York Open Eco Homes

Eco = ecological + economical

Our York Open Eco Homes project showcases homes that have undergone energy efficient home upgrades. This makes them more comfortable, cheaper to run and reduces carbon emissions.

We do this by coordinating "open door" and related events in conjunction with York Community Energy. During these sessions you can meet and visit the homes of York residents who have carried out Eco-Retrofits. Learn from fellow York residents and share your own experiences!

Below you'll find case studies of homes that have been part of past events. Please note, some case studies include links to products and companies: inclusion here does not constitute St Nicks endorsement.

Other events have included:

  • Eco Homes Café focussed on heat pumps
  • An online course on retrofitting in partnership with Maria Moise of Retrofit Plus Architecture
  • Visits to Climate Innovation District by Citu in Leeds, the City of York Council Eco Depot
  • Talks and workshops at St Nicks

Please keep an eye on our events pages for future Eco Homes events. If you would like to showcase your home at the next York Open Eco Homes please contact us.

Case Study: 1990s Bungalow with edible garden

Audrey & Duncan have done all they can to make their bungalow energy efficient since moving in in 2014. Below is an overview of what they had done up to 2016 in their own words.

Photovoltaic panels South facing 3.9 KWp system. We can show you 18 months of weekly and monthly performance figures plus five years performance from our previous house. A mobile energy monitor shows live readings and this enables us to maximise the solar power by switching on appliances when the sun is at its brightest. We received over £650 from the Feed in Tariff last year.

 Electricity use We record electricity usage and this shows how PV panels reduce the amount we buy. We buy 100% renewable electricity from Ecotricity.

 Lighting We have fitted low energy light fittings including LED. We make the best use of daylight.

 Electrical Appliances All are “A” rated. A plug in energy monitor shows the power consumption of each item.

 Boiler We have a modern high performance condensing combi boiler located in the loft. Graphs of gas usage available. Gas is bought from Ecotricity.

Conservatory We open the door to the conservatory during the spring and autumn to allow the heat from the solar gain into the rest of the bungalow. We are able to sit in the conservatory from March to October without extra heat.

 Windows All modern double glazed PVC with 20mm air gap and patio door window has an argon filled gap.

 Water We collect enough roof water for all our garden demand. We minimise our mains water use by collecting the initial cold water from the hot tap to use for rinsing etc.

Recycling We keep waste to a minimum and full reuse and recycling undertaken by using charity shops, St Nicks, Freecycle, Preloved and Gumtree.

Garden Waste We have two compost bins in use taking all garden and kitchen waste.

Garden Plants Small garden is entirely dedicated to edible plants including vegetables, herbs & fruit trees. A greenhouse allows most annual plants to be grown from seed which are often saved from previous years and distributed wider through seed and plant swaps. In 2016 we grew 100 different plants. The garden is fully organic.

Transport We use buses whenever possible so as to reduce our carbon footprint. Our car usage is under 2000 miles per year.

Case Study: Little Eco Terrace

The young owner couple wanted to see if they could turn the cheapest house in central York into an “A” rated eco home (as per Energy Performance Certificate) for less than 10% of its value. They have succeeded by employing a number of eco-refurbishment measures from low cost draught-proofing to some major building works and installation of solar PV panels. They have documented the process on their blog which is well worth checking out, and have a lot of monitoring data from their self-installed system.

Since the first York Open Eco Homes event, Tomas has helped St Nicks organise a series of related events including an Eco Homes Show & Tell which focused on low cost energy saving items. He and his fiancee have also started eco-refurbishing a flat in London which they are documenting on their blog.

Case Study: 100+ year old semi

The home owners wanted to reduce their carbon footprint and have a warm house and hot water, despite the house being over 100 years old, with solid brick walls. They have installed a number of eco features and are very happy to talk about their experiences gained over a number of years (not everything went according to plan!). Adrian has written up this guide to the house which he gives to visitors.


This house was built over 100 years ago, about 1912, and is probably one of the earliest semi-detached houses in York. It was built by Wray the Builder, who also ran a brickyard further up Huntington Road – using local clay to make bricks to build houses like this one. After this pair of semis, Wray built the large house next door, 147 and later 155 and 157. There are also ‘Wray’s Cottages’ near Birch Park and many other houses built of Wray’s bricks. We moved to York in 1992, and chose this house for the chance to live beside the River Foss, close to central York. Our garden looks across to ‘Wray’s Island’ in the River Foss.

