Hitting the Wall (Insulation)!

It’s been an intense few months for everyone in the UK (and now globally too…), and a lot has changed for me personally too. I’ve made a decision about “LittleEcoTerrace”, and I’m going to do my best to “finish the job” and see if we can make Superhome status. We already moved the house from a D to an A (CO2 via EPC) for ~10% of its value, but I know there are lots of things we can still do that might just be enough to push our CO2 saving to the 60 % required to get Superhome status.

A bit over a month ago, I passed my final exam (viva) on to become a Dr. of Chemistry, for which I focused on atmospheric chemistry motivated by Climate Change and Air-quality. A personal hero of mine is an American lady called Katherine Heyhoe (and she even liked one my of tweets once… *swoon*), who recently publicised a study showing climate scientists’ credibility is affected by their actions (insideclimatenews article). I strongly believe this, but I think it is more poignant that if even those who can start to understand the sheer scale of impacts climate is having don’t act… then who does?

There are some obvious things that we should be doing for our LittleEcoTerrace project, but we won’t as they should have been done earlier in the project if they were going to be done at all. One of these is extending our insulated floor through our 70s kitchen/bathroom extension, another is installing full mechanical heat recovery (MHR). There are some little ideas that might happen in the future too, like putting a light well in at the top of the stairs… But below are my loose plans for work on the house over the next bit. I am very open to any  suggestions or comments!

Phase 5 – Doing the bathroom

This is the most simple and standard bit of work I want to do. Our bathroom needs some love and most people end up doing this at some point. In our place it has been workable, but not great, since we moved in. We spruced it up a bit with some paint and added the active ventilation (see “Its draught to let hot air escape“). However the whole extension remains hard to heat due to large heats sinks of the floor and ceiling (which I want to tackle in Phase 7). As well as generic aesthetics, I will insulate the (metal) bath.

bathroom on arrival… a few things have changed, but not much…

Currently the bath touches two external walls and un-insulated tile floor. It keeps its heat for a mere few minutes. So i intend to move it slightly away from the walls and put some insulation in the gap and around the bath. I want to replace the metal legs with plastic ones to insulate from the floor too. It’s been an aim ever since we arrived to one day have a proper hot bath!

Phase 6 – Insulating the two internal walls

Two of the large heat sinks are the two solid external walls of the old terrace. The simple and cheapest option would be to do external insulation, but we are rather fond of the traditional Victorian brickwork. Therefore we are looking at internal insulation, and one that doesn’t take that much space from the room. The one that we are often recommended is called SpaceTherm. It is a aerogel, like the insulation used by NASA on the Space Station, it is high performing and takes up little space but is quite expensive.


Phase 7 – Insulating the extension

The extension is a massive heat sink in the winter and overheats in the summer. It is very common and most extensions and badly thought out conservatories you see around will suffer from this. To sort this I’m looking into insulating the walls and ceiling. The floor also needs doing (currently just tile on scree), but I can’t do this without ripping out the kitchen that was put in only shortly before we arrived.

The simplest option would have been to put insulation atop of the flat roof, but as we have solar panels there (see blog post “To PV or not to PV“) it would be troublesome. I’m still looking into this and open to ideas. However, currently the winning idea is to attach kingspan inside to the ceiling of the extension. To make this happen I will have to be convinced that we won’t end up with/can avoid condensation.

I also am keen to have a go at doing external insulation, but as we already have the cavity wall insulated this would have less impact. making sure the (flat) roof covers the extra depth of wall might also pose some challenges.

The story before?

Just for completeness and to put the new work in context… here is a brief history of the work we’ve done so far ( inc. previous renovation and “eco-renovation” ). To summarise the changes to the original house to date i’ve clumped together the broad “phases”. Technically some of these overlap, or the timings are mixed between phases, but for the sake of this blog article I will pretend that I had more of plan…

Phase 0 – From the beginning… 

Many years after the original (~1899-1902) construction of the 2-up-2-down terrace, a 70s extension with was added to the back. This had no insulation. The house also went through a typical modernisation with electricity and central heating.

