Jointly hosted by Low Carbon Oxford North and Low Carbon West Oxford on 19 May, our final ‘Spring Workshop’ from Communities for Zero Carbon Oxford looked at ‘Improving your home to use less energy’.
We were delighted to be joined by a wonderful group of expert contributors as well as ‘real people’ who had carried out extensive retrofits to their homes:
- Brenda Boardman (Oxford University’s ECI, LCON trustee, and Woman’s Hour ‘2020 Power List for Our Planet’ Innovator)
- Saskya Huggins (Low Carbon Hub)
- Gary Irvine, former Home Energy Assessor
- home owners Damian Ryan and Will Schreiber
You can access a recording of the event and slides on Low Carbon West Oxford’s website, along with links to the slides and videos of the other events in the series.
Here are some of the headline message from the event:
- If you live in Oxford, 29% of city’s carbon footprint comes from domestic buildings.
- Start with understanding your property and options.
- Energy Performance Certificate (EPCs) for houses are important both in terms of Government targets and regulation, and to provide a starting point for decisions in your home – Government aspiration is for all homes to achieve ‘C’ rating. If you haven’t got an EPC, get one done!
- To reduce energy use in the home, think about behaviour, appliances, and the fabric of your home.
- Start with the easy stuff – it can make a big difference (loft insulation being the big one).
Below we have summarised presentations from the speakers and listed a range of links and resources with useful further information. You can also access a list of Q&A from the event here.
Disclaimer: The information below has been compiled from various contributions to the event. Low Carbon Oxford North, Low Carbon West Oxford and other contributors are not in a position to accept liability for any loss or problems arising from use of any information or resources in this report or linked sites.
Improving your home to use less energy – key messages from the speakers
Introduction – Brenda Boardman, LCON
How should you think about decision making and energy in your home?
Some key stats:
- 20% of all UK CO2 comes from our homes
- About half from gas and half from electricity
Energy Performance Certificate (EPCs) for houses are important both in terms of Government targets and regulation, and to provide a starting point for decisions in your home:
- EPCs in the UK cover space and water heating and fixed lights, ie they are mainly about gas
- Current average is D
- There are statutory targets and policies aiming for a minimum C rating for fuel poor and rented property, and a government aspiration that ‘as many homes as possible should be EPC Band C by 2035 where practical, cost-effective and affordable’ (Clean Growth Strategy 2017).
How this will be achieved is unclear and there is lots of current debate e.g.
- Should minimum ratings be mandatory, and should they be linked to property sales.
- Should this be done through regulation rather than grants. We may need to accept that many of us will have to pay for this eg using green finance.
The key message is: start with your EPC and if you haven’t got one, get one done!
Context – Saskya Huggins, Low Carbon Hub
Some key stats:
If you live in Oxford, 29% of city’s carbon footprint comes from domestic buildings.
Average energy use in the home:
- Space heating 64.7% (generally gas)
- Water heating 14.5% (generally gas)
- Lighting and appliances 13.8%
- Cooking 5.4%
The energy hierarchy – how should you prioritise action?
1) Energy Conservation (use less energy): e.g. turn thermostat down, use heating control; draw curtains as heating comes on; chimney balloons; maintenance e.g. dust fridge freezer coils.
2) Energy efficiency: e.g. draught excluding.
3) Renewable Energy.
Centre for Sustainable Energy: a huge range of guidance and advice on home retrofit, e.g. central heating controls, cavity wall insulation, electricity usage of different appliances, and lots more.
Low Carbon West Oxford ACT Now resources: guides and information sheets on a range of topics including home energy.
Overview – Gary Irvine, Home Energy Assessor
1) Understand your property and your requirements
- Structure and state of property and services – Any reports – Survey from purchase? EPC? Whole House Plan?
- Current energy use – analyse bills, meter readings etc.
- Any legal constraints? Listed Building? Conservation area? Lease? Planning consent?
- How you need/wish to live in it? E.g. number of people, time spent in it, mobility or health issues
- Resource issues i.e. time, effort, disruption tolerance and money.
2) Understand potential options
- Reduce energy requirements – behavioural ie how you use the property and/ or simple changes eg using heating controls, thermal curtains, draught proofing
- Improving insulation – roof, walls, windows, floor, doors (e.g. draught proofing windows, doors, skirting boards etc can be quick win).
- Improving existing heating system – adding better controls eg TRVs (Thermostatic Radiator Valves)
- Replacing heating system – gas to electric? Heat Pumps etc (electric is much more expensive but with heat pumps you’re starting to get to similar kind of cost level).
- Generating your own energy – PV, solar heat
- Prioritise desired actions
- Understand inter-dependencies of actions
- Establish availability of materials and suppliers
- Draw up plan with timeline and costs
- Plan may well have stages, say stage one is replacing roof, each of which are treated as separate projects and then allow time to assess their impact before moving onto next stage.
- Enter into agreement with suppliers and/or contractors (buy materials if DIY)
- Do the work
- Analyse how it went and the impact of the work
- Feedback lessons learnt and any changes into the next stages of the plan
Improving insulation – options
In order of effectiveness:
- Roof – heat rises and so it makes sense to prioritise roof. Lofts can be easily and cheaply insulated using rockwool or sheep wool. More complex if you have a room built into roof. Consider accessing from outside or using insulation backed plasterboard internally.
- Walls – cavity walls usually can be fiilled. Solid walls are harder to deal with (lots of these in Oxford). External is easier and less disruptive if feasible. Internal has downside of losing internal space and is very disruptive. Detailing around openings and at top and bottom is important.