Solar Hot Water Panels

This was our first foray into ecological improvements, in 1996. We were already interested in Permaculture (its ethics are Earth Care, People Care and Fair Shares), Organic Gardening, a Vegetarian diet, cycling around York, and other greenish lifestyle ideas, but at that time we didn’t realise just how serious a problem man-made global warming and adverse climate change would become. We liked the idea of hot water from current sunshine instead of using the ancient sunshine locked up in fossil fuels like coal, oil and gas. At the time, we felt we had given way to pressure sales techniques, but – 19 years on – the 8 Sunuser solar panels on our south facing roof have worked impeccably and probably paid for themselves three times over, or more, without any government subsidies. From about April to October, they have provided almost all our hot water, with just an occasional top up from the electric immersion heater or gas central heating if e.g. we need an extra bath, unexpectedly. Even in winter, the daylight, rather than bright sunshine, takes the chill off the water and raises its temperature to about 15C, which saves fossil fuel in bringing it up to whatever temperature we need. You can’t see the panels from the ground, but you can spot them on the aerial photo of the Yearsley Bridge area; and you can see the meter and controls in the airing cupboard, near the bathroom upstairs.

Draught-proofing and insulation

With national campaigns, and for self-preservation, we did various low-key draught strips and loft insulation etc. but the big problem with an older house like this is the fact that there is no cavity in the wall, so there is nowhere to pack insulation into it. There are ways of insulating walls by adding an extra internal layer, but we have never felt we could cope with the disruption that would involve. We did look at external wall-insulation too, to try to improve our Energy Performance assessment and get our Energy Performance Certificate up to the D level that qualifies for higher levels of government subsidy for e.g. Solar Photo-Voltaic panels (SPVs) for generating electricity from sunshine. But it was very expensive, even with the government’s Green Deal funding, where they give you a financial incentive and you pay the rest through your electricity bill over many years, to make it affordable. And then, overnight, the Government cancelled the Green Deal! So we tried to pursue other things instead. 


We were lucky that the main windows, especially on the coldest east-facing wall were already double glazed when we moved in. Over time we double-glazed the windows that were still single glazed in the kitchen and at the back of the house, and felt a great improvement in comfort, even if we couldn’t put a figure on any savings we might have made on heating bills. In 2014, we were surprised to be offered replacement windows, to higher modern standards than our old original ones through a national/CYC window scrappage scheme. This wasn’t free but I did qualify for a subsidised rate, because I am of pension age. So we did get new ‘high spec’ windows at the front, and later one window at the back.

Renewable electricity

We used to have fossil fuel electricity from one of the ‘big six’. When electricity from renewables began to be available it was a bit more expensive but we switched to Ecotricity anyway. Now they guarantee to charge no more than your local big six supplier would. They have also published a Vision for 80% renewable UK electricity by 2030.

Gas Central heating

When we moved in, the house was set up with an electric cooker, gas central heating, and hot water with an old, but very reliable, Glowworm boiler. We tried several times to get Solar Photo-Voltaic panels installed, especially when the government brought in a high Feed-in Tariff (FiT) which made it very appealing financially, as well as environmentally. But the problem was getting our non-cavity wall house to be energy efficient enough to qualify for the highest level of FiT. We put in more roof insulation (some of it free from our electricity company); moved to low energy light bulbs every time a bulb needed changing (and we should probably move on to LED lighting next); and we considered replacing our gas boiler for something more efficient, but even with thermostatic valves on every central heating radiator and a central thermostat and all the things that help get a good EPC (Energy Performance Certificate) we couldn’t be sure of getting it high enough. So we kept the old gas boiler and looked for other improvements first.


We tend not to replace things until they wear out, trying to use the embedded energy in each item as long as possible, and postponing the replacement cost! But bit by bit we have got an A+ rated washing machine, fridge and freezer, and we didn’t replace the existing dishwasher when it broke down.

Saving water

We have a Hippo in our upstairs cistern to cut down the excess volume of each flush. Another way is just to fill a small water bottle and sink that in the cistern. We recently had to install a new loo downstairs and it has a variable flush (two-button) cistern instead. We have also started collecting rainwater in a water butt from the bay window roof to use in the garden and can extend that idea. Some people reuse their ‘grey water’ e.g. from the bath for gardening, too, but we haven’t got to that yet!

