0.063 0.063

GAS OIL 0.058 0.125 0.125 0.130 0.135 0.146 0.152 0.157

LPG 0.057 0.122 0.122 0.128 0.133 0.144 0.149 0.154

For the sensitivity analysis, an alternative scenario for the development of energy prices was considered, which incorporates an additional 1.5 % annual price increase4.

Table 15. Energy prices in the alternative scenario (financial analysis) Energy prices (Micro)

(€/kWh) 2015 2020 2025 2030 2035 2040 2045 2050

NATURAL GAS 0.070 0.078 0.078 0.094 0.098 0.109 0.117 0.121

ELECTRICITY 0.237 0.311 0.335 0.371 0.400 0.419 0.452 0.487

BIOMASS 0.051 0.068 0.073 0.080 0.086 0.091 0.098 0.106

4 In this scenario, the energy costs in the calculation period can be obtained by applying a factor of 23.12 to the annual energy cost if the calculation period is 20 years and a factor of 37.54 if the calculation period is 30 years.

http://www.idae.es/uploads/documentos/documentos_Combustibles_y_carburantes_enero_2015_52c84392.pdfhttp://www.idae.es/uploads/documentos/documentos_Combustibles_y_carburantes_enero_2015_52c84392.pdfhttp://www.idae.es/uploads/documentos/documentos_Informe_Precios_Biomasa_Usos_Termicos_1T_2016_v1_df54c937.pdfhttps://ec.europa.eu/transport/sites/transport/files/media/publications/doc/trends-to-2050-update-2013.pdfhttps://ec.europa.eu/transport/sites/transport/files/media/publications/doc/trends-to-2050-update-2013.pdf


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GAS OIL 0.058 0.135 0.145 0.163 0.182 0.212 0.238 0.264

LPG 0.057 0.131 0.142 0.160 0.179 0.209 0.233 0.259

Figure1. Energy cost scenarios (financial analysis)

Alternative reference scenario for the evolution of energy costs (financial analysis) (€_2015/kWh)

6.6 Cost of CO2 emissions

The cost of CO2 emissions is taken into account for the macroeconomic optimal cost

calculations.

The values were taken from the reference scenario in Annex II to Delegated Regulation (EU)

No 244/2012, updating the prices for the base year 2010 to the base year 2015, with an

inflation rate of 3 %.

Table 16. Cost of CO2 emissions

2015 2020 2025 2030 2035 2040 2045 2050

CO2 prices (€2015/kgCO2)

0.0058 0.0116 0.067 0.075 0.073 0.075 0.075 0.072

*( Values updated from 2010 to 2015 with inflation of 3% - k=1.16)


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Figure 2. Reference scenarios for the cost of CO2 emissions Emission cost scenario

6.7 Update rate

For the optimal cost calculation at macroeconomic level, update rate values of 3 % and 4 % were used for new buildings and existing buildings, respectively.

For the optimal cost calculation at financial (microeconomic) level, update rate values of 7 % and 10 % were used for new buildings and existing buildings, respectively.

Finally, to calculate the levels of regulatory indicators, the financial perspective used an update rate of 7 % for new buildings and 10 % for existing buildings.

This choice was based on the type of financing available, usually mortgages or self-financing in the case of new buildings, as well as alternative investment options and the cost of the personal loans in the case of existing buildings.

6.8 Results and calculation of the global cost

The following tables show the results of optimal non-renewable primary energy consumption

at cost, including different scenarios allowing for the performance of a sensitivity analysis of

the discount rate, the type of analysis (financial or macroeconomic), and of the energy costs

(using the baseline scenario and an alternative scenario with an additional annual 1.5 %

increase in energy costs).

Table 17. Non-renewable primary energy consumption in financial analysis scenarios

EPnren;opt [kWh/m2·an]

Energy cost scenarios Base Alternative

Discount rate (financial analysis) 7 % 10 % 7 % 10 %

NEW BUILDINGS

N_R05_unif_aislada [single-family, detached] 46.0 46.0 46.0 46.0

N_R09_unif [single family] 59.8 59.8 59.8 59.8

N_R02_plurif_entrem [multi-family, terraced] 42.1 42.1 42.1 42.1

N_R07_plurif_aislada [multi-family, terraced] 47.2 47.2 47.2 47.2


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N_T01_oficinas_08M [offices 08M] 61.7 61.7 61.7 61.7

N_T02_juzgados_16M [court buildings 16M] 130.2 116.6 130.2 116.6

EXISTING BUILDINGS

N_R05_unif_aislada 76.1 76.1 76.1 76.1

N_R09_unif 80.8 80.8 80.8 80.8

N_R02_plurif_entrem 63.8 63.8 63.8 63.8

N_R07_plurif_aislada 76.4 76.4 76.4 76.4

N_T01_oficinas_08M 58.6 58.6 58.6 58.6

N_T02_juzgados_16M 119.3 112.6 119.3 112.6

Table 18. Non-renewable primary energy consumption in macroeconomic analysis scenarios

