Overheating and our A2A
We are in yet another heatwave and there are lots of discussions going around about Retrofit and overheating.
Just to state that Retrofit does NOT cause Overheating, there are lots of factors that need to be considered but I hope we can all agree that the Overheating is due to our WARMING climate as a result of climate change not due to Retrofit.
To dispel some of the myths or just explain our own approach I will say that for the most part overheating has had a secondary position to keeping our homes warm in the Winter but now it has become apparent that these heatwaves are not simple just one offs but a significant sign of things to come and this may be the COOLEST summer we will experience.
Our house when we bought it just over 3 years ago, a standard 1950’s semi cavity construction, brick and blockwork with some retrofitted fluffy cavity insulation and very poorly performing aluminium frame glazing. The front ground floor living room was noticeably hot in the summer and absolutely freezing in the winter.
It had a very old and inefficient gas system boiler with radiatiors and we made the decision early on to cap of the gas and move to an all electric home.
It took us a while to obtain the necessary planning permissions for the work we were proposing including a large rear single story extension, reconfiguration of the general layout so for the first year or so we lived with no heating, minimal cooking facilities and rooms which were either exceptionally cold or boiling hot, even before this summer of heat waves we identified vulnerabilities in the house.
This lead us onto a decision about space heating and hot water and how we were going to navigate this and the options available.
Since we knew the works would be quite protracted but we wanted to be able to install a system suited for us we decided to uncouple our heating from our hot water.
The hot water system we installed was a Dimplex Edel, Heat pump HW cylinder- great with the solar and very cost efficient.
Space heating ( and Cooling)
The Heating /Cooling system we chose is a multi split Daikin 9KW Unit that can have up to 5 indoor wall units , each unit can run independently and as we have discovered is very efficient in both heating and cooling modes.
Also as we were gradually doing the house up it’s a much simpler system to retrofit using small bore copper pipe to carry refrigerant and a 22mm pipe for condensate.The syem has been installed in phases with the pipework being put in as we go through the house and then the unit can be installed once the room is ready.
Combining with Solar PV and battery is a dream, it costs very little to run if anything as the electricity generated by the solar more than covers the energy consumption of the unit. In fact so far in July we are in credit as far as energy consumption due to the combination of the PV with the battery- win win!
BUT;
I would always advocate education and passive measures in the first instance with overheating and indeed we have created our own brise soleil at the front of the house to keep the front room cooler ; see the photos below which showed that the front room with the curtains closed and the brise soleil kept the room at a comfortable 22 degrees C ( when outside was over 30 degrees C) but in our son’s room directly above it was a balmy 30 degrees C as we had not yet got round to putting his blind up!
We overheard a conversation last week where someone was talking about their top floor flat and that the living room was uninhabitable due to the heat, this was a modern new build construction, what happened to part O?
A really interesting podcast with Zoe De Grussa, well worth listening too here
https://zeroambitions.transistor.fm/129
So, yes absolutely consider passive measures, external shading, awnings, behavioural changes and consider how air flows through your home , optimising ventilation too.
Beauty is more than skin deep...
Or the house with ( Virtually) no heating
I deliberated between these two titles but I decided on the first one because it reflects more the my views of the renovation market and its relationship with retrofit
When homeowners are looking to do work on their home there is normally a trigger such as a new kitchen, a new bathroom, more space with an extension, a loft conversion.
Rarely does the homeowner say ” I want to retrofit my house” although I actually have had people say this to me and it really warms my heart, but it is not the majority.
Often homeowners are battling those niggly issues in their home such as cold rooms, damp and moul and that tends to come out in conversation. I visited a close friend the other day who has just moved into their new but not new home, a bunglalow built in the 1970’s that has the original aluminium windows and is frankly freezing. Despite their move from a period stone cottage with more holes in it than a grater this new home hasn’t lived up to their expectations of modern living despite the central heating.
But this is not uncommon, they are planning an extension renovation and loft conversion but my conversation with my friend was not about the aesthetic ( Which is important and more on that later) but the performance as well. The media is very good at portraying how your home should look aka Grand Designs, the to die for interiors all very lust worthy but we are pretty poor at promoting performance and comfort and glamour is a long way from retrofit.
But the two concepts are mutually compatible its just that some more thought and care needs to go in behind the scenes as upgrading the thermal performance is really all behind the scenes. My husband Ross’ attitude is that whatever he is constructing he wants to know that it is the best quality he can produce whether its hidden behind the plasterboard or on show for all to see.
Our own retrofit journey began 2 years ago when we slowly started to pull apart our rather tired looking 1950’s house and added a single story extension to it as well as upgrading all the rooms starting from the ground level and working our way up.