Solar Photovoltaic Panels, Voltage Optimiser and a Biomass (Wood pellet) boiler

In 2014, our old gas boiler finally died and there were no replacement parts any more. Rather than replace it with a new gas boiler we explored renewables: Ground Source Heat Pumps (not enough ground we could use) and an Air Source Heat Pump (wrong sort of central heating – they are better for blown air than radiators). We got a range of quotes from local suppliers but they seemed quite expensive, even with the Government’s Renewable Heat Incentive (RHI). In the end we went for a combination of Solar Photovoltaic Panels on our east and west facing roofs (not as good as south facing, but that was already bagged by the Solar Hot Water panels!) It means they start generating soon after dawn and carry on till tea time, when the trees begin to get in the way. We also got a Voltage Optimiser, a gadget on the grid side of the electric meter, that reduces the voltage used from that supplied (in our case by Ecotricity) to what is needed, and can save up to about 10% of the electricity bill. We also went for a biomass boiler – not logs or wood chip, which are cheaper to obtain but need even more space to store, but wood pellets, made from compressed sawdust. They are very dense and so take up less storage space (but still quite a lot) and burn with a high efficiency. These are all very new so we are still getting used to all the controls and the best way to set them and it is too early to quantify the costs and benefits we will actually make in either carbon footprint or finances. Sadly, we can’t recommend the installers we went with, who landed us with long delays and some other problems. That is probably part of being an early adopter and despite those problems we are pleased with the technology and hope in time they will be as rewarding as our Solar Hot Water Panels have been. It’s quite a complicated area and probably easier to explain by talking to you about any particular bits you want to know more about. And before you go ahead get all the technical and financial advice you can, and only work with trusted, and preferably local, suppliers with a proven track record!

Chimney sheep

Although it’s not very green, we have kept the open fireplace in our sitting room for family and seasonal celebrations and the nostalgic memories of a log fire. But when it’s not in use, we now have a Lakeland wool Chimney Sheep. This is a 100% Herdwick wool pad that goes up the chimney to act as a draught excluder, and is simple enough to put in – and take out whenever you want to have a fire.

Case Study: DIY upgrade of a 1920s semi

For Lyle and Natalie, who took part in our 2021 York Open Eco Homes, reducing their carbon footprint has been the primary motivation for retrofitting their house. They’re very happy to enjoy other associated benefits though, such as a healthier home and financial savings. They’ve done most of the work themselves:

Prior to moving into the home, we installed insulation in the floor, walls and loft. In our selection of insulation, we looked for a low thermal conductivity, high recycled content and low VOCs (volatile organic compounds).

We used multi-layer foil insulation in the walls, as this type of insulation takes up the least amount of space with the lowest thermal conductivity value. On the exterior walls, we installed timber battens horizontally on the old walls, stapled the insulation to the battens, then vertical counter battens were fixed through the insulation to the horizontal battens, and finally new plasterboard was fixed to the vertical battens.

For the lounge, after removing lots of debris from under the floor, we installed a vapour barrier on the ground and rigid foil face polystyrene insulation around the foundation wall. We used a different type of multi-layer foil insulation as the first layer at joist level, we then added rock mineral fibre batts on top of the foil insulation. In the kitchen, approximately 80% of the slab had to be removed. Then to prevent rising damp, we added a vapour barrier, rigid foil face polystyrene insulation, and repoured the slab. As a final touch for comfort, we added an electric heated flooring system.

In the loft, we removed the old fiberglass insulation since it had become wet, dusty and less effective over time due to settling. We cleaned the loft using a hepa-filtered hoover prior to installing the new insulation. We installed a layer of rock mineral fibre insulation between the joists, and then a second layer of the same insulation across the joists creating a finished depth of approximately 400 mm. In the loft where the soffit of the roof meets the ceiling, we installed 50mm rigid insulation, which maintains adequate roof ventilation while reducing the thermal bridging in that area.

To ensure adequate ventilation throughout the home and regulate humidity, we have first fixed a mechanical ventilation heat recovery unit. The unit can be up to 80% efficient at recovering heat, while exchanging the air in the house with filtered air from outside.

We insulated the heating and water pipes with a high-grade lagging to reduce heat loss during supply. The heat and water pipes along with the main water supply (originally lead) were upgraded to plastic. We opted for a gas hot-water boiler and an unvented stainless steel 203L tank installed in a purpose-built boiler room placed in the back garden. This combination will ensure an ample hot water storage for heating and water supply with the added value of future proofing the systems. Our goal is to move to a heat pump within 5-10 years, but maintaining a gas supply line also allows for the possibility of one day using Hydrogen. We sourced antique cast radiators mostly to suit the period of the property. However, the larger cast radiators should also function better with a heat pump system due to the larger surface area and lower continuous flow rates.

