Energy Efficiency

Deep Retrofitting Our Home

What is a Deep Retrofit

Deep retrofits are a way of improving the energy performance of older building. Our home was originally built in the 1970 and on Ireland Building Efficiency Rating it scored a D2 (on a scale from A1 to G). This meant that our home required a significant amount of energy to heat and most of that energy would just leak out through the walls and roof to the atmosphere.

From date of purchase both Nishta and I were determined to improve our houses energy performance as much as possible. This would entail:

Removing the floors to add underfloor insulation
Replacing the oil heating with a more efficient alternative
Replacing the windows with triple glazing
Wrapping the external walls in new insulation
Improving ventilation
Adding a new super insulated hot water tank
Adding a solar system with battery storage

Our Deep Retrofit was completed by House2Home (bar the solar which will be completed post COVID lockdown) and was supported by a sizeable grant from the SEAI. We highly recommend you look into grants before starting a deep retrofit. These are large and costly projects (ours cost a six figure sum even after the grant!) so any support you can get you should take. At least in Ireland your main contractor should be able to guide you though or will manage the grant process on your behalf.

We chose House2Home because their quote was the most comprehensive and was well laid out in an itemised way. The supplier they were bidding against we felt were more interested in the SEAI and meeting their deadlines than giving us our dream home; so we selected House2Home despite them not always being the cheapest option.

Overall we were very happy with their service and quality of work. The project plan they gave us on day 1 (of what would happen when) went out the window almost straightaway and they weren't always the most forthcoming with granular detail on schedule but they were invested in completing the project on time and so long as we could see tangible progress each week we tried not to nag them too much. In the end the project was only slightly delayed in completion and it was definitely within acceptable tolerances.

Completing a deep retrofit is messy & expensive and there were plenty of times when we genuinely thought we would run out of money. Its not something to enter into lightly but it does totally transform your home, your quality of life in that home, it pays off in the long run, is better for the environment and is 100% worth it if you can afford it.

(Oh and if you are contemplating living in your house while they retrofit it. That would be a BAD idea. The dust, oh my, there is so much dust!)

Insulation

Insulation is the most important part of any energy improvement project.

A deep retrofit tries to find a whole house solution. The first step of this is to make sure the energy you use to heat your home stays in your home as long as possible.

One of the targets the SEAI had set for our grant was based on the number of times the air changes in our home. Too many air changes and your heat leaks out, too few and you will lack adequate ventilation and you risk stuffy feeling rooms and mould.

To reduce the air changes an airtight membrane was installed between the new underfloor insulation and the floor you walk on. The attic hatch was replaced by one with an airtight seal, we also removed the ceiling in our sunroom (a previously built extension). To complete what they call "the envelope" we also replaced the front door and windows.

Essentially you put heat into "the envelope" and you want it to stay there. The attic is outside the envelop so you don't heat it. As a result thick insulation between your attic and ceilings is essential.

Doors and Windows

Glass is a beautiful addition to any home but it is where you will lose a significant amount of heat from your home.

Glazing is also one of the most expensive elements of your retrofit. In the end we opted to invest in replacing all our windows with Triple Glazed windows at the expensive of completing some major cosmetic features of our home.

At one point we considered only replacing the north facing windows but we decided it would only create issues later to have windows of two ages in the house.

We highly recommend investing as much as you can in the quality of the envelope of your house. You can always decorate later.

Heating and Hot Water

Getting rid of our oil boiler was a huge priority for us as we want to cut down our reliance on fossil fuels.

We switched to an air to water heat pump. A heat pump works like a backwards fridge, it takes in air and removes the heat from it. This heats the water used to heat your hot water and radiators.

Unlike traditional heating systems that heat your house when it is cold. Heat pumps are designed to heat your house once and then keep it warm, for the best efficiency you want to get your home to temperature and then keep it there with only minor adjustments. As a result every radiator is connected directly to a super-insulated and quite large water tank and the radiators only ever feel warm (not hot) to the touch. We have hot water available 24/7 which is a great bonus.

Solar PV

The final step in improving the energy performance of our home was to get Solar PV installed. We choose solarhome.ie because they have years of experience of fitting thousands of systems and we felt that they really knew their stuff and they were fully invested in designing and fitting the best system for us, rather than a quick and easy off the shelf solution.

Our solar system consists of 16 solar panels with a max production of:

6.24kWp (16 x Bisol 390w Monocrystalline) of modules kitted to 5.7kWh battery storage
Santon Fire Safety Switch & Switch Gear
Alpha 5 kWp Inverter kitted to 11.4kWh storage capacity

Despite some pretty mixed weather since it was installed 4 days ago, our system has provided 71% of our power. I have included a chart in the pictures. We will update with lots more stats when the system has been running a bit longer. Our target is to produce 50% of the power we use for the year.

Note: We are not rewarded financially or otherwise for recommending House2Home or solarhome.ie. We just found both companies produced high quality work. If you are considering them and have any questions please feel free to reach out to us.