- Windows – refurbish existing? Secondary glazing if cannot replace (on cost or heritage grounds) Double glazing. Consider amount of glazing – as even triple glazing performs much worse than a cavity wall.
- Floor – relatively cheap and easy for suspended timber floors (remember ventilation). Solid floors more expensive and very disruptive (but could be linked work if switching to underfloor heating).
- Doors – draught proof old doors. Can get modern high performance doors (but they don’t save much energy).
Home owner case study (1) – Damian Ryan
Duke Street, Victorian ‘two-up/ two-down’ Victorian end-of-terrace:
- Solid brick walls
- Suspended wooden floors and concrete slab
- Mains gas heating (<10 years old condensing boiler)
- Double glazing throughout
- Lots of halogen spotlights
- Minimal loft insulation (and poorly maintained)
- Kitchen extension with poly-carbonate roof and walls
- EPC rating E
Main works carried out
Easy and inexpensive:
- Loft insulation (increased to 300mm)
- Thermal curtains, reflective sheeting behind radiators, thermostatic valves on radiators, LED spotlights, plugged draught spots, dealt with rising damp
- New kitchen roof – insulation upgrade to current regs
- Loft conversion – insulation upgrade to current regs plus additional party wall insulation; new boiler; new internal walls downstairs (for fire regs) = better heat management
- External wall insulation – max green deal grant (£7.5k) covered 2/3 cost. Back and side of building.
Other less obvious measures:
- Painted flat roof white with elastomeric paint to help with summer cooling (£100-150)
- Installed low voltage heat recovery fan in bathroom (£250)
- Installed underfloor polystyrene insulation on ground floor (£200)
- Blocked off and insulated fireplaces
Impact: warmer and drier in winter, cooler in summer; same or less in bills for larger house, more occupants and renewable energy tariff; EPC rating from E to C.
Motivations (in order): nicer (more comfortable) home; add value to property; reduce bills; cut emissions => climate factors are important, but it’s important that these are aligned to what matters most to people
- Start with the easy stuff – it can make a big difference (loft insulation being the big one)
- ALWAYS use any building work as opportunity to improve energy efficiency
- Go beyond reg requirements whenever you can with insulation
- Keep an eye out for govt grants (pretty sure they’ll be back in not-too- distant future)
Next steps to further improve energy performance more challenging
- Gas boiler ultimately needs to be replaced with electric air-source heat pump but how practical and affordable is this?
- Front of property should ideally have EWI too, but that impacts on street character => planning permission issues ? neighbour reaction? sale value?
- So, bumping up against more challenging / expensive problems to move beyond EPC ‘C’ rating
Question is whether that’s a problem – and if so, how to motivate further ambition from householders?
Home owner case study (2) – Will Schreiber
Main works carried out
- External wall insulation – used Green Homes Grant
- Air source heat pump (Mitsubishi) – using Renewable Heat Incentive (RHI)
- Double and triple glazed windows
- Loft room
- Wood composite front door
Cheap/ quick measures
- Draught exclusion
- A+++ appliances
- Thermal curtains
- Efficient water things
- Smart LED (some sensors)
- Radiator additives
Key messages and experiences
- Quite sceptical of EPCs: for example, previously got from E to D just by doing LED bulbs. Have to take some recommended measures with pinch of salt
- Price does not equal quality (or a ‘responsible’ supplier), and there is high variability- Some quotes were inexplicably high and proposed to be a less effective spec or lower quality equipment.
- Lots of whizzy things that sound exciting, cost a fair bit, and deliver far less than simple behaviour change (e.g. smart thermostats, energy use indicators), which may be needed anyway!
- Be honest with how you actually use your home.
- Don’t plan to insulate in the winter – or change your heating system.
- Suitability assessment follows agreement to proceed; pretty unknown what can happen before you agree to proceed.
- Avoid groups with dedicated sales people – indication of ‘cowboy’ operations, it will probably work but also potentially some dodgy arrangements in place.
- Some savings will not appear overnight.
Rose Hill support – Eleanor Watts, RHILC
No-interest loan are available for residents of Rose Hill and Iffley who use Cosy Homes Oxfordshire for energy efficiency measures. For info, email firstname.lastname@example.org.
Improving your home to use less energy – Resources
- Videos of previous events from Communities for Zero Carbon Oxford (tree care, waste, and food)
- Centre for Sustainable Energy: a huge range of guidance and advice on home retrofit, e.g. central heating controls, cavity wall insulation, electricity usage of different appliances, and lots more. Here’s a link to its energy advice resources.
- Low Carbon West Oxford ACT Now resources: guides and information sheets on a range of topics including home energy.
- Cosy Homes Oxfordshire’s youtube channel, which includes a range of videos covering retrofit measures from solid wall insulation to Ground Source Heat Pumps, as well as a number of case studies.
- Cosy Homes resources: Cosy Homes Oxfordshire is a ‘paid for’ service but has a free home planner (‘Plan Builder’, available here) that you can use to better understand the solutions that might be suitable for your home. They also have some video resources explaining whole house retrofit and topics such as insulation and heat pumps.
- Haynes Manuals/ Eco-House and Home Insulation
- Oxford City Council have a good summary of grants and support available to pay for home improvements on their website. The council pages includes support that is available for tenants and also advice on tariff switching, which although doesn’t reduce your energy use, can save you significant money.
- Passivhaus case study: Laurie Michaelis carried out a Passivhaus retrofit on his home in Oxford. It is the second in the UK certified to EnerPHit Plus standard, which means the PV produces as much energy year-round as the house would use in standard occupancy. Here is a link to its entry on the Passivhaus Institute website. A case study and webinar can be found on the Green Building Store website.