Home Energy Assessments Q&A

Conducted by MCFly volunteer Philip James, March 2012

Kit Knowles, Ecospheric

Q: What do your home energy assessments involve? How are they different from standard Energy Performance Certificate (EPC) assessments?
KK: Ecospheric are offering to provide 40 households with energy fitness and retrofit reports. This consists of a survey utilising thermographic and moisture mapping techniques to pinpoint heat loss within a property and produces a report with prioritised recommendations for individual properties. The bespoke report not only contains information about the property surveyed but also a comprehensive range of advice on sustainable living ranging from efficiency measures to occupancy health and behaviour.

Energy Performance Certificates applies a standardised approach to energy saving advice. This is only applicable as a piece-meal approach. We tend to take a fully holistic approach. For instance our show home was rated a band G and was only able to achieve a band E according to my EPC. We are currently just short of an A band!

Q: What kinds of measures are recommended, are they very different for different house types?
KK: Our strategy starts off with myth busting, during a lifestyle interview. This highlights the flaws in many common approaches to energy efficiency in the home. It discusses items to be careful of when creating a product/system specification. It additionally covers the effect of humidity in the home and fleshes out the importance of ventilation.

Some examples:
• Chimneys are the number one point of heat loss. The continual draw caused by these devices primarily drive the cold air infiltration (draughts) felt elsewhere in the property, windows, doors, air bricks and floors. Additionally blocking these up is a sensitive business and is the most common spot in which damp is found. We have developed cheap and effective methods of sealing chimneys to ensure a damp free (low humidity) solution preventing both conductive and convective losses. Additionally we are able to integrate Wood burning stoves (DEFRA smoke control exempt) utilising direct air feeds. This provides external air direct to the combustion chamber ensuring there is no interference caused to the internal environment exacerbating heat loss.
• Whenever glazing solutions are being specified it is important to focus on airtightness not just the number of panes of glass. The framing and space bar technologies account for 80% of heat loss through a typical double glazed domestic window. Particularly warm edge spacer bar technology costs very little (typically £18 more per pane) and reduces conductive losses through that element by a whopping 900 times. We also advise against PVC framing due to longevity and performance. As the product is thermoset by nature there is no scope to modify or upgrade. As such we often find that 100 year old timber frames can be brought up to a higher standard than a so called high performance PVC window. This is because I can
add layers of airtightness technologies and change out the glazing in a timber frame utilising micro routing techniques, a method not applicable for PVC. Finally PVC plastic is a high-density produce with poor thermal conductivities and contains hollow vented sections that allow convective turbulence to remove heat from the interior and transfer to the exterior. If specifying new framing technology there is no way composite timber frames can be beaten. These frames have two pieces of softwood (low density and sustainable) separated by a rigid insulation as a thermal break. They incorporate multiple layers of gaskets and focus on airtightness.
• MVHR (Mechanical Ventilation with Heat Recovery) – [you must] considered the following contradictive dilemma:
o You need to seal up all the gaps in your house to ensure to don’t waste energy.
You could reduce up to 50% of your heating bill through this approach. However to ensure the health of your environment please knock some 6 inch holes in your walls to ventilate!!
o In a winter setting when it is -5°C outside and 20°C degrees internally, your chimneys and other extracts draw the heated air outside creating a localised negative pressure. As air has been removed it must therefore be replaced by physical law. So the air bricks, windows/doors and floors allow the -5°C external air to infiltrate. This results in a 25°C differential that requires the radiators to work pretty damn hard. MVHR is the only solution to this issue. This extracts the 20°C unhealthy moisture laden air from kitchens bathrooms and toilets and carries the air stream to a heat exchanger. This box recovers 92-95% of the heat energy and transfers this into an incoming -5°C fresh air stream, which now 16-18°C, gets delivered into all the living spaces throughout the property (Living rooms, bedrooms etc.). It also minimises pathogen levels in the dwelling through humidistat control, removes all particulate matter including pollen (for all those hay fever suffers out there), reduces dust and dust mite levels considerably and even capable of providing cooling potential during the summer.