Phase 1 – Recent updates to house (up to ~5 years before we moved in)

A bit had been done to the house in recent years. Double glazed  windows ( not very good PVC )… and I am disappointed by this, especially as the house had a beautiful wooden and stained glass door about ~1 year prior to moving in… However costs limit the ability to replace these and this highlights the need to do things right first time with the large expenses. A new (modern, but non-condensing) boiler was fitted, which unfortunately died within 5 years. And a recently installed IKEA Kitchen. This is the point it was at when we moved in.

Phase 2 – Floor 

We dug up the whole downstairs floor to deal with a damp problem and added lots of insulation and a new solid wood floor at the same time. (described on blog post “Floored by insulation”).

Phase 3 – Ventilation/Insulation boost

The house was very leaky and poorly insulated. We boosted the insulation in the walls, roof, ceiling hatches, and installed bathroom active extractor at the same time as insulating up all vents (as described in blog post: “Its Draught to let Hot Air“)

Phase 4 – Added solar panels (PV)

We are very fond of these. They produce ~3.3MWh a year (record so far: 3.53 MWh), which approximately equals the gas from our 1st year in the house and the electricity from the year before we moved in (total: ~3.3 MWh). Nowadays we consume a very variable amount of electricity and gas,  depending many people are in house/usage/etc but generally it is a lot lower as we are using energy off the panels. (described on blog post: “To PV or not to PV“)

Solar panels on the main roof

Phase 5 – Yard (Not yet complete!)

An underplayed part of sustainability is lifestyle change. It’s not that sexy, unlike fancy tech solutions but it can make a very large difference to a carbon footprint. We are most of the way through redoing the back yard to make it easy to be a base for cycling. So far this has been re-making the shed into a seat, building a bike shelter, and finally we aim to lay the Victorian quarry tiles we took up from inside the house (upcycle!).


I am not sure whether we will be able to make it to the 60 % Co2 saving requisite for being a Superhome with these savings. My approach to everything so far has been piecemeal and been a big learning journey. I am very keen to reduce the footprint and learn how to do a few things along the way. Whatever happens LittleEcoTerrace is definitely, in a plodding way,  moving towards being an “Aspiring Superhome”.



York Green Open Homes – Living in a “Eco” home

We’re part of York Green open homes this weekend! If you are about York, come see what “eco” measures people have done! These include from a “Passivhaus” under-construcion (more about passivhaus), 1960s council house, a 1930s semi, detached, bungalow, and many more. Green Open Homes is a national project and they have a even have a nice video intro of the project.

Frankly, flattered doesn’t quite cut it to explain how we feel about being asked to do Open Eco Homes. Our project is a lot smaller budget than a lot of projects you hear about. For the event, we’ll be showing how we reached our goal to take a thoroughly normal terrace home in York from a “D” to “A” grade (EPC) eco home for less that 10% of the value. We’ll show how we achieved that and also made our house a net exporter of electricity with low bills. There’s another aim we always had but didn’t mention often; we wanted to make sure it was still a “normal” home. One that we can live in comfortably, and be eco without having to drastically change anything about our lifestyle.


As the hosts (@StNicksFields) say: “Find out how to turn your house into a comfortable and efficient home from people who have done it!”

Us: We’re Not Hippies, Honest

Both of us have long been interested in the environment and technology that reduces our impact. That’s based on our concern about climate change. But being a scientist and an engineer, we’ve often noticed that we’re much more interested in the cold evidence than the sentimental stuff. You’re more likely to find us obsessing over doing our recycling correctly than getting upset about pandas.


