Renova-Custom-Home-Retro-Fits-John-Martin and Alan Stevens-90

Stoves have now become the stylish and energy-efficient alternative to the open fire for many Irish people. As well as lowering fuel bills, stoves looks great. There’s no denying the cosy and comforting feeling that a stove will bring to any home.

Energy efficiency is the main advantage of stoves. Only about 25 per cent of the heat generated by an open fire actually ends up in the room – the rest of it escapes up the chimney. In contrast, stoves are about 80 per cent efficient, and if burning wood, are better for the environment. Stoves also help to eliminate draughts as they seal in the chimney flue, thus eliminating ‘up draught’ which draws draughts into your home.


Wood-burning stoves are only capable of burning wood and wood derived fuel, like wood pellets. They generally consist of a cast iron or steel closed fire chamber, a brick base and an adjustable air control.  They do not have a fixed grate because wood and wood pellets burn very effectively on a bed of their own ashes. This results in greater efficiency and heat output. Also, as these stoves only burn wood and biomass fuels which are renewable, they are eco-friendly. Wood burning is regarded as a carbon neutral form of energy because during its growth, a tree will absorb roughly the same amount of carbon dioxide as it emits when it is burned. Wood ash is also good for planting and gardening. Therefore, as a provider of ‘green’ heat, a wood-burning stove is required in order to reach passive house standards. A disadvantage of wood-burning stoves, however, is that you will need somewhere to store the wood, as dry wood is delivered in large quantities. This could be a problem in suburban areas where garden sizes are small.


Multi-fuel stoves are also typically made of cast iron or steel. They include a grate with an ash pan beneath to collect the ashes, which maintains effective combustion. As a result, it is possible to burn a variety of materials instead of just wood. However, because they are capable of burning coal, briquettes and other non-renewable fossil fuels, they are not certified under new green building regulations. Many people choose to only burn wood in their multi-fuel stove which is also a viable and eco-friendly option.

Some multi-fuel models are also boiler stoves (wet stoves), with an attached water tank to provide hot water. They can be connected to the heating system to add heat to a house. A boiler stove will use up a lot more fuel than a dry stove and is dependent upon someone being there all day to feed it. Dry stoves are easier to put in as they don’t have to be connected to the heating system. At RENOVA we do not generally recommend the installation of boiler stoves.




Air Supply is important for the safe and efficient operation of stoves. Fresh air needs to enter to provide oxygen fuel for the fire. To regulate air flow, there are damper devices built into the stove. The dampers can usually be accessed by turning a knob or a handle attached to the damper, found outside the stove. Except when helping the chimney/flue to heat up initially, it is not recommended to leave the air control fully open. If fully open, more heat is sent straight up the chimney instead of into the room (which reduces efficiency). The biggest problem with leaving it fully open is “overfiring”. This is when too much heat is generated within the fire chamber, which can lead to warping, buckling and can damage the stove and its internal components.


Regarding fuel, the best woods to burn in a stove are oak, ash and beech. They should be well-seasoned (dry) and cut small enough to fit into the stove. Freshly cut wood (known as green wood) has a high moisture content which will result in a lower heat output. It will also cause creosote which in turn causes soot and therefore reduced airflow within the chimney. This can be dangerous as chimney soot can be ignited by rising embers, causing a chimney fire. For best results, firewood should have a moisture content of less than 20%. Even when well-ventilated and covered, seasoning by air-drying can take up to two years. Some companies are now using large kilns to quickly dry their wood.

Both hardwood and softwood have the same energy content and produce similar energy. The main difference is the rate at which the fuel burns. Hardwoods come from slow-growing trees like oak and ash and burn at a slower rate, resulting in sustained output and a consistent temperature. Softwoods are from fast-growing evergreen trees like conifers and burn at a far faster rate. A disadvantage of softwood is that it creates more soot and other deposits on the inside of the wood stove, chimney, and flue. Hardwood and softwood may be used together by adding hardwood on top of softwood that is already lit. Softwood can also be used as kindling to help start the fire.