EPnren;opt [kWh/m2·an]

Energy cost scenarios Base Alternative

Discount rate (macroeconomic analysis) 3 % 4 % 3 % 4 %

NEW BUILDINGS

N_R05_unif_aislada 43.7 46.0 43.7 46.0

N_R09_unif 49.6 49.6 49.6 49.6

N_R02_plurif_entrem 27.3 27.3 27.3 27.3


N_T01_oficinas_08M 39.9 39.9 39.9 39.9

N_T02_juzgados_16M 130.2 130.2 130.2 130.2

EXISTING BUILDINGS

N_R05_unif_aislada 55.8 55.8 55.8 55.8

N_R09_unif 69.3 69.3 69.3 69.3

N_R02_plurif_entrem 10.5 24.3 10.5 24.3


N_T01_oficinas_08M 36.0 36.0 36.0 36.0

N_T02_juzgados_16M 122.7 122.7 122.7 122.7

Annex VI contains details of the results and the calculation of the global cost for the different

scenarios shown.

Annex VII contains the set of graphs of the results of the calculation of the global cost in the

different scenarios postulated, included the cost-optimal levels, the existing regulations (DB-

HE2013) and proposed regulations (DB-HE2018).


23

The sensitivity analysis shows that changes in the discount rate and in the analysis

scenario (financial or macroeconomic) do not have a significant impact at the optimal

levels. Likewise, the results are very stable compared with variations in energy prices.


24

7. Optimal-cost levels for the reference buildings

Although the global cost is calculated with both the financial and the macroeconomic

perspective, the regulatory levels at national level are defined on the basis of the financial

perspective, using the rates of 7 % and 10 % for new and existing buildings,

respectively, and for a baseline scenario for energy prices.

The following table lists the values of the non-renewable primary energy consumption

obtained at the optimal cost for each reference building (as an average of the values for each

subtype, by climate zone).

Table 19. Optimal values for non-renewable primary energy consumption [kWh/m2·an]

Reference building EPnren;opt

NEW BUILDINGS (financial analysis, 7%, base)

N_R05_unif_aislada 46.0

N_R09_unif 59.8

N_R02_plurif_entrem 42.1

N_R07_plurif_aislada 47.2

N_T01_oficinas_08M 61.7

N_T02_juzgados_16M 130.2

EXISTING BUILDINGS (financial analysis, 10 %, base)

N_R05_unif_aislada 76.1

N_R09_unif 80.8

N_R02_plurif_entrem 63.8

N_R07_plurif_aislada 76.4

N_T01_oficinas_08M 58.6

N_T02_juzgados_16M 112.6


25

8. Selection of the energy efficiency regulatory standards

From the total set of cases simulated, a subset is selected, which is called a region of interest, representative of the desired efficiency levels and which meets the following conditions:

1) the thermal envelope complies with the thermal transmittance limit values set out in

CTE DB-HE 2013;

2) the aggregate demand, in the case of existing buildings with private residential use,

or the demand for heating and cooling in the case of new buildings with private

residential use is below the limit value laid down in the CTE DB-HE2013;

3) the non-renewable primary energy consumption of new buildings in private residential

use is below the limit value laid down in the CTE DB-HE 2013;

4) the building, in the case of new buildings in private residential use, has a thermal

solar panel system ensuring the minimum solar coverage established in the CTE DB-

HE 2013;

5) the non-renewable primary energy consumption (EPnren) is less than in the cost-

optimal case;

6) the cost is in the lower half of the cases that meet the above conditions (50 %

percentile in cost).

These conditions cover the requirements for cost optimisation and for compliance with the existing requirements5.

The following figure shows an example of the selection of the region of interest (with a green background) for a newly built residential building situated in the mainland climate zone A3, drawing from all the cases calculated for those conditions.

Figure 3: Region of interest of a new residential building in A3 zone

5 In tertiary use, the selection of candidates was not limited to those that meet the condition for the B rating in CEP;nren, but this condition is trivial with regard to improving the performances of the selected units by more than 35 % of the performances of the reference units. The limitation of demand savings was also not imposed since the installation’s energy efficiency value is 30 % of the benchmark and the linear thermal transmittance values of thermal bridges are in the order of some 10 % of those of the benchmarks.


26

In the case of existing buildings, the condition that the envelope comply with the 2013 limits is stricter than necessary since there may be partial interventions on the envelope due to technical, economic or legal impossibility. In the case of existing residential building systems, consideration was has also given, on the safety side, to capacity to produce domestic hot water with solar thermal panels, though the demand for domestic hot water would not be required in most cases due to urban planning or protection constraints. Thus, the selection criteria for the region of interest and the representative value have been made more flexible compared to those applied to new buildings.