This means we sometimes choose different paths to an eco lifestyle. A good example is being vegetarian – we’re not. A lot of our friends in the eco world are; some for ethical reasons, some for environmental impact. We like eating meat now and then so we’d find giving it up unenjoyable; instead we eat meat infrequently, and eat less of the most environmentally detrimental meats. Using the information we have, we can reduce our impact without having to change our underlying habits and lifestyle.


So this means we need an eco home where:
  1. we’re happy every change made had a rational, evidence-based argument to support it.
  2. little day-to-day input or behaviour change is needed from us.

Most of our blog topics have been info-heavy and focused on the numbers. This one catches us in a thoughtful mood as our Eco Open Homes weekend approaches and we start talking about what we’ll tell our visitors about what it feels like to live in a home like this.

Our “Eco” Home


The goal of this project was to convert the cheapest house we could get in York to a “A” grade (EPC) eco home for less that 10% of the value. We essentially achieved this. Due to cosmetic choices and additional non eco measures (like our FSC oak floor + relaying backyard with our reclaimed victorian tiles) it may end up being closer to 15%.


The project has involved some big changes such as installing solar power panels, insulating the floor and dealing with damp problems, and some smaller changes of insulating and draft proofing the house and installing a chimney pillow.


What’s it like to use electricity in an eco home?

Well, in 2014 we produced 3.4 MWh and in 2013 we used 2.6 MWh. So overall, we’re producing 130% of what we need. On the face of it, we’re golden. If we assume out consumption is constant and you look into it a bit further, it’s more likely that a portion of that 2.6 MWh came from the grid when it wasn’t sunny. So we sold spare units at sunny times, and bought National Grid units at others.

So we’re happy with the total amount of power we use. We do the sensible little things; we switch off stuff at the socket when we’re not using it. We hang clothes on a line instead of having a tumble dryer. But we keep an appliance others might identify as wasteful; a dishwasher. We just like it too much. Our routine is to wash up by hand, but when we have guests or have a big elaborate meal and then feel lazy, we love having that dishwasher. Over the year it looks like it’s OK really, so although we discussed ditching it we decided it wasn’t necessary.

Full array - extension and main roof
Full array – extension and main roof
The main change we made when the PVs were installed was not what we did but when we did it. It’s better for the environment if energy used in our house comes straight from the PVs, directly displacing a CO2-heavy unit of grid electricity. If we use power at night, we’re taking an eco hit twice; once because we’re getting grid electricity at a higher emissions content, and twice because we’ve sent our sunshine power to others via the grid at a noteworthy transmission loss; ~8 % doesn’t make it to the other end. That’s rubbish.
So, the washing machine and the dishwasher go on in the daytime. High energy stuff like the kettle and the shower are going to consume more than the panels punch out whenever you do them, but daytime is better, and when a wash isn’t on is better still.


There’s more we could do; we have an average kettle and an average shower and they use a lot of power. The shower is 8.5 kW. And we are both too addicted to long hot showers to ever get a shower timer. But we’re honest with ourselves that we enjoy these luxuries and we want to keep them.

What’s important to us is we never, ever have to say “you can’t turn that on”. We just get on with life as normal. You quickly forget why laundry-time is about 11am when the sun will be high and it’s just habit. We use our laptops a lot and have a constant tea-making operation going on. When we break 20 kWh in a day it makes us smile, but if it’s a rubbish

We like that any set of people could move into this house, and without changing a single bit of behaviour, they’d have a massively decreased electricity footprint.
With the recent developments in home storage batteries, Tesla PowerWall being the most widely-promoted, it could soon be even easier. 10 kWh storage provides 10 x long hot showers, maybe 60 x boiling the kettle. 2.6 MWh a year averages to 7.1 kWh a day. So this battery would instantly take our house off-grid for a long stretch of the year, since it could provide a day to two day’s power even if PV output is very low. Based on our 2014 generation data, we think we’d have around 200 consecutive days entirely grid-free; we’ll be able to calculate this better once the new Open Energy Monitor is installed. We’d only need to take from the grid in the depths of winter.


