I am converting a former workshop/storage garage into a home for a relative. They rely on disability benefit, so ensuring the dwelling is energy efficient and has low running costs is a priority. I was surprised and annoyed to find out that this project does not qualify for any of the Sustainable Energy Authority Ireland (SEAI) grants for energy upgrades because it was not previously occupied as a dwelling. The local council has also indicated that the project is unlikely to qualify for a vacant homes grant because they don’t accept it was previously used as a commercial premises.
This means our budget is very tight and installing a heat pump is not an option for us. Could you suggest cheaper alternatives to heat the property? Could we use solar panels, for instance, to run an electric heating system? Would this work with underfloor heating or with electric radiators?
Would a wood-burning stove or wood-pellet stove be sufficient to heat the house? It is a detached single-storey building located in the centre of a small town. It is 66sq m (710sq ft) in size and is of reasonably modern construction; it was built in the 1980s and has cavity walls. We plan to insulate the building as much as possible and install triple-glazed windows.
This is a problem for many people who have elderly relatives or relatives with a disability who may need greater levels of care. I’m assuming that you already have planning approval for “change of use” and “alterations to an existing structure”, as this is the first requirement before commencing any development project, even one that is going to be of benefit to your relative.
The second statutory requirement is compliance with building regulations, as will be advised in your planning grant documents. Even if only minor modifications are needed, you still need to comply with these regulations. A commencement notice (CN) is required before you can start the job, and even if you decide to “opt out”, there are steps you will need to take before you or your adviser can process the online CN application.
Choosing the “opt out” option effectively means you are electing to remove some of the safeguards of the 2014 Building Control (Amendment) Regulations. By opting out, which is an option for once-off residential builds, you would not be required to lodge statutory undertakings and certificates by a designer, assigned certifier or builder, or to lodge an inspection plan.
In the case of the energy solutions you need, you will be looking for a “target assessment for part L” of the regulations, provided by a registered building energy rating (Ber) assessor. This will provide you with a preliminary Ber that will inform the level of heating you will need and the methodology.
The need for a comfortable level of heating and good air quality for your relative should be shared with the Ber adviser, who will normally gravitate to using standard methods such as underfloor heating and external air-to-water heat pumps, along with a heat-recovery ventilation system and the solar panels you are already steering towards.
The principle of any of this is a “fabric-first approach” because if you invest in better than the standard or regulation U values (the metric of quantifying building energy losses), that investment can be offset against lower cost systems for heating without the need for complex, expensive systems.
Opting for a fabric-first approach will ensure your energy bills will be lower in the long term and, importantly, that the indoor climate can be maintained more evenly. A passive house is one designed to have a heat demand which is as low as is practically achievable, so I would suggest that you carry out a detailed assessment to find out the best way you might achieve a U value of about 0.11W/m2K or near to a “passive house” level.
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Because this is a renovation project, these low-energy-loss solutions might be challenging to achieve without stressing the cold bridges and risking unanticipated outcomes such as condensation, which can lead to mould. If possible, external insulation avoids most of these issues, with some careful detailing noting that 1980s cavities might just be 50mm or 2 inches, which would be insufficient cavity fill to reach U values.
Consider a “warm roof” (where insulation is laid over the rafters) as well as the junctions between floor, ceiling, corners, windows and doors, as it will contribute to having the best possible outcome for your relative.
Heating and ventilation systems have come a long way in the past few years; however, some improved systems have yet to become mainstream here. In Denmark and Germany, in particular, they are retrofitting buildings with double-duct exhaust-air heat-pump systems, which not only provide heating but ventilation and hot water all in one single unit, and are much more economical both to install and run than our currently accepted methods, especially where conversion or retrofit is involved. There are a growing number of such systems available but, as always, beware of the sales talk.
Use of direct-energy heating from solar PV panels is an option but during long, dark winters days it will be problematic even with good fabric, so some form of small heat pump could be your answer; underfloor heating probably won’t be your solution.
[ The debate: Is a heat pump a good investment for your home?Opens in new window ]
It seems that wood-fired heating systems may be phased out in the near future, since burning of any kind detracts from our carbon commitments, so I no longer recommend such solutions.
I am unsure why both the Government and SEAI do not support such laudable initiatives as yours, but I would suggest asking your local authority if other types of grant might be available to assist you.
Getting a professional adviser who is experienced in these types of projects, such as a chartered building surveyor, will ensure you obtain the best possible outcome and avoid the costly and often difficult to rectify mistakes, which I am increasingly asked to remedy after the event.
Fergus Merriman is a chartered building surveyor and a member of the Society of Chartered Surveyors Ireland
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