The selection of the regulatory values of the indicators is obtained by using a linear regression of the representative indicator value for the subset of selected cases (buildings type), using as the regression parameters and depending on the indicator: the winter climate zone (ZCI, depending on the winter day degrees, HDD-18), the compactness of the building (V/A) or the intensity of the internal sources (CFI).

The representative value used was the optimal cost for the secondary indicators (K, CEP;tot) and the 75 % percentile for the optimal cost for the non-renewable primary energy indicator (CEP;nren).

The 95 % confidence interval bands of the regression estimator were also calculated, selecting the upper value the for secondary and central indicators in that of the principal indicator.

The following table summarises these criteria.

Table 20. Criteria for selecting the indicators set out in the regulations CEP;nren CEP;tot K qsol;jul

Dependent variables ZCI, CFI ZCI, CFI ZCI, V/A CFI

NEW BUILDINGS

Residential A B B

Tertiary A B B

EXISTING BUILDINGS

Residential B B B

Tertiary B B B

A: Central regression value for the 75 % percentile, for a 95 % confidence interval.

B: Upper regression value, for a 95 % confidence interval.

The values are rounded up to the next integer and the average for the selected climates remains within 15 % of the optimal cost value.


27

9. Comparison

The existing regulatory requirements for energy efficiency in buildings in Spain are set out in

the Basic Document DB-HE “Energy Saving” of the Technical Building Code [Código Técnico

de la Edificación - CTE].

The Technical Building Code was initially approved by Royal Decree 314/2006 of 17 March

2006, as the regulatory framework laying down basic performance requirements for

buildings, in line with the basic requirements laid down in the Building Planning Law [Ley de

Ordenación de la Edificación - LOE] 38/1999 of 5 November 1999. To support innovation

and technical development, the CTE adopted, to the extent possible, the services-based

perspective, such as the more advanced, modern and internationally accepted approach in

the field of building regulations.

The DB-HE “Energy Saving” Basic Document was revised in 2013, setting basic

requirements in terms of the consumption of non-renewable primary energy (HE0), energy

demand and envelope characteristics (HE1), technical systems efficiency (HE2), and the use

of renewable energy (HE3, HE4) for both new and existing buildings. Those requirements

were established according to optimal cost studies in accordance with the criteria set out in

Directive 2010/31/EU of the European Parliament and of the Council of 19 May 2010 on the

energy performance of buildings (EPBD) and of Commission Delegated Regulation (EU) No

244/2012 of 16 January 2012.

In line with the requirements established in the (EPBD) Directive, a review of the DB-HE

2018 was proposed using the criteria established in this study.

The following table shows the results of this optimal cost study with the non-renewable

primary energy consumption values set out in the DB-HE 2013 and those proposed for the

update of the DB-HE 2013. It also shows the difference between the proposed value and the

optimal value.


28

Table 21. Comparison table for non-renewable primary energy consumption [kWh/m2·an]

Reference building EPnren Difference (%)

Optimal 2013 2018 Optimal in 2018

NEW BUILDINGS (financial analysis, 7%)

N_R05_unif_aislada 46.0 58.4 32.7 -29 %

N_R09_unif 59.8 60.1 32.7 -59 %

N_R02_plurif_entrem 42.1 52.8 32.7 -22 %

N_R07_plurif_aislada 47.2 55.1 32.7 -31 %

N_T01_oficinas_08M 61.7 - 65.0 5 %

N_T02_juzgados_16M 130.2 - 98.3 -25 %

EXISTING BUILDINGS (financial analysis, 10 %)

N_R05_unif_aislada 76.1 - 63.3 -17 %

N_R09_unif 80.8 - 63.3 -22 %

N_R02_plurif_entrem 63.8 - 63.3 -1 %

N_R07_plurif_aislada 76.4 - 63.3 -17 %

N_T01_oficinas_08M 58.6 - 65.0* 11 %

N_T02_juzgados_16M 112.6 - 98.3 -13 %

* Difference obtained for the proposed value in 2018 and the optimal: 100 · (2018 - opt) / opt The values obtained correspond to the energy prices baseline scenario.


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10. Analysis, conclusions and justification of the differences found

As can be seen from Table 23, the proposed levels of energy efficiency (considered as

consumption of non-renewable primary energy) are adequate compared to those obtained in

the optimal cost study, given that they do not exceed the value obtained for the optimal cost -

as laid down in the Energy Performance of Buildings Directive - by more than 15 %.

In addition to the requirements related to the consumption of non-renewable primary energy,

the review of the ‘Energy Saving’ Basic Document (CTE DB-HE) proposed for 2018 sets

additional requirements concerning the total primary energy consumption, the quality of the

thermal envelope, the efficiency of technical systems and the use of renewable energy.

As detailed in the Selection of the regulatory standards section, the limit values for total

primary energy consumption, including the overall thermal transmittance and solar control,

were established on the basis of the optimal cost study, and the minimum levels of

renewable energy use and the efficiency of technical systems were checked against this

study.

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