Safety is important; a stove requires regular maintenance such as emptying ash pans and routine cleaning of the stove pipes and chimney to prevent chimney fires. The basic principle of controlling combustion by reducing the air supply means that carbon dioxide is often “reduced” to carbon monoxide within the stove. This gas is highly poisonous. It can occur if the stove or chimney has not been cleaned or if there is insufficient ventilation. Carbon monoxide detectors should always be installed where a wood stove is in use.

carbon monoxide detector


A  stove typically costs from €1,500 for a cheaper model to €8,000 for a larger ‘designer’ stove. These costs generally include supply and installation but always ask your supplier if the flue, hearth and labour costs are included in the final price. There’s no question too that wood is cheaper than other fuels. According to the SEAI, the delivered energy cost from wood per kWh is about 20% less than natural gas and is significantly less than electricity. If you have a wood supply available to you, this means little to no cost.shutterstock_74850409 resized



To to find out more about heating and for a free, no obligation consultation, call RENOVA today.

Click here to download our RE NOVA brochure.

Tel: 01 2021122



Heating – a glossary of terms


Heat Pump

This is an alternative to a boiler. It sources low temperature heat from the air, the earth or ground water. Using electricity, it ‘pumps it up’ to a higher temperature for use in a heating system.

1. Air to Water Heat Pump


A heat pump which uses a fan to take in air from outside. It extracts low temperature heat from this air to generate heat for a heating system.

2. Ground Source Heat Pump



A heat pump which extracts low temperature heat from the earth. These images show how heat can be extracted through a system of pipes laid horizontally in the ground or from the earth through a bore hole or well. 

Heating Controls

Heating Controls

A modern version of the old ‘time clock’ – a sophisticated combination of devices which controls when the heating system switches on and off.


Thermostats are devices which determine air or water temperature within a heating system.

In a home they are located within hot water cylinders, boilers and rooms (room stat – see below).

Room Stat

‘Stat’ is an abbreviation of ‘thermostat’. These are small devices placed around your home which can detect the temperature in a room. They can be set to any temperature and can ‘switch off’ or ‘turn on’ the heating automatically to maintain rooms at a particular temperature. Thermostats feed information to heating controls systems. They ensure that your heating system is used as efficiently as possible.

Condensing Boiler

Condensing Boiler

These look and operate like conventional boilers but are more efficient because they extract heat from the exhaust fumes which ordinary boilers do not do. Condensing boilers are recognisable by plumes of condensation being emitted from the flue when operating.

Rads (Radiators)


A commonly used term for radiators.

Solar Panels

solar panel

A flat panel or group of tubes which are exposed to the sun’s energy, normally on a roof. They contain special fluid which heats up and circulates through the hot water cylinder in a house to heat water.

Solar panels can also be Photovoltaic meaning that they generate electricity for use in the home. Although less common they are becoming more popular in recent years.

Under Floor Heating

underfloor heating 070306001med

A system of pipes laid under a floor to heat a house. Hot water flows through these pipes to warm up the floor. The floor effectively becomes a giant radiator. The water in the pipes can be heated by a boiler or a heat pump.



‘Thermostatic Radiator Valves’. A relatively primitive form of thermostat fixed directly to the valves on a radiator. They automatically switch a radiator off when a predetermined temperature has been reached.

If you want to find out more about heating and for a free, no obligation consultation, call RENOVA today.

Click here to download our RENOVA brochure.

Tel: 01 2021122




Ventilation in your Home – a glossary of terms by RENOVA

 Air Changes per Hour (ACH)

Ventilation image 1

 Air changes per hour (ACH or ac/h), is a measure of the air volume added to or removed from a space, divided by the volume of the space. Simply put, ACH is the rate at which a space is ventilated. Certain places will require more air changes per hour, depending on usage and occupancy – for instance kitchens and bathrooms where there tends to be a high moisture content.




Ducting for Ventilation

Ducting is pipework through which air is channelled in a ventilation system. It is normally concealed behind walls and above ceilings.


