Nearly Zero Energy Buildings

(NZEB) for Public Sector

Seán Armstrong,

Housing/Building Standards Section,

DHPCLG

Todays Objectives

• Explain the Public Sector Interim Nearly

Zero Energy Building Specification

• To learn how to apply it using

NEAP/SBEM

• To gather feedback on Interim NZEB

Public performance requirements

Outline

• Implementing the Energy Performance of

Buildings Directive

• What are Nearly Zero Energy Buildings

• How does it apply to Public Sector

• Next Steps

Article 9 Requirements include:

• All new buildings to be “Nearly Zero Energy Buildings” by 31st Dec 2020

• New buildings owned and occupied by Public Authorities to be `Nearly

Zero Energy Buildings’ after 31st Dec 2018

• Major Renovations in Building Codes to be at Cost Optimal Level.

Recommendations on NZEB issued by Commission in July 2016

• Member states should take account of “the period of validity of building

permits, the length of construction and completion of building works” to

avoid falling short of the NZEB target dates in the EPBD.

Energy Performance of Buildings Directive (EPBD)

Implementation of EPBD • TGD L Buildings other than Dwellings is currently under review to provide

detailed NZEB guidance and include Major Renovations performance

requirement:

– Public Consultation – 24th February 2017

– Final Publication-Mid 2017

– Application- planned for early 20191

• NZEB Interim Specification for Public Buildings issued 23rd Dec 2016 for

buildings commencing design in early 2017

• SI 4 of 2017 has amended Building Regulations to include the definition

of NZEB

• TGD L Dwellings 2011 has been amended to include NZEB Definition of

an MPEPC of 0.30 and MPCPC of 0.35 for dwellings completed after 31st

Dec 2020

1 Subject to Regulatory Process

EPBD Definition- Nearly Zero

Energy Building

‘nearly zero-energy building’ means a building that has a very high energy performance, as determined in accordance with Annex I. The nearly zero or very low amount of energy required should be covered to a very significant extent by energy from renewable sources, including energy from renewable sources produced on-site or nearby;

RTE PV Array

Commission Recommendation

for offices-July 2016

• Offices

85-100 kWh/(m2.y) of primary energy use

covered by 45 kWh/(m2.y) met by on-site

renewable sources

Public Sector Interim NZEB Specification

• Issued by DHPCLG on 23rd December 2016 to all

Government Departments, Agencies and Local Authorities

• Developed in conjunction with OPW, DES, HSE and SEAI

• Available to download from SEAI website

• Intended to be used until by Public Sector new Part L-

Buildings other than Dwellings applies in early 2019

• Should be used for all buildings owned and occupied by

Public Authorities expected to be completed after 31st Dec

2018

• Detailed guidance on application and Renewables Calculation

tool to be issued in the coming week

Key Components of

performance requirement • Provides an improvement in performance in the

order of 50% to 60% over 2008 TGD L

• Improved Fabric Specification

• Advanced Services and Lighting specification

• Renewable Energy Ratio of 20%

.

Performance requirements for Public Sector

Specification Reference Building-Fabric Parameter Current reference values-TGD

L 2008

Reference values-Public

Sector Specification

Total Floor Area and

Building Volume

Same as actual building Same as actual building

Opening Areas Offices and Shops –windows and

pedestrian doors are 40% of the

total area of exposed walls

Offices and Shops –windows and

pedestrian doors are 40% of the

total area of exposed walls

Walls U=0.27 W/m2K U=0.18 W/m2K

Roofs U=0.16 W/m2K U=0.15 W/m2K

Floor U=0.25 W/m2K U=0.15 W/m2K

Thermal bridging Add 16% to fabric heat loss Actual Length of Key Junctions x

Advanced psi value

Air Permeability 10m3/(hr.m2) 5m3/(hr.m2) Floor area <250m2

3m3/(hr.m2) Floor area >250m2

Window U Value

Solar energy

transmittance

2.2 W/(m2K)

0.72

1.4 W/(m2K)

0.40

Services Parameter Current reference values-

TGD L 2008

Proposed reference

values-TGD L 2017/Public

Sector Specification

Heating efficiency (heating

and hot water)%

0.73 CoP 91% Gas Boiler

Cooling Seasonal Energy

Efficiency Air conditioned

building

Ratio (SEER)

SEER=1.67 SEER=4.5

Lighting divide the illuminance

by 100, then multiply by 3.75

W/m2 per 100 lux

65 lm/circuit watt

Occupancy Control Local Manual Switching Automated

Daylight Control Local Manual Switching Automated

Central Ventilation SFP 2 (W/(l/s)) 1.8 (W/(l/s))

Variable speed control of

fans

No Yes

Renewable Energy Ratio None 20% using photovoltaics

Interim Public Sector Specification-Fabric Backstops

• New Backstops (W/m2K) as for TGD L-Dwellings:

– Pitched Roof 0.16

– Flat roof 0.2

– Walls 0.21

– Floors 0.21

– Windows 1.6

– Curtain walling 0.21

– Vehicle access doors 1.5

• Airtightness Backstop-5m3/(hr.m2)

Checking NZEB using NEAP

• Current version of SBEM 3.5 to be used - available on SEAI website

• Calculate the performance of the proposed building in SBEM using

the draft Interim Public Sector Specification for fabric and services.

This must be done manually using “table 1” from the draft interim

specification with same size and shape as actual building. This then

becomes the reference building.

• Calculate the performance of the proposed building in SBEM using

the actual design specification for the building

• Compare the primary energy (kWh/m2/yr) and carbon dioxide

emissions (kgCO2/m2/yr) between the building with the actual

performance specification and the building modelled with the draft

Interim Public Sector performance specification.

Checking NZEB using NEAP • Where the actual building performance specification has a primary energy

performance equal to, or lower than the primary energy performance

(kWh/m2/yr) of the same building modelled using the draft Interim Public

Sector Specification it achieves the NZEB performance specification for

energy i.e. The Energy Performance Coefficient (EPC) must be equal to or

less than MPEPC =1.0

• Where the actual building performance has a carbon dioxide emissions

performance equal to, or lower than 1.15 times the carbon dioxide

performance (kgCO2/m2/yr) of the building modelled using the draft Interim

Public Sector Specification it achieves the NZEB performance specification

for carbon dioxide emissions. Ie. The Carbon Performance Coeffient (CPC)

Must be equal to or less than MPCPC =1.15

• EPC/CPC Spreadsheet calculation tool to be released on SEAI website in

coming week

• Renewables requirement will be included in TGD L Buildings other than

Dwellings as Renewable Energy Ratio (RER)-20%

• It is recognised that in certain confined situations it may not be possible to

achieve the full 20% RER. In these situations Public Sector Authorities

should provide the optimum proportion of energy from renewable energy

sources that is practically possible.

• In all cases the overall energy performance of the building should be

equivalent to the performance of the building as if the 20% RER had been

achieved.

• Renewable energy sources include Photovoltaics, Heat Pumps (Air source

and ground source), Biomass, Solar Thermal ,Primary Energy Savings

from Combined Heat and Power (CHP), Renewable district heating

• Primary Energy Factor for electricity for calculating RER–the same as

residential 2.19 (3 year forward look)

• Calculation Tool to be provided for RER in coming week

Interim Public Sector Specification RER

Costs • Performance requirements are based on cost optimal

reports published in accordance with EPBD:

http://www.housing.gov.ie/housing/building-

standards/energy-performance-buildings/energy-

performance-buildings

• Table 5.3a of Non Residential Cost Optimal Report

provides Initial Investment Costs for the energy related

costs for different performance levels for 5 buildings.

• Further analysis currently being performed for RIA.

• Consultant appointed for TGD L 2017 and costs will

be available for TGD L Public Consultation-end Feb.

Table 5.3a contd.

TGD L-Draft Major Renovation

proposal • Define as “more than 25% of the surface

area of the building envelope undergoes

renovation”

• Provide menu of measures to bring to cost

optimal:

– Upgrade inefficient heating systems

– Upgrade inefficient cooling systems

– Upgrade inefficient lighting systems

New Build: - Walls 0.13 W/m2K - Windows 0.82W/m2K - Roof 0.11W/m2K - Renewables-Pellet boiler and 938m2 PV

EU Study CT5 Report Selected Examples of NZEB http://www.epbd-ca.eu/wp-content/uploads/2011/05/CT5_Report_Selected_examples_of_NZEBs-final.pdf

Retrofit: -Walls 0.13 W/m2K -Windows 0.80W/m2K -Roof 0.08W/m2K -Renewables:Photovoltaic and geothermal heat pump

New Build -Walls 0.14 W/m2K -Windows 0.78W/m2K -Roof 0.10W/m2K -Renewables:Air source heat pump

Efficiency House Plus with E-mobility in Berlin

Project aim: This pilot building generates its own energy and makes it available to the users and the electric vehicles. Excess energy is fed back into the grid or stored in a battery. An annual positive energy balance is required for primary and final energy use.

Building address: Fasanenstraße 87a, 10623 Berlin

Building type: Residential Non-residential Public New Renovated

X X

Single-family house with 2 floors

Building size: 203 m² useful floor area (AN, with AN=0.32*Vgross), 138 m² living area

Building envelope construction:

The floor, the walls and the roof are made of timber panels filled with up to 52 cm cellulose insulation. The windows have triple glazing. Thermal bridges have been minimised. Photovoltaic modules cover the roof and the façade. All house elements can be separated and moved to another location or be disposed of after the lifetime of the building.

Building envelope U-values:

Wall 0.11 W/m²K

Window 0.70 W/m²K

Roof/ceiling to the attic 0.11 W/m²K

Cellar ceiling/ground slab 0.11 W/m²K Building service systems:

The house is heated by a central heating system with an air-to-water heat pump and floor heating. A balanced mechanical ventilation system with 80 % heat recovery and a building energy management system with touch pads are installed. The PV systems on the roof and facades generate electricity that is used by the building, fed into the grid or stored in a battery. The battery, with a capacity of 40 kWh, is made of 7,250 single second-hand battery cells formerly used in electric cars.

Next Steps • Public Sector Specification

– Public Sector Interim Specification available on SEAI Website

– Detailed guidance and RER calculation tool to be provided in coming

week

– DHPCLG ,OPW,DES ,SEAI and HSE working group to continue to

support specification

• TGD L 2017-Buildings other than dwellings

– Public Consultation of TGD L and Regulatory Impact Assessment by

24th Feb. 2017

– NEAP for TGD L 2017 to go for public consultation simultaneously

– Close of TGD L 2017 Public Consultation Mid-April

– Publication of TGD L by mid 2017

– TGD L 2017 planned to apply by start of 2019 (subject to regulatory

process)

http://www.seai.ie/Your_Building/BER/Non_Domestic_buildings/NZEB-

Commercial-and-Public-Sector/Nearly-Zero-Energy-Buildings.html

It is recognised that in certain confined situations it may not be possible to achieve the full 20% RER. In these situations Public Sector Authorities should provide the optimum proportion of energy from renewable energy sources that is practically possible. In all cases the overall energy performance of the building should be equivalent to the performance of the building as if the 20% RER had been achieved.

www.housing.gov.ie