Our approach is a primarily convection emphasised (air tightness/draught proofing), conduction is our second thought (insulation). Ensuring high standards of building and occupancy health is placed as a top priority. It is often compromised in traditional approaches. Often non breathable oil-based products bound with carcinogenics like formaldehyde http://www.cancer.gov/cancertopics/
are utilised.

Q: How important is occupant behaviour in your assessments and in achieving energy use reductions? Do you have any methods for ‘educating’ occupants?
KK: Occupant behaviour controls every aspect of a refurbishment which is why we start off every project with a lifestyle interview. The classic statistic is lifestyle effects alone could reduce house-hold energy consumption by 30%.

Q: Do all the recommend measures have a short payback period?
KK: We prioritise our recommendations using the following factors:
• ROI (Return On Investment)
• Lifestyle affects, it must suit the house hold lifestyle. Many items commonly remain under-utilised or disliked if incorrectly specified
• Future proofing ability (detaching the occupants’ dependency on contracts and energy providers, particularly in a pension setting)
• Property format, some properties lend themselves to particular approaches/technologies (or vice versa).

Q: How could the measures be paid for? Do these assessments make you confident about the Green Deal?
KK: Well the Green Deal is one method of raising capital for such a project but my main reservations are the following:
• A well-established phenomenon known as the ‘Rebound Effect’ could catch many people out. This is when energy saving technologies are installed and after which the bills increase as lifestyle changes often absorb any benefits through a comfort improvement. As the reduction expected on energy bills due to the energy saving installations is pegged to cover the loan repayments as part of the green deal, the rebound effect would leave people with a large short fall (previous energy bills +new loan repayments + increased energy bills). What I am saying here is that energy education is a critical factor.

• Additionally one of the main drivers for people to undertake eco refurb is to see the bills tumble which would not be the case with the Green Deal. A psychological effect only, but powerful one none the less.
The accreditation required of both the installers and specifiers is more of a monetary payment, not any true training. This lack of technical competence will see the installed energy saving systems come up short on expected savings.
It is being touted as free money for energy efficient measures but in realistically it is only a loan, one set to benefit the big six energy companies more than anyone (although financing is open to anyone). Not particularly geared towards SME’s as hoped.
We like to use the following tips to help home owners make these changes more affordable:
o Take a holistic approach, techniques like thermographics can list in priority order what needs doing. This means the first pounds spent will be the first pounds to pay for themselves.
o Any time any maintenance needs doing on the property specify the replacement/solution to be energy saving and durable. i.e. flat roof leaks, replace with a new slightly sloped structure (for durability) and fully insulate the void when the roof comes off. The new pitch also proves space for extra insulation.
o Integrate as many jobs together as possible to simplify any contracts and benefit from prep/clean up. Often two separate jobs become significantly cheaper when done as a single project.
We guide the home owner through the entire process ensuring the prices hold fast and the specification is not compromised. Builders are well-known for swapping out materials specified for ones which they have deals for with their suppliers, with little concern of the outcome for the construction detail.
Q: What levels of uptake of recommended measures do you expect? What’s next after this phase of the project is complete?
KK: We have had a great uptake, with many home owners already engaging with our company on major refurbs.

Charlie Baker, URBED and Jonathan Atkinson, Carbon Coop

Q: What do your home energy surveys involve? How are they different from standard EPC assessments?
CB: They use full SAP not the reduced data version used for EPC’s. There is also a personal user interview to try and shape the standardisation of SAP into something more directly useful to the occupant. The SAP tool is built by us so we can use it as a design tool rather than an opaque box that spits out results. This allows a more optimised set of proposal to be arrived at, that will both most cost effective and bill/CO2 reduction effective in use.

Q: What kinds of measures are recommended, are they very different for different house types?
CB: Not sure yet we’re still doing the processing, but yes they are survey specific.

JA: Measures will include solid wall insulation, new windows, doors etc, new A-rated appliances, biomass boilers, wood burning stoves, roof felting, solar PV, solar hot water etc etc! Whole house retrofit essentially. Interestingly we’re also considering commissioning a range of new technologies and gadgets from local suppliers and inventors to deliver energy savings bespoke to particular properties – this forms part of our mission to stimulate local economic development and job creation. It’s also worth saying that a number of the homes visited need ventilation systems and strategies and those will form part of our recommended measures packages.