Natural Ventilation

passive ventilation

This is a basic form of ventilation which relies on ‘holes in the walls’ and is very common in most Irish homes. Incoming and outgoing air will vary depending on wind speed and wind direction. This can result in unwanted draughts at times and therefore is far from ideal.


 Demand Controlled Ventilation (DCV) 

aeroco mechanical ventilation

Above is an image from aereco which illustrates how DCV operates. ‘Demand Controlled Ventilation’ (DCV), is a system which provides constant ventilation within a house. It links the amount of fresh air entering the building to the occupancy levels of a building. Energy savings are made when the need for ventilation is low, which can represent over half of the time. This system adjusts the amount of incoming fresh air based on humidity levels in the house, and therefore the need for replacement air. For example, if there is a lot of indoor air pollution from cooking, showering etc, then a greater airflow is generated to remove it efficiently.


Mechanical Ventilation with Heat Recovery (MVHR)

MVHR Image

‘Mechanical Ventilation with Heat Recovery’  (MVHR) is a system which also provides constant fresh air within a home. The fans are ‘controlled’ so the ventilation is ‘mechanical’ as opposed to natural. Simply put, a fan draws fresh air into a building and distributes it via ducts, and other ducts draw stale air out. By using a ‘Heat Exchanger’ at the fan, fresh cold outdoor air is warmed up to a comfortable temperature by using the heat of the warm, stale indoor air as it is extracted. There is no pollution or contamination from the stale air – only the heat is exchanged. 


 Positive Pressure Ventilation

positive pressure ventilation

With ‘Positive Pressure Ventilation’, a centrally located fan provides a constant stream of fresh air within the house. This air finds its way out through vents and other ‘gaps’ in the fabric of the building. In doing so, unwanted draughts are prevented from entering the house. 


Blower Door Test

Blower door test

Above is an image of a Blower Door Test carried out during a RENOVA retrofit.  A Blower Door Test is an air pressure test undertaken at the end of a job to check for air leakage and to eliminate any draughts. The results provide a certified air tightness result.


If you want to find out more about ventilation and for a free, no obligation consultation, call RENOVA today.

Click here to download our RENOVA brochure.

Tel: 01 2021122



RENOVA at the Ideal Home Show

 “Few things in life are as important to us as our homes. ‘Home’ is where we spend most of our time. It’s a place where we can relax, unwind and feel comfortable and secure. ‘Home’ is where we can escape from a busy and often crazy world! We should enjoy living in our homes, be proud of our homes, we should ‘Love’ our homes…” – RENOVA

Ideal Home Show

At our recent exhibition at the Ideal Home Show in the RDS in Dublin, we were thrilled to receive such a positive and enthusiastic response to our Deep Retrofit and Renovation service. Indeed, the public’s positive reaction re-affirms our budget-led, energy-aware and stress-free approach to renovations.

It was fantastic to see a growing public awareness of Deep Retrofit and energy efficient renovations. Our exhibition stand said it simply – ‘Love Your Home Again!’ and outlined the fundamentals of Deep Retrofit. It showed how, at RENOVA, we transform your home into the best place it can be. We do this through; Insulation, Air-tightness, Windows & Doors, Heating Systems, Lighting, Ventilation and Interior Design. By ‘Thinking Deeper’ it really is possible to create a home that is not only energy-smart but smart to look at too. This is the reason we are so different to other retrofit companies – we offer a complete 360 degree, turnkey service. We renovate while you relax!

We were delighted to meet with so many enthusiastic people at the Ideal Home Show who are thinking about carrying out a home renovation through Deep Retrofit. Some people had recently bought an older home that needs to be upgraded whilst others were thinking about purchasing a doer-upper. There were many older people who were thinking of down-sizing.  And of course, those who have been living for far too long in a cold and draughty home and want to optimise their living environment by making it comfortable, warm and energy-efficient. We were very happy to take a look at the plans and brochures they brought along, answer questions and offer advice on the multiple components of Deep Retrofit and renovations.