Is an eco home cold?
No, ours is pretty cosy. Because it’s insulated so well, the sunshine and the people tend to warm it up ok. We keep our gas boiler off completely between mid-March and mid-October. It doesn’t cause a problem. We have two little low-power electric heaters, 400 W each, which we specially bought to suit the PVs. If it’s a cold but sunny day, first port of call is to switch these heaters on to top things up. We’ll pick a room or two we’ll mostly be in for the day and just heat that area. When it’s a small house anyway this isn’t particularly difficult to accommodate.
If it’s both cold and overcast, we make use of the boiler. Because we both work full-time, it’s on a fairly restricted timer, and then controlled with a thermostat. We have a wireless one you can take with you. We carry it about so the temperature is set right for where we are.


Since our old boiler packed up and we got a new one, we’ve had new thermostatic flow taps on the radiators. They haven’t been very useful though, since if you change it and then move rooms you have to alter the taps set up again. We don’t really see the point, and we don’t really use them, they’re just all set the same.
New Boiler!
New Boiler!
It’s worth saying, our preference is for a moderate temperature in the house. We dislike having a home heated really hot, and we have both cultivated exquisite jumper collections we love to wear.


Sometimes our guests want the place hotter than we’d set it up. We will happily turn the boiler on outside of normal months for their comfort, and since the new boiler’s been in, it’s easiest to just hand them the wireless thermostat and say “set whatever you like”. It doesn’t make a big difference to the overall picture, it’s our day-to-day habits that influence it more.
What are the bills like?
Basically energy bills don’t exist for us anymore. We use about £25/month of grid electricity, and about £10/month gas which is heavily in the winter and obvisouly pro rata’d.


FITs and export tariff payments are made quarterly. Obviously they vary depending on generation. But it’s always significantly more than the energy bills.
So overall our house doesn’t cost us money to run, it looks after us.


Dealing with the rubbish


In the house, we recycle as much as possible. Our council pick up recycling for paper, card, plastic containers & caps, glass, and tins. There’s no food waste collection, but we compost our raw food waste/teabags for the community garden down the road. We collect up more unusual recyclables over time and take them to the main centre now and then; tetra pack containers, small electrical items, batteries, bits of metal, bits of wood. Old furniture goes to the community furniture warehouse or up on Freecycle. Old clothes go to the charity shop or the cloth bank if they’re really knackered. We’re in the habit of making use of packaging again in the house where we can.


By recycling everything possible, you become aware of it when you’re buying things and try to avoid them or only buy the minimum you need. So examples of stuff that’s a pain to dispose of responsibly  are paint/highly volatile chemical items, things that are not possible to disassemble like metal items moulded into plastic, food with tons of packaging particularly if it’s got foams, and cheap electronic items that won’t last long. Sometimes you have to buy them but it’s good to avoid just accumulating unnecessary stuff.


What goes in the general waste bin is mainly cooked food waste, plastic films, plastic-coated foils (like crisp packets) and expanded foam packaging. Actually food packaging and food miles/seasonality would be the next big thing to act on to continue getting our carbon footprint down.


Was it worth it?


We started this as we were fed up with what is described as affordable housing being completely not so (about us page). The money costs were largely as expected, the time costs were pretty high. It meant months of living in a not-finished home, of organising every detail of the bought-in work, and painting or sanding or sawing every night as soon as we got in from work. Occasionally we got really frustrated by it. But we’ve met our energy and cost goals, whilst making the house a cosier, cheaper and more sustainable place to live. We also got the chance to make a comfortable home that’s just right for us, and we’ve found it’s far easier here than in any rental places we’ve lived to follow an eco lifestyle even when you’re really busy. We think this place is set up so that anyone who lived here would be more eco even if they didn’t really think about those issues. We’ve always believed that living in an eco house should improve your quality of life too, and we feel like this house does that for us.


Yes, it was worth it!