Q: How important is occupant behaviour in your assessments and in achieving energy use reductions? Do you have any methods for ‘educating’ occupants?
CB: Occupancy is crucial as it tells us what the deviation from the assumed use in SAP is so that we don’t suggest measures that are hopelessly unaffordable for that user. Education while obviously started here is for later, it’s an assessment after all.

JA: The measures recommended are a balance between the measures appropriate to the building and the measures appropriate to the householder (i.e. how much heating/energy they use, health issues, behavioural patterns etc). ‘Education’ is a broad term but it’s worth noting that these assessments need to be seen in the wider context of the Carbon Co-op member offer. Accessing an assessment is part of a member benefit, members adopting measures are also encouraged to share experience, tips and advice, open their homes to friends and neighbours and share learning.
Members can also access best practice advice and case studies. So it’s about peer support and co-learning rather than ‘education’ per say. Just to note the work we’re doing as part of LEAF has allowed us to develop the these member benefits and we’ll be launching membership officially from April 2012, in other words this is what we plan to do rather than what we are doing at the moment.

Q: Do all the recommend measures have a short payback period?
CB: No.

JA: But the report will recommend a series of packages that can be installed over time and shows how much carbon can be saved at what cost per each package. Some to do now, others to do later.

Q: How could the measures be paid for?
CB: the measures, should they be deployed would be paid for out of a finance model devised by Urbed for the community green deal project we did in the midlands (www.shap.uk.com/projects).
This involves a combination of long term finance planning, low interest rates by using community finance, cross subsidy from Feed in Tariff and possibly the Renewable Heat Incentive (we’re still investigating this).

JA: The finance model referred to by Charlie has been used to inform the Carbon Re-Investment Society, this is the Carbon Co-op’s social finance arm and is constituted as a community benefit society. We aim to be able to issue low cost loans to householders in the near future.

Q: Do these assessments make you confident about the Green Deal?
CB: No, not as currently proposed, but the principle is sound, it’s the proposed deployment that has some issues. The assessment is likely to be too simplistic. the restrictions on access to ECO [subsidy] are silly – all walls for 2050 target are hard to treat. The restriction on finance methods exacerbate the early funding gap, the proposed cost just the icing on the incredibility cake. The lack of long-term view as to how we meet the rest of the reduction target after green deal has taken all the bill headroom for relatively low hanging fruit is alarming.

JA: As Charlie says, we are really supportive of Green Deal but feel there are gaps and need for improvement in a number of areas. To add to Charlie’s concerns, there is an assumption that community-led organisations such as Carbon Co-op will create demand for the Green Deal and deliver household assessments, however, there’s a real lack of clarity around how that might be resourced and funded.

Q: What levels of uptake of recommended measures do you expect?
CB: No idea, we using this project primarily to hone an assessment method, secondly to enhance our knowledge of different archetypes.

JA: We’ve had great feedback from the householders and around 1/3 of them have already indicated they will seriously consider adopting some of the packages recommended. Obviously we won’t know for sure until the reports are delivered and we discuss next steps but we’re hoping that figure will rise.

Q: What’s next after this phase of the project is complete?
CB: Write it up, perfect the assessment method, hopefully get it on-line. Ideally take a few retrofits forward to help inform the green deal debate.

JA: We’ll encourage these householders to sign up as Carbon Co-op members and for as many as possible to progress through the retrofit measures. For those that do we can offer project management of works, source appropriate local suppliers, if possible at discount (discount will only come from bulk demand), and assess finance options. As well as all the other member benefits listed previously around sharing information and peer learning.

Q: Anything else you’d like to say?
JA: The LEAF funding has been extremely useful in allowing us to develop the Carbon Co-op survey method and the survey will be at the heart of our member offer as of April. I think there’s concern that LEAF funding throughout the UK has led to a proliferation of survey methods and techniques which may confuse and bewilder the householder. As part of the Greater Manchester Retrofit board we’re working to develop consistency and standards across the city region and through Greater Manchester feedback to DECC.


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