We are still working on it, thats partly because we have limited time to work on our own home and I quite liked not having a kitchen for a year (!) but also the time and thought that has gone on behind the scene, applying airtight liquid membrane to the blockwork walls, taping and sealing all the new windows and penetrations, linking the airtightness layer between the intermediate floors and the tricky loft space junctions. to name a few.Of course we could have just gone with a lick of paint, a few stud walls here and there but the house wouldn’t really have been improved- not underneath .
And now with all the work we have done we have not had our heating on this winter, we have a log burner for off cuts that goes on in the evening for a few hours but the next day the house is at a lovely steady 18-19 degrees- the downside is that I never know how cold it actually is outside!
Yes I love my new open plan kitchen living space, I love the front room that used to be so cold it was unbearable but what I love the most is the comfort the house provides, its like a lovely warm hug that you feel safe in, that’s what a home should be.
By the way for those interested we have 3 heat pumps, solar PV and a battery too to complement all the loveliness. A friend suggested that the collective noun for numerous heat pumps is a huddle!
Airtightness detailing in the ground floor kitchen extension with a lovely warm woodfiibre roof above the vaulted ceiling
The New Kitchen which was worth the wait
My message is that if you are thinking of any home renovations or upgrades try to think how you can also improve the performance of your home rather than just making it look pretty- it will future proof your home!
Old Home to New home Transformation
What if you live in a well loved home where your children grew up in , you spent many happy years in tat home but you started to resent it , it just wasn’t the warm cosy home you imagined growing old in anymore.
This is the situation that one couple from Oxford had; their home was not performing for them and as they grew older they really started to feel every little draught and gap. But they didnt really know where to start. Other things also played on their mind, such as the environment and climate change and their impact on carbon emissions as the house was so large it required two gas boilers coupled together to cope with the heat demand.
” I just don’t want to feel cold anymore and worry about the heating bills” , these were the words of our homeowner and its not an uncommon scenario.
This thought started them on their Retrofit journey, although they didnt quite know it as yet and they found a local community group , Low Carbo Oxford North that run some brilliant homeowner engagement sessions, called their housewarming Series to help homeowners in their situation; keen to learn and looking for answers.
This journey lead then to get in touch with Cosy Homes Oxfordshire, a one stop retrofit shop who we worked with on this project to undertake an extensive whole house retrofit to both upgrade and future proof their home.
The house, built in 1909 still had the original sash windows, these were all replaced with high performance contemporary casement triple glazed timber windows, the windows were repositioned into the planned external wall insulation using a clever Winframer structural insulation to mitigate thermal bridges and reduce the psi values associated with the installation of the windows tpo ensure they perform as well as possible and included airtightness detailing by taping the windows internally and externally using specialist tapes from SIGA .The External wall insulation specified by EWI Pro was 100mm Rockwool Duoslab with a thin coat silicon render system to reduce the wall U values to 0.3w/m2K and new loft insulation was added to 400mm alongside an airtight Welhofer Loft hatch.
FInally the ventilation system of the house was upgraded using Venti Decentralised CMEV units in the wet rooms and concealed trickle vents in the habitable rooms and to reduce the heat losses from the suspended floor a number of Airex smart airbricks were installed.
The homeowners took the brave step to make some radical changes to their home but they are now reaping the rewards, they have reduced their fuel consumption significantly but key to the project outcome is that they now appreciate their home is an oasis of comfort and are now looking at introducing renewables. They feel that their future is now more secure and their home is more energy resilient and no longer a burden that would be passed onto future generations.
A Bespoke Renewables Workshop
As part of our business ethos we do our best to keep our staff upskilled and are offered training opportunities where possible. When Will Gibbs ( Construction Skills Project lead) at Abingdon and Witney College offered to put together a bespoke Renewable workshop for us at Lambert Home Builds we jumped at the chance.
What better place to introduce our team to the ever evolving world of renewables than at the Next Zero Skills Hub in Abingdon, its a phenomenal training centre with more heat pumps then you can shake a stick at!
Our trainer was the incredibly knowledgeable David Matthews with a renewables and engineering background and took us through a full day including heat loss calculations, the inner workings of heat pumps ( I havent forgotten about Flow temperature!), MVHR, solar PV and rain water harvesting.
It was a fantastic day, so worthwhile and we just cant ignore the changing landscape of renewables within the construction industry and having this resource on our doorstep was invaluable to upskilling the team .
With huge thanks to all the team at Abingdon and Witney College for giving us their time, I can highly recommend this course to any contractors out there, do reach out to them Im sure they would love to hear from you. Next stop domestic ventilation….