Through Deep Retrofit, homes can be brought up to passivhaus standards with air-tightness, good insulation and high-performance glazing. A retrofitted home is warm both day and night, with minimal heating. It will also be cooler during hot summer weather. Hot summer weather which seems to be becoming more common in recent years, perhaps as a result of global warming.

At RENOVA we upgrade your home from the inside out. This means that we address the basic principles of warmth, fresh healthy air, sound insulation and energy efficiency first. Then we make sure that your home functions for you as a space and that it looks good too. It’s true after all that the environment in which we live has a very big impact upon not only our physical health, but our mental health too. Therefore, we believe that ‘Deep Retrofit’ is a very worthwhile and rewarding business as it improves the quality of people’s lives. Not only that, it is good for the environment too! It is a crucial part of a low-emission future and is a way in which we can improve the future for our children. For all of these positive reasons, spreading the word about ‘Deep Retrofit’ has become our passion in life!Ideal Home Show

Reducing energy use, costs and greenhouse gas emissions has become very topical in the past number of years. Because of this there are now grants available from the SEAI for homeowners who invest in energy improvements in one or more of the following areas;

  1. Roof Insulation
  2. Wall Insulation
  3. Installation of a High Efficiency (>90%) Gas/Oil fired Boiler
  4. Heating Control Upgrades
  5. Solar panels


You can also save up to €4,050 in tax or 13.5% of the cost of your project (up to a limit of €30,000) on a wide range of home improvements and renovations under the Home Renovation Incentive Scheme.


Call us today to start your journey with RENOVA!

Click here to download our RENOVA brochure.



Tel: 01 2021122




Ventilation, Air-Tightness & Insulation


A well-retrofitted home by RENOVA will not only be completely air-tight and well-sealed; most importantly it will be well-ventilated. It’s a simple fact that air-tightness and ventilation should go hand-in-hand to prevent an unhealthy living environment.

In the past, although we lived in draughty homes which were difficult to heat, they were usually well-ventilated. They were well-ventilated as a direct result of their draughtiness. Believe it or not, this was actually healthy – healthier at least than living in a well-sealed yet badly ventilated home which unfortunately we are seeing a lot more of these days. The old rattly windows and doors, badly/uninsulated walls, floors and attics were, in fact, performing two very important roles: allowing the house to breathe whilst letting the heat and moisture out.


Leading on from this, nowadays here in Ireland, in our more modern homes, we still tend to think that by opening a window or a door, all of our heat will escape, along with our hard-earned money! Some of us are even inclined to block up the air vents in the belief that we will be preserving heat, eliminating draughts and protecting ourselves from impending illnesses such and cold and ‘flu. However, the opposite is actually true – blocking up vents and not opening windows means
that moist air cannot escape which causes condensation to form and ultimately mould to grow. Another point to add is never to block an air vent by building a wardrobe in front of it. Damp manifests itself in wet patches, mould growth and a musty smell. Even if the walls are dry-lined (insulated on the inside) humid air can condense behind the insulation, causing a condition known as ‘interstitial condensation’. This occurs when dry-lining is installed incorrectly. This again encourages mould growth and is a difficult and costly problem to eradicate.

Good ventilation requires maintaining a constant flow of air within a house – fresh, clean air in, stale and moisture-laden air out. Good ventilation will remove the humid air before it has a chance to condense on cold surfaces which as we know, creates condensation and mould growth. If left untreated, damp can lead to a host of problems such as corrosion of internal finishes and even health problems, especially in vulnerable young children, elderly people and people with respiratory problems like asthma. Fresh air should constantly be flowing into our homes. Stale, moisture-laden air which is also full of unwanted gases such as C02 and Carbon monoxide and germs, should be flowing out. By eliminating stale, moisture-laden air and breathing in fresh, pure air you will notice a big improvement in your own and your family’s health. Hopefully you will even have fewer trips to see the doctor!