To further reduce our energy demand, we changed the gas hob to an induction hob. Any new (or slightly used) appliances purchased for the home have an energy efficiency rating of A+ or higher. In addition to making our home more energy efficient, we opted for more sustainable purchases in the finishes as well.

Fortunately, the flooring had been removed from the house prior to our purchase. While a popular choice, we did not want carpet in our home due to our issues with asthma and past problems with indoor allergens. Our house now has a mix of linoleum and cork flooring. Both types of flooring consist of natural renewable materials, maintain a healthy indoor environment, and range from carbon neutral to carbon negative. We used clay-based paints with very low (essentially zero) VOCs. We debated oak or bamboo for our kitchen worktops. Oak has the benefit of being local and from certified sources, but Bamboo as a fast-growing grass still seemed to be the more ethical option.

In our purchasing, we try to buy used as much as possible, but if we need to buy something new, we buy products with recycled content and/or made from renewable materials. We also used Facebook marketplace and free cycle to ‘recycle’ anything removed from the home. For example, some of the old kitchen cupboards are now in the Farming Museum’s volunteer kitchen. Once we have completed our home retrofit, we plan to nature-scape the front and back garden by replacing the gravel and concrete with native pollinators.

Case Study: Victorian energy efficient retrofit

You can watch George talk about his home project in this video and/or read the description below.

George Robinson’s aim was to undertake a home upgrade (retrofit) that would have minimal visual impact on the house while achieving substantial improvements in comfort and energy savings. Partly thanks to local contractors and partly George himself, this standard Victorian terraced house is transforming into a modern, comfortable home that doesn’t cost the Earth to run.

By modelling the house in PassivHaus software, local architect Phil Bixby helped evaluate the relative impacts that different fabric adjustments were estimated to have and George’s work was then focused on four key areas:

  1. Insulation
    We used a combination of woodfibre insulation (100mm on the walls and between floor joists), 100mm cork (for the kitchen where there was a greater risk of moisture) and upcycled 100mm plastic insulation in some places such as the pre-existing dormer bedroom. All floor insulation was done DIY while all internal wall insulation was done by a great local plasterer / insulator Craig Young.

An important decision was whether the original chimney stacks should or should not be removed. In the end we decided, aided by the PassivHaus calculations, that removing them internally (but retaining the external stacks at the top of the house so as not to change the external look of the property) was the way to go. This allowed for larger areas of insulation to be installed more quickly, removed one of the key areas for heat loss (air up the chimney!) and meant overall we actually gained internal space despite having installed 100mm of insulation on all internal walls that were in direct contact with the outside.

To reduce waste, the original fireplace was reclaimed by a local fireplace restorer and all waste timber was taken by Leeds Wood Recycling.

  1. Air tightness
    Reducing heat loss of a home requires high levels of air tightness as well as insulation, which basically means making sure that heat doesn’t leak through draughts and faults in fabric. George had a test done by Northern Air Tightness Testing Services before the start of any works, which showed a rather leaky 12 air changes per hour. The higher the rate, the more energy is required to keep a house heated so George’s aim is 3-5 air changes – he’s already succeeded in halving the rate to 6. (For reference, the super efficient Passivhaus standard is up to 0.6, for which active ventilation is essential.)

A lot of attention was paid to improving air tightness throughout the house with DIY measures. All ground floor floors were membraned,  foil taping was used behind all skirting boards and around all points of exit from the property that could be boxed out (e.g. foul pipes). Mastic sealant was used for more visible areas such as electricity mains supply from the street to the fuse box.

The test also revealed kitchen bifold doors and dormer room windows had poor air tightness despite being double glazed. These were replaced with FSC certified timber framed windows and bifold.

  1. Ventilation
    Once we got rid of uncontrolled ventilation which leaks heat 24/7, we needed to ensure good fresh air supply. As part of the work we had radial ducting taken to every single room in the house with all air supply ducts insulated, allowing for more efficient central cooling should that be needed on in the future (let’s hope not!). These have been hooked up to a mechanical ventilation unit with heat recovery (MVHR). It’s a pretty amazing piece of kit that uses about the same electricity as a fridge (30W) but on winter days saves the property having to expend approximately 600W of heating cold air which otherwise would have come in if we had not undertaken the air tightness measures. It also manages air moisture as well as filters our air. The system, ducting runs and installation was undertaken by ADM Systems.
  2. Heating system and wider energy

We have had an 8kW air source heat pump installed to supply space heating needs and domestic hot water for the winter and shoulder months. During the summer our hot water is primarily met through solar heating (Navitron evacuated tubes). Additionally we installed PV panels and a Tesla battery – on sunny days we are totally off grid with some left over for the next day! The energy equipment and system was installed by T4 Sustainability with general plumbing carried out by Andy Fisher.

