My husband has inherited a house built in the 1950s that we are looking to renovate. We are trying to figure out how to make it as energy efficient as possible and are willing to spend on this. We’re not really sure where to start and are looking for some advice/resources.
Typically, houses built in the 1950s were solidly constructed of masonry but have little or no insulation, narrow cavity or cavity block walls, single glazing and leak energy, however, the are usually worthy candidates for sustainable renovation and energy efficiency upgrades. It’s important that the original construction is understood and the energy weaknesses are tackled properly to avoid issues sometimes seen in much newer houses.
If recently transferred to your husband’s name, the Building Energy Rating (BER) should have been produced as this is a “transaction” to trigger the requirement and will include suggestions for energy saving based on the ability of the assessor to foresee what potentials exist.
The report is a good starting place for information on energy systems appropriate to the property and will also refer you to the Sustainable Energy Authority of Ireland website (seai.ie). Its Renewable Energy Library contains helpful consumer guides and leaflets.
Extensive renovation may be “material alteration” so you might need to comply with the building regulations including the energy preservation measures prescribed in current Parts F & L technical guidance documents – this can mean engaging with the BCA regulations with a commencement notice.
When apportioning your efforts, first look to the low-hanging fruit of installing additional insulation. Start with the loft, then walls, then the windows and doors. External insulation (EWIS) systems usually are the better solution for walls; grant assistance recognises this but can be prescriptive, so ensure that existing cavities are first pumped and that any new windows are correctly fitted within the new insulation zone.
Improving the heat efficiency of the floor is often difficult, so installing “skirt” insulation linked to external insulation can militate somewhat against cold bridging at skirting level, otherwise floor removal and replacement might be an option.
Acquiring passive solar energy to supplement heating by extending with a conservatory could be considered, subject to planning and orientation. Solar thermal panels can provide a good proportion of hot water but the return on investment will be very long unless you use a lot of hot water at the times when the sun provides the energy – so photovoltaic panels to create electricity are a better way forward, especially if electrical storage systems and heat pumps are used to enhance the benefits.
Heat pumps work from ground, water or air-sourced natural energy, the latter being more popular even with their lower efficiency during cold snaps. Again, see hpa.ie
Heat recovery ventilation systems must also be considered if a healthy air quality is to be maintained, see the Irish Ventilation Industry Association (ivia.ie). My current preference is not to throw any hard-earned energy away with these so-called passive systems by specifying better exhaust air-heat pump ventilation systems. These will leverage all the otherwise wasted energy to sequentially raise the internal house temperature to your set comfort level as well as providing very economical hot water.
Look also to energy-efficient lighting and appliances as well as electrical storage systems that can balance your energy loads especially if you go EV or have a so-called smart metre installed.
Comparing energy systems is not straightforward; each will have strengths and weaknesses depending on the shape of the property, orientation or site as well as your budget. Sometimes you might be best advised to seek independent professional advice.
Fergus Merriman is a chartered building surveyor and member of the Society of Chartered Surveyors Ireland, scsi.ie