Over the past number of years here at RENOVA we have noticed a recurring theme of enquiry from home owners. Again –  high levels of humidity which is causing both condensation and black mould growth on external walls and ceilings. Fitting new windows, for example and having a more air-tight home without considering ventilation and allowing the house to ‘breathe’ has become the main cause of poor air quality and ‘sick building syndrome’. High levels of humidity need two ingredients to thrive: high temperatures and a supply of water vapour. As a rule of  thumb, humidity levels will double with every 10 degree increase in temperature. In other words, the warmer your house is, the more water vapour the air will hold. As your house becomes warmer, stale humid air is trapped inside. Think of all that moisture building up from showers, baths, kettles, bubbling pots and pans, steamers, tumble driers and of course, our own breathing!

Whilst passive/natural ventilation (holes in external walls) may meet building regulations, it is now widely recommended that controlled/mechanical ventilation is used to maintain a consistent flow of fresh air within the home. There are many sophisticated systems available such as ‘Heat Recovery Ventilation’. However, this can be expensive and difficult to install, especially in a retrofit situation. A cost-effective and practical alternative is an ‘Aereco Demand Controlled Ventilation’ system. Click here to see an Aereco video.

Aereco fan

DCV or ‘Demand Controlled Ventilation’ is based on the simple principle of having the optimum amount of fresh air in a home on a fully automated basis. It offers the ideal solution for both heating consumption and the quality of indoor air. When the need for ventilation is low, which is usually more than half of the time, savings can be made. More ventilation will be needed during times such as showering and cooking, when more moisture and humidity is created. Scientific studies have shown that DCV can result in a 30% reduction in ventilation losses compared to natural ventilation. Here is a photo of the inner workings of an Aereco fan similar to one we recently installed in a house that was suffering with excessive condensation and mould growth. The new Demand Controlled Ventilation system has yielded great results with improved air quality and the elimination of condensation and mould.

We hope that this introduction to ventilation has helped you to understand just how important a good ventilation system is, in particular in relation to our more modern, well-sealed and energy-efficient homes. If you can’t install a Demand Controlled Ventilation system, at least unblock those vents in your external walls and try to open your windows on a more regular basis – it will do your general health and well-being the world of good!


Remember – ‘Build Tight – Ventilate Right!’





Click here to download our RENOVA brochure.



Tel: 01 2021122



Why Older Homes are less Energy Efficient

Older houses are much less energy efficient and less comfortable than modern, energy efficient homes….

As a general rule it costs about 3 times as much to heat a 1980’s house as opposed to an energy efficient modern house. Even then they are still draughty and miserable.  The good news is that any older home can be improved to be as good as an energy efficient modern home, through Deep Retrofit. So don’t be afraid to buy an older home, but do make yourself aware of what you need to do to improve it, and what this will cost before committing to a purchase. To understand the potential of that run down old house you should first of all get an understanding of the many reasons why older homes are not energy efficient:

Insulation – and the lack of it …

This is the major problem in older homes. Heat is generated, put into our homes … and it immediately escapes, so we need to generate more heat, and so on and so on …

In order to be more energy-efficient, our homes need be insulated in three different areas – the external walls, the ground floor and roof/attic. By and large the levels of insulation in older houses is hopelessly inadequate or worse still it is non-existent . Many of these older homes have no wall insulation at all. Homes that do have it are insulated to a very poor standard. Newer homes may be insulated, but unfortunately also to a very low level. This is often poorly installed, meaning they are far from being energy efficient. These houses are often insulated within the cavity between 2 skins of blockwork external walls. The major problem with this cavity wall insulation is that it was installed during the build by block-layers. Unfortunately, they didn’t have any consideration about the home owners’ future comfort or about making the home energy efficient. When you think about it, getting a block-layer to insulate your house ‘while he’s at it, laying blocks’ is no way to insulate a house. Yet, this is the way it has been done for years. This photo shows poorly installed cavity wall insulation installed by block-layers. We uncovered this on a recent renovation. This standard of workmanship is typical rather than unusual.

Poor Insulation

Poorly installed insulation


No insulation underneath the ground floor is another problem which makes older homes less energy efficient. Particularly in relation to houses with suspended timber ground floors. On average 7 – 10% of heat escapes through an uninsulated floor, but worse still, coldness enters our homes through the floor and draughts whip up through unsealed floor boards. No wonder it’s cold and less energy efficient in a house with nothing at all between you and the cold earth beneath. In an era of rising fuel costs and awareness, it is hard to believe that so many people still live in homes like this in the year 2015! This ground floor arrangement is common place and people don’t realise just how bad it is – carpet covers a multitude. Take a look at the photo here to see a before and after in one of our recent renovations. This situation occurred in a beautiful Victorian house in South Dublin. No wonder the house was so draughty!

Original Floor showing no insulation               No Insulation                          

  Insulated floor part of energy efficient upgrade worksAfter – Insulation installed between joists              


With regard to attic insulation, the acceptable thickness for attic insulation just 10 years ago was 100mm. Today, the minimum is 300mm thickness. Unless you’ve had your insulation upgraded in the last few years, chances are you are living under a couple of inches of ill-fitting attic insulation, which renders your home less energy efficient. As approximately 30% of the heat in a home escapes through the roof, attic insulation is of utmost importance. To make matters worse, the typical old ‘attic hatch’ is a weak point too, as it allows heat to escape and draughts to flow in. Sometimes these even ‘flap in the wind’ on a windy night. Replace this with an insulated draught-proof attic door to make your home more energy efficient.


Old windows & doors … heat escaping and draughts getting in.

Rattly old windows and doors are another very common feature of older, less energy efficient houses. Even relatively ‘modern’ windows have poor U-values and draught seals compared to good quality, modern ones. The U-Value of a window represents the degree to which a window retains heat, so the lower the U-Value, the better the window. Approx 15% of heat escapes through bad quality windows and doors. Install energy efficient windows with a uValue of 1.0 or less to fix this problem.


Old appliances and lighting

Believe it or not, the energy required to light an older home can be 80% higher than lighting a modern home with energy efficient lights. All you have to do is replace incandescent bulbs with energy efficient LED lighting to save up to 80% of the cost of lighting your home. Also, the ambiance and atmosphere of your home can be greatly enhanced with the clever use of bulb and lamp types. Likewise, by replacing household appliances with new, energy-efficient A or B rated ones, running costs can be reduced by 50%.


Open fires … money up the chimney!

Open fires are the norm in an older home, and very often there are several. They are not energy efficient and are a significant cause of draught. Open fires can be as low as 15% efficient, meaning that 85% of the heat generated is lost up the chimney! A stove, in comparison is more than 80% energy efficient. A stove will also help to eliminate draughts as it will seal in the chimney flue, thus minimising ‘up draught’ which draws draughts into your home. A ‘room sealed’ stove will completely eliminate ‘up-draught’.


Inefficient Heating Systems

Old boilers are not energy efficient. Typically, just 65% or less of the energy in the oil burned in an older boiler is transferred into heat in the house. This means that 35% of energy purchased in the form of fuel is just wasted. Or, 35c in every Euro spent is wasted. By comparison, modern condensing boilers are 95% energy efficient, meaning that 95% of the energy is converted into heat in your home.

To make matters worse older homes tend not to have ‘heating controls’ so there is only one heating circuit for the whole house, making a typical older home less energy-efficient. This means that the whole house is heated even if just part of the house is in use. Installing heating controls reduces the amount of heat used in the home, which in turn saves money. By choosing to heat only the rooms/floor levels you are actually using and by using a thermostat to control the temperature, you can save money on heating bills and use energy more energy efficient way.

The solution to all of these inadequacies lies in ‘Deep Retrofit’, the complete upgrade of the fabric of your building.

And the easiest way to make your home more energy efficient is to procure that Deep Retrofit by RENOVA – a reputable custom home retrofit and renovations company that will oversee the whole project from start to finish and ease any stresses along the way! So go ahead and buy that house, just make sure you speak to RENOVA first.


Click here to download our RENOVA brochure.





Tel: 01 2021122