LOW ENERGY DESIGN
Low Energy Design:
If you want to build a sustainable new home, the best route to achieving your low-energy goals is by taking a fabric-first approach to design and construction. At NZES, we embrace the use of low energy design techniques and work closely with other building designers to find ways of treating external solar gains outside the building envelope and to make sure that buildings are oriented to maximise winter sun and minimise summer heat. These proven strategies can dramatically reduce a building’s energy consumption for little or no added cost while improving its comfort, economy, and environmental performance.
How does a Low Energy Building work?
Low energy design aims to reduce energy use as much as possible. The basic principles of a low energy building are based on simple building physics;
- Heat losses through walls, floors, roofs, thermal bridges and windows are minimised.
- Air tightness resulting in no uncontrolled heat leaking to outside.
- A ventilation system resulting in fresh air coming into the house and removing contaminants from the internal environment.
- Windows orientated to maximise solar gain without the result in overheating.
- Taking account of internal heat gains from people and appliances that will be retained in the building.
Abiding to these principles will result in a building with clean fresh air, little or no heating costs, no drafts and consistent comfortable temperatures no matter the weather conditions.
What the Performance Gap is and when it occurs?
The “Performance Gap” consists in the difference between how a building is designed to perform and how it subsequently does once built. An overview of the relevance of this significant issue for the construction sector is provided by the extensive collection of academic studies, research and industry reports. Studies have examined the operational energy use and the finding reported energy use was up to five times higher than estimated during design and when comparisons were made with relevant industry benchmark, three quarters of case study designs did not perform as well as expected.
What is the NZEB standard?
The European Energy Performance of Buildings Directive Recast 2010 (EPBD) requires all new buildings to be Nearly Zero Energy Buildings (NZEB) by 31st December 2020 and all buildings acquired by public bodies by 31st December 2018. This means that any buildings completed after these dates should achieve the standard irrespective of when they were started. This is quite different to the transitional arrangements for previous building regulations revisions. ‘Nearly Zero – Energy Buildings’ means a building that has a very high energy performance and in which “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“. At NZES we can guide you through your legal requirements under these regulations.
What Skills are needed for the NZEB standard?
There may be a steep learning curve to achieve the improved standards if professionals have not already upskilled. Demonstrating compliance will become more technical and in fact a science. Design teams need to develop understanding of the software to demonstrate compliance, though more guidance from Government is still required. Achieving higher level improvements will require greater integrated design team working at an earlier design stage. The emphasis on the fabric of the building, will need more in-depth understanding of designing for solar shading, thermal bridge free construction, air tightness and glazing ratios and greater knowledge is required around more efficient lighting, services and renewables. With NZES qualifications and experience, we can provide all the skills required to complete your project.
Deep Retrofit
It is universally accepted that the most important pathway towards low-carbon housing involves deep retrofitting of existing housing stock: it is envisaged that €35 billion investment in existing housing stock will be required by 2050. A Deep Retrofit involves carrying out multiple energy upgrade measures that will deliver a BER rating of A-rated building. Deep Retrofit works are carried out on a whole-house basis and include a combination of measures such as wall & roof insulation, upgrading of windows & doors, air-tightness, installation of ventilation systems and of renewable energy systems. All works and project management should be carried out by suitably qualified and experienced service providers. There are many benefits of carrying out such a retrofit including:
- Increased comfort.
- Improved health and well-being.
- Reduced energy and maintenance costs.
- Reduced carbon emissions.