Frequently Asked Questions
Welcome to our FAQs. Here, you’ll find clear answers to common questions about EPCs, floor plans, legionella risk assessments, heat loss calculations, and our mentoring services for energy assessors.
This page is designed to help homeowners, landlords, agents, and fellow assessors quickly find clear answers and understand each service.
Search for a specific question above, or browse by category below.
Frequently Asked Questions
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- EPC FAQs
- Floor Plans FAQs
- General FAQs
- Landlords & Letting Agents
- Legionella Risk Assessment FAQs
- Mentoring FAQs
A typical EPC assessment takes 45–90 minutes, depending on property size and complexity. The assessor inspects all rooms, heating systems, insulation, and energy-using features to produce an accurate rating.
All our floor plans meet estate agent and property marketing standards. They are professionally measured, accurate, and delivered in clear digital format suitable for listings or EPC submissions.
Yes, heat pumps, solar PV, solar thermal, and battery storage are all recorded in your EPC assessment. Under RdSAP 10 they’re modelled in more detail, but your rating is based on calculated running costs, not carbon savings, so the actual impact varies by system.
- Heat pumps can improve your rating if they replace a less efficient heating system.
- Solar PV is modelled on system size, orientation, and overshading, and is likely to help your rating.
- Battery storage is recorded but currently has little effect on the score.
- Solar thermal can help by offsetting hot water demand.
Planning to install renewables? It’s worth checking with a qualified assessor first on how the improvement is likely to show up in your rating.
Landlords, building owners, and businesses with water systems that could support bacterial growth need legionella risk assessments, including showers, taps, and hot water tanks in residential or commercial properties. This is a legal duty under the Health and Safety at Work Act 1974 and the COSHH Regulations, not just good practice. We carry out assessments for domestic and light commercial properties (up to around 9 taps); larger commercial systems, cooling towers, and evaporative condensers fall outside our scope, so get in touch to check if we can help. Read more: A Landlord’s Guide to ACOP L8 Compliance.
Costs vary depending on property size, type, and location. Bluewire Hub offers competitive rates, which include a full assessment and a certificate for legal compliance.
Duration depends on individual goals. Some clients benefit from a few focused sessions, while others require ongoing support over several months.
Homeowners and landlords are legally required to have a valid Energy Performance Certificate (EPC) before marketing a property for sale or let. It gives buyers and tenants clear information about the property’s energy efficiency and expected running costs.
Tenants don’t need to obtain an EPC themselves, but they’re entitled to a copy from their landlord. Marketing a property without a valid EPC can lead to financial penalties.
Not sure if your property needs one, or how to get one? Get in touch.
The assessor spends 45 to 90 minutes at your property, depending on size and complexity. They’ll measure windows and doors, calculate floor area and heat loss, check party walls, and access the roof space to assess your home’s fabric and insulation.
Heating, ventilation, hot water, and any renewables are examined too, along with fuel types and controls like thermostats. Under RdSAP 10 the data collection is more thorough than before. It’s non-invasive, no drilling or moving furniture, but the assessor needs access to every room, the loft, boiler, and meters. If insulation or another feature can’t be physically evidenced, it may not make it into the report, so have any documentation ready.
You don’t need to be present, but being available to answer questions helps. Read more about preparing for your visit.
The assessment examines your water system for legionella hazards, including water temperatures, storage tanks, and dead legs (infrequently used pipework), and identifies any high-risk areas. You’ll receive a written report explaining what was found and the control measures needed to keep the system compliant.
Common challenges include misunderstanding DEA conventions, such as recording room types, heating systems, or insulation details, and arriving on site without adequate preparation. Mentoring helps you adopt a structured approach: planning ahead, understanding the property layout, and following a consistent routine for each assessment. This ensures your use of DEA equipment is effective and that your assessments are accurate, safe, and professional. See preparation tips in our YouTube preparation guide.
Yes. We can turn hand-drawn sketches or older plans into polished, digital formats suitable for marketing or compliance. This ensures your property meets estate agent requirements.
The assessor needs to walk through the whole property, every room, the loft, boiler, hot water system, and meters, to collect the data required under RdSAP 10.
It’s non-invasive: no drilling, lifting floorboards, or opening up the boiler casing. They won’t carry out any work, but do need clear access to inspect walls, measure windows, check heating controls, and evidence any insulation that’s visible. If access to the loft hatch or boiler cupboard is blocked, they may have to make assumptions or arrange a second visit. Paperwork for solar PV, window installation dates, or cavity wall insulation is helpful if you have it.
Visits typically take 45 to 90 minutes. Read more about getting ready for your EPC.
The launch was delayed from October 2026 to the second half of 2027. The government confirmed this delay in March 2026, and the exact date is still to be published.
Yes. We provide structured mentoring to help new assessors develop the skills, confidence, and knowledge needed to complete assessments accurately and efficiently.
Under the current proposals, no. Fossil fuel heating systems, including efficient condensing gas boilers, are capped at band D on the Heating System metric regardless of age or efficiency.
Ofgem’s July 2026 price cap update reflected higher wholesale gas costs, pushing gas unit rates up by around 24%, compared with roughly a 5% rise in electricity unit rates.
Not always, and not always safely. For some older or solid wall properties, wall insulation carries a real risk of cold bridging, damp and mould. A proper assessment looks at what’s appropriate for the specific building, not just what raises the score on paper.
Lighting is now assessed bulb by bulb rather than by fitting. Assessors count and classify every bulb in the property, LED, CFL, or incandescent, rather than estimating from fitting types.
This lets the EPC model reflect actual lighting energy use more accurately: the more low-energy bulbs you have relative to the total, the better your lighting score. Properties with a lot of halogen or incandescent bulbs may see a slightly lower score than under the old methodology.
The change reflects how widely LEDs have been adopted in UK homes, while still accounting for any inefficient bulbs that remain, giving a more realistic picture of a property’s actual energy use.
Not necessarily. As proposed, properties need band C on Fabric Performance plus band C on either the Heating System metric or the Smart Readiness metric, not both, so solar PV and smart controls could be an alternative route.
Yes. Bluewire Hub provides tailored support for your DEA portfolio as part of our mentoring programme. With extensive experience as a trainer and portfolio marker, and holding the Level 3 Certificate in Assessing Vocational Achievement (CAVA), we guide you in compiling, structuring, and presenting your portfolio to meet accreditation requirements.
Whether you are a new trainee or preparing for accreditation, our portfolio support ensures your work is organised and presented to the highest professional standard.
Government has confirmed a single compliance date of 1st October 2030 for all private rented homes in England and Wales to meet a new minimum standard equivalent to EPC Band C.
Because the efficiency gain rarely justifies the cost. Your assessment records window details in full, width, height, orientation, frame material, glazing type, age, and gap, but this is mainly used to calculate heat loss rather than to recommend replacement.
Replacing windows delivers a relatively small SