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Category: Sustainability (page 1 of 7)

All New Homes Will Be Nearly Zero Energy Buildings (NZEB)

Amendments to Part L of the Building Regulations (relating to the conservation of fuel and energy in dwellings) will come into effect on 01 November 2019.

All new homes will have a typical Building Energy Rating (BER) of A2 and will be 70% more energy efficient and emit 70% less carbon dioxide than 2005 performance levels.

What is a Nearly-Zero Energy Building (NZEB)?

‘Nearly zero-energy building’ means a building that has a very high energy performance. 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.

Are there any exceptions to the new regulations?

Yes, but only if planning approval or permission has been applied for on or before 31st October 2019 and substantial work has been completed by 31st October 2020.

“Substantial work has been completed” means that the structure of the external walls of the dwelling has been erected.

 What are the key changes to TGD L Dwellings 2019?

  • MPEPC (Maximum Permitted Energy Performance Coefficient)=0.30, in order to achieve the acceptable primary energy consumption rate.
  • MPCPC (Maximum Permitted Carbon Performance Coefficient)=0.35, to demonstrate that an acceptable CO2 emission rate has been achieved.
  • Where a dwelling undergoes major renovation, the energy performance of the whole dwelling should be improved to Cost Optimal level insofar as this is technically, functionally and economically feasible.
  • Introduction of a Renewable Energy Ratio (RER) of 20%.
  • Reduction of air permeability backstop from 7m3 /hr/m2 to 5m3 /hr/m2.
  • Table 1- Reduction of wall and floor backstop U-Value from 0.21W/m2K to 0.18 W/m2K.
  • Table 1- Reduction of window backstop U-Value from 1.6 W/m2K to 1.4 W/m2K.
  • Inclusion of guidance to avoid overheating in dwellings.
  • Par 1.3.2.4 – removal of variation of U-Value with percentage glazing.
  • Introduction of calculation of Ru value for corridors in apartments.

How can compliance be achieved?

The correct specifications need to be prepared by your Architect to your specific project. Compliance is then demonstrated using the DEAP (Dwelling Energy Assessment Procedure) software.

Below is an example prepared by the Department of Housing, Planning and Local Government for a semi-detached dwelling with 126 sq.m. and with heat pump for space heating and continuous mechanical extract ventilation.

NZEB example specification
Semi-detached dwelling with 126 sq.m. and with heat pump for space heating and continuous mechanical extract ventilation

A nearly zero energy buildings (NZEB) future – Minister English reminds construction sector to be prepared for new building regulations on energy efficiency

What’s All the Fuss About the Revised Energy Performance of Buildings Directive

Overview of Key Changes to TGD L – Dwellings 2019

What’s All the Fuss About the Revised Energy Performance of Buildings Directive

The amendment of the Energy Performance of Buildings Directive (EPBD) is one of the most important changes that has occurred in the EU buildings sector in the last 16 years.

Under the revised Energy Performance of Buildings Directive (EPBD):

  • EU countries will have to establish stronger long-term renovation strategies, aiming at decarbonising the national building stocks by 2050, and with a solid financial component.
  • A common European scheme for rating the smart readiness of buildings, optional for Member States, will be introduced.
  • Smart technologies will be further promoted, for instance through requirements on the installation of building automation and control systems and on devices that regulate temperature at room level.
  • E-mobility will be supported by introducing minimum requirements for car parks over a certain size and other minimum infrastructure for smaller buildings.
  • EU countries will have to express their national energy performance requirements in ways that allow cross-national comparisons.
  • Health and well-being of building users will be promoted, for instance through an increased consideration of air quality and ventilation.

Other requirements under the Energy Performance of Buildings Directive include:

  • All new buildings must be nearly zero-energy buildings by 31 December 2020.
  • Energy performance certificates must be issued when a building is sold or rented, and they must also be included in all advertisements for the sale or rental of buildings.
  • EU countries must establish inspection schemes for heating and air conditioning systems or put in place measures with equivalent effect.
  • EU countries must set cost-optimal minimum energy performance requirements for new buildings, for the major renovation of existing buildings, and for the replacement or retrofit of building elements (heating and cooling systems, roofs, walls and so on).
  • EU countries must draw up lists of national financial measures to improve the energy efficiency of buildings.

What is the challenge?

  • The Commission reached an agreement that includes a binding energy efficiency target for the EU for 2030 of 32.5%.
  • The risk of the directive being ineffective is high if countries and local authorities do not enforce it correctly.
  • Around 200 million buildings need to be renovated. EU countries must make energy efficient renovations to at least 3% of the total floor area of buildings owned and occupied by central government.
  • EU governments should only purchase buildings which are highly energy efficient.
  • EU countries must draw up long-term national building renovation strategies which can be included in their National Energy Efficiency Action Plans.
  • Member states are to provide for set system requirements in respect to installation, sizing, adjustment and controls. This applies to heating systems, hot water, air conditioning and large ventilation systems.
  • Cost optimal performance – the integration between cost optimality and high performance technical solutions underpins the deployment of NZEBs.

Why Use Ground Source Heat Pumps in Ireland?

 

Ground Source Heat Pumps are an efficient method of harnessing Geothermal Energy. These systems provide significant cost savings compared to fossil fuel alternatives as well as providing environmental benefits.

The image below from Geological Survey of Ireland explains how a ground source heat pump works. How ground source heat pumps work

© Geological Survey of Ireland 2015

 

In Ireland the ground maintains a constant temperature between 11°C and 13°C, several metres below the surface.

 

Ireland has warm moist soils and a climate which is ideally suited for harnessing shallow geothermal energy year round. The soil type in Ireland allows this heat to be retained, while the frequent rainfall keeps the soil moist. This moisture within the ground is an excellent heat conductor, allowing heat to move towards your collector system. This favours the deployment of horizontal collector systems in many parts of Ireland.

(Source © Geological Survey of Ireland 2015, ‘Ground Source Heat’ & ‘Shallow Geothermal Energy’ Homeowner Manual)

There are other types of heat pumps but the earth’s constant temperature is what makes geothermal heat pumps one of the most efficient, comfortable, and quiet heating and cooling technologies available today. The ground ensures a relatively stable supply of heat for the heat pump and higher performances than air-source ones.

What are typical system installation costs?

The installation guide price outlined below is for a 4 bedroom detached property with a BER of C1 and allows for 200 square metres (m2) of underfloor heating. The costs include the cost of the heat pump and the groundworks for the installation of a loop.

Heat pumps Costs 2012

© Geological Survey of Ireland 2015

The initial capital costs of installing a ground source heat pump system is usually higher than other conventional central heating systems. But typically, four units of heat are generated for every unit of electricity used by the heat pump to deliver it, and the payback time is typically about 8-10 years.

Geological Survey of Ireland published in March 2015 a publication that aims to help readers with the decision to purchase and install a domestic ground source heat pump (GSHP) system for home heating. You can download this publication here:  ‘Ground Source Heat’ & ‘Shallow Geothermal Energy’ Homeowner Manual.

GeothermalHomeownerManual_Page_01

The Geological Survey of Ireland has produced a series of ‘ground source heat suitability’ maps. These maps provide a useful preliminary screening tool to assess what type(s) of ground source heat collector system is most appropriate. Separate maps have been produced for horizontal and vertical and closed and open loop systems.

The ground source collector suitability maps can be queried interactively via the GSI’s webmapping at http://www.gsi.ie/Mapping.htm

For more information on the maps and ground source and geothermal resources, please see http://www.gsi.ie/Programmes/Groundwater/Geothermal.htm




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