Frequently Asked Questions
What is Retrofit?
The main purpose of a retrofit is to increase the energy efficiency of a home. There are numerous benefits to a good retrofit which include: reduced fuel use, reduced fuel costs and emissions, improved comfort and health through the alleviation of damp and cold and the introduction of improved air quality, and improved asset value (a good retrofit can add value to your home). By using 'quick fix solutions' such as loft insulation, new glazing, insulation to thermal bridges, and a new combi boiler, a retrofit of this fashion could reduce CO2 emissions by 56%.
What is PAS 2035?
PAS2035 was published in May 2019 by the British Standard Institute. It creates a framework for retrofit that ensures that quality standards are met, works are carried out and completed safely, and that retrofit projects are fit for the future.
Can I make my house Passivhaus?
The Passivhaus standard is not always achievable when retrofitting a property. due to the building design or costs. Therefore, EnerPhit was introduced as a standard based on the Passivhaus design. Enerphit is achieved by either using Passivhaus energy modelling tools or meeting certain U Values for different building components, and can be achieved through incremental changes to the property.
What is solid wall insulation?
Solid wall insulation reduces heat lost through your walls, which accounts for around 20-30% of a home’s heat loss. This can be achieved using External Wall Insulation (EWI) or Internal Wall Insulation (IWI). The key points to both options are:
- EWI is lower risk and less disruptive as very little internal works are required. Therefore, EWI can be cheaper than IWI as replacement features such as skirtings, covings, flooring, and redecoration are not required. Scaffolding is required when installing EWI.
- EWI is subject to planning as the process changes the external image of your home. There are varying options to the external finish, such as render, panelled, or brick slips (brick finish).
- IWI is disruptive but can be installed room-by-room. Planning permission is not required for IWI in this instance.
- As a rule, IWI is only considered when EWI is not a feasible option.
- Both options will require upgrades to your existing ventilation system
What is Suspended Floor Insulation?
Suspended Floor Insulation involves removing the existing flooring and insulating between the floor joists, reducing heat loss through the floor. The simplest approach for insulating suspended timber floors is to lift the existing floorboards and insulate between the floor joists by installing battens or netting to support the insulation. During this process, it is important to use this as an opportunity to assess the ventilation within the floor void, identifying and rectifying any issues that may be present before installing the insulation. Any visible areas of damp on the subfloor may be a result of inadequate ventilation, potentially caused by poor original installation of air vents, the sub floor, or issues that have arisen but gone unnoticed. Ventilation should be continuous from one side of the dwelling to the other (Crossflow).
What is Solar Water Heating?
Solar Water Heating Systems (SWHS) are installed to the roof of a property, with similarities to solar panels, and use energy from the sun to warm water for storage in a hot water cylinder.
Due to the varying amount of solar energy available throughout the year, SWHS will not provide 100% of your hot water, with the difference being made up by your conventional boiler. It is common practice for a new hot water cylinder to be installed when introducing a SWHS.
What is an Air Source Heat Pump?
Air Source Heat Pumps (ASHP) are an energy efficient alternative to traditional heating and hot water systems. They reduce the level of CO2 emissions emitted from a dwelling and can significantly reduce energy bills when compared with oil, LPG or electric heating. However, it is important to note that the fabric of the proposed dwelling should be considered a priority before installing heat pumps. If an Air to Air ASHP is used, these are only capable of providing space heating. Therefore, considerations should be made to determine a more energy efficient system for domestic hot water. Heat pumps emit low levels of heat. This, combined with the need for hot water cylinders to be regularly heated to 55 degrees or above to remove the risk of Legionella, makes heat pumps less efficient for hot water systems. An alternative solution could be to install a solar water heater, or a suitable hot water recovery system.
What is renewable energy?
There are a range of options for renewable energy sources, such as Solar PV, Solar Thermal, Wind Power, and Micro CHP. By introducing a renewable energy system to a building, you are removing, or reducing the electricity supply from 'on-grid' electricity which produces large amounts of carbon during the production process. This is achieved by using natural sources, like solar and wind, within a system that is cable of producing and, with the installation of a storage battery, storing electricity. It is important to note that introducing renewable energy systems should be the last-in-line measure, only to be installed once the building's fabric and building services have been assessed and improved where required.
What is Fabric First?
A 'fabric first' approach aims to install improvement measures to the building's fabric (walls, windows, doors, roof, floors) to reduce heat loss and improve air-tightness, followed by designing efficient and responsive building services that are compatible with the insulation and air-tightness measures. The last step to the 'fabric first' approach is the consideration of renewable energy technologies to reduce carbon emissions and, subsequently, energy bills. The three-step approach starts with the most cost effective measures, followed by more expensive and short lived measures. It is not recommended to start with the introduction of expensive and short-lived renewable energy technologies if heat loss and air leakage from the dwelling has not first been addressed.
Will Retrofit save me money?
In short - Yes. However, although the costs of a retrofit will be off set over time through savings on energy bills, domestic retrofit can be a costly process. Homeowners and landlords will possess different desired outcomes and their priorities will differ to one another. The main priority of a homeowner may be the 'simple payback' period and, although capital costs and the level of disruption of the works may be equally important to both homeowners and landlords, the increase in comfort may not be considered to be a priority to a landlord, whereas the improvement to the SAP rating may appeal due to the attractiveness to prospective renters.
The driving factor of domestic retrofit is to reduce carbon emissions and improve homeowner comfort. You will, subsequently, see a reduction in energy bills. This is a given. But, depending on the proposed measures, Retrofit can be expensive. At Haus Energi, we work to individual clients' budgets and make a difference tailored to you.
How much does Retrofit cost?
There is no simple answer to this. It all depends on the number of measures you are looking to install, their complexity, and any constraints that may affect the process. As a guide, you could look to spend £1,500 for some simple single measures (such as loft insulation), or in excess of £25,000 if you were to Retrofit your entire property. This is why we look at Whole House Retrofit with a Medium-term Retrofit Plan. Domestic retrofit can comprise of either a single, one-off measure which has been selected to best meet the client's needs, or a Medium-Term Retrofit Plan can be implemented, providing a number of retrofit packages to be installed incrementally over 20 to 30 years. The chosen approach will be determined by the client's desired outcomes, energy performance targets and budget, as well as any constraints that may prevent certain measures being implemented, such as the history and construction of the dwelling. A Medium-Term Retrofit Plan is used to spread the costs and level of disruption over a set period.
Email: info@hausenergi.co.uk
Call: 01759 361602
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