We have installed a home designed and built energy monitoring system (using a Raspberry Pi) that uses inexpensive sensors and pulse meters to monitor overall system performance across the heat pump, solar thermal, PV and battery. The aim is to show the extent to which we can demonstrate both the impact of the fabric adjustments on overall heating requirements but also the relative efficiency of this more modern equipment.

There is still lots to do but George estimates that heating demand will be 1/3 of what it previously was, and the heating system is free in the summer and hopefully 250% efficient in winter.


Case Study: Fishergate Terraced House

Mike Childs has written up his thoughts and experiences below.

The climate emergency isn’t new. If you read climate science report to the 1992 Earth Summit, it was already clear by that data that our climate was in trouble (and nature). Given that perspective I’m a bit ashamed that it’s taken us the best part of 20 years to get as far as we have on house. But that said, life and particularly finances can get in the way of making rapid progress (which is why the government needs to do much more to help householders make their houses green).

But enough of the politics, this is what we’ve practically done at our terraced house (37 Frances Street in Fishergate).

In 2004, after we’d bought the house after renting it for a year, we fitted loft insulation. We choose to use sheep’s wool because we liked the idea of it. It also has a quick payback.

In 2006, after we’d saved-up enough, we replaced all doors and windows with wooden high-spec energy-efficient replacements. We went to the Green Building Store in Huddersfield for these. We choose wooden because we wanted products that would last a lifetime if well maintained. We worked out (wrongly) that it would take something like 20 years to get the payback in terms of reduced energy bills but in fact it will take over 100 years. We would have installed them anyway because it made a massive difference to the comfort of the house.

In 2010 we fitted solar PV panels to provide us with electricity. Again we had to save up for these, although thanks to a grant and the generous Feed-in Tariff payments (paid quarterly by the government depending on how much electricity is generated) we are now making a profit on these and will do for another 15 years. Most new systems will have 20-year payback. Over the early years our system provided for all our electricity use, although obviously we produced surplus in the summer and need to buy electricity in the winter. We now have a heat-pump, so our electricity use has gone up, so we are now a ‘net importer’ of electricity.

From around 2010 as we redecorated rooms we fitted ‘insulating wallpaper’. We used a product called Sempatap, which is basically a 1cm think foam which you stick to the inside of an exterior wall and then cover with lining paper. We decided to take this approach rather than the traditional internal wall insulation because with very small rooms we would lose a lot less space. It isn’t the optimal solution, but it makes a noticeable difference (and has eliminated mould problems as well).

Last year (2019), we bought an air-source heat pump. This was another expensive investment. It cost us £13,000, which included fitting a new hot water tank and the remedial work needed in the bathroom as a result – we needed to rip out an existing cupboard to replace it with the airing cupboard. Over the next seven years we will get back something like £4,000 from the Government’s Renewable Heat Incentive. Heat pumps capture heat from the air outside and use it to heat your home, and cleverly they even do this when it’s freezing cold outside (see more info on Friends of the Earth website).

Stupidly we haven’t tracked our energy bills through the years to monitor what difference the different items have made, although since we’ve changed how we use the house a lot over the same period I’m not sure it would be very instructive if we had (we’ve got kids now, and also work at home more).

We’ve also not done everything yet. We haven’t fitted under-floor insulation to our front room and hall (I’d love to get hold of the Q-bot) and external wall insulation would be great (but would probably need to be a whole street approach to be practical).

Everything we’ve done has made a difference but the windows and doors plus heat pump have probably made the biggest difference to our carbon footprint. We also keep the thermostat low (18 degrees), which will make a big difference.

Greening our house is a big part of trying to lessen our environmental footprint. Not owning a car is also makes a big difference (we do rent a car for some holidays, and occasionally borrow a friend’s, so we’re not angels). We don’t eat meat at home and have cut down on dairy a lot, although I treat myself on our rare excursions to country pubs.

But the reality is that we’ve been able to afford to go green, albeit over a long period. If we are really going to address the climate emergency the government needs to pay for this work upfront.


Case Study: Eco-refurbished Victorian end terrace

Local Passivhaus architect Phil Bixby has supported us and taken part in Open Eco Homes events with his lovely house refurbished to a high energy efficiency standard. It’s well worth reading more about it on his website or watching the short video below.