Construction well placed to help meet greenhouse gas emissions reduction targets
MICHAEL SLEVIN, Director, KSN, writes about how the government’s plans to reduce Ireland’s greenhouse gas emissions by 51% by 2030 will affect the construction sector and what measures can be taken to reduce emissions and improve the energy efficiency of our existing building stock.
When it comes to greenhouse gas (GHG) emissions and the energy usage of Ireland’s built environment, the primary users of energy and contributors to GHG emissions are the residential, commercial and public service sectors. These are significant final energy users and are therefore a crucial focus for GHG emissions reductions in the government’s Climate Action Plan. Figure 1 below shows the GHG emissions by sector in 2020, while Figure 2 below shows the final energy usage by sector for 2019.
When looking at the energy usage in the built environment, we also need to consider the energy/carbon required to construct buildings and their associated materials. This is considered later in this article.
Figure 1. (Source: EPA).
Figure 2. (Source: SEAI).
Ireland’s Building Retrofit Programme
Ireland’s ambitions to improve the energy efficiency and renewable contribution of buildings has been ongoing for over 20 years with step by step iterations of EU targets, Energy Performance of Buildings Directive (EPBD) improvements, building regulations and various other regulations and innovations. However, it is the recent Climate Action Plan 2019 and Climate Action and Low Carbon Development (Amendment) Bill 2021 that demonstrate a firm commitment by the government to achieve tangible results for Ireland.
The new Climate Action Bill provides a framework for Ireland to reduce GHG emissions by 51% by 2030 and become independent in energy production by 2050. It is ironic that 100 years ago, 1921, during the coal strike in England and Wales that calls went out for Ireland to become fuel independent. Now in 2021, there is a real opportunity to achieve this.
The main characteristics of the Climate Action Plan with regard to the built environment include the following key actions by 2030.
- 7% per annum reduction in overall GHG emissions from 2021 to 2030 (a 51% reduction over the decade) and achieving net-zero emissions by 2050.
- Retrofitting of existing homes reaching over 500,000 by 2030 to minimum BER B2 standard, as part of the EU Renovation Wave strategy.
- Homeowners to generate their own electricity and sell it back to the grid under a scheme for micro-generation
- 600,000 heat pumps installed (400,000 in existing buildings)
- Improve the energy efficiency of public sector buildings by 50% by 2030 – to BER B ratings
- One-third of commercial (including mixed-use) buildings to have a B BER (or carbon equivalent gains) by 2030
- Ensure a suitable policy framework is in place to support district heating.
A big part of upgrading Ireland’s domestic housing stock provides a huge opportunity to solve the energy poverty crisis. Energy poverty is an inability to light or heat one’s home to an adequate degree, and it currently affects around 17% of Irish households. Within the government’s Climate Action Plan, a strategy to deal with energy poverty is correctly identified and aims to alleviate the burden on the most vulnerable in society through actions focused on improving the efficiency of homes, supporting lower-income households with their energy costs and minimising the costs associated with action on climate change. In this regard, several government initiatives focus on upgrading these homes and reducing the levels of fuel poverty.
Upgrading Ireland’s existing residential stock
For this article, I have outlined below common steps available to upgrade an older residential property to achieve a BER rating of A or I have set out indicative costs of carrying out such a retrofit in Table 1.
The main principles of upgrading a home have a few basic rules.
- Step 1: Fabric first approach – You should always aim to insulate the envelope of a home first through roof, wall and floor insulation, windows and doors. This approach will improve airtightness, benefit the comfort levels in a home and reduce heating requirements. The easiest energy saved in a home is that not used.
- Step 2: An air permeability of 5m3/h/ m2@50pa or less is desirable to achieve a high performing home suitable for heat pump installation. Along with this level of airtightness, a clear ventilation strategy shall be required and can generally be achieved through a demand control ventilation (DCV), centralised continuous mechanical extract ventilation (CMEV) or mechanical ventilation heat recovery (MVHR) system.
- Step 3: The heating centre of a home should be through a heat pump to avoid using fossil fuels and future proof the home for the greening of the national grid in 2030.
- Step 4: Install a renewable energy source to provide renewable energy and meet Part L building regulation requirements. All works should be designed by a competent designer (technical assessor) and fitted in accordance with current building regulations.
Note: Costs outlined in Table 1 provide a guide on upgrading each property type to A-rating with heat pump installation; VAT is included; excludes any grants or energy credits available; not all upgrade measures are suitable or required to an individual property; each house type should be reviewed by a component designer and specified in accordance with building regulations.
Dealing with the embodied carbon in constructing buildings
Energy efficiency in the running of buildings has been well developed over the past 10 years, and most people in the industry understand the ratings and terminology associated with energy certificates such as BER rating, Leadership in Energy and Environmental Design (LEED), etc. The next step for the industry to challenge is to reduce the amount of carbon in building construction and building products, ie, embodied carbon and the life cycle carbon of buildings. This is more important now with our new buildings run efficiently, the larger proportion of carbon is mainly produced in the construction.
Importance of embodied carbon as buildings become more efficient
Embodied carbon is beginning to receive more attention from developers, designers, investors, contractors and product manufacturers. The long-term goal is to construct buildings in materials that have required zero carbon to create, install and recycle. To do this, we need to know how to measure and design buildings with new products and methods of construction that enable us to tackle the embodied carbon in buildings. This, in turn, provides a great opportunity for members of the development process to set targets, design and construct in innovative ways and with more sustainable products. Ten years ago, we looked at the operational ratings of our buildings. Now we need to benchmark and rate the construction of our buildings.
Michael Slevin is a director of KSN and manages KSN Energy – A bespoke retrofit and sustainability service for the construction industry – that he jointly founded in 2009.
KSN is one of Ireland’s leading construction consultancy practices, providing cost management, sustainability management, project management and a number of expert support services to both public and private clients. In 2010, the directors of KSN founded KSN Energy, which focuses on providing bespoke retrofit and sustainability services for the property sector. Over the past 10 years, KSN Energy has developed its team to provide a one-stop-shop that can assist in the retrofitting and upgrading of properties on a significant scale. The services provided include energy auditing and building energy ratings (BERs), project management, quality control, energy credit verification, site conformance inspections, product specification development and other energy-related services.
To date, KSN Energy has managed the upgrade of numerous domestic and commercial properties so that energy usage is reduced to current upgraded retrofit standards, ensuring optimum insulation levels are achieved, renewable technologies are installed, and occupant comfort levels are improved with healthy environments.
- 65-member energy team
- 65,000 property upgrades managed
- 60,000 quality assurance inspections completed
- 45,000 BER certificates issued
- 7,000 BER audits completed
- 1,200 GWh (300 projects) audited.
If you would like to learn more about the work of KSN Energy, visit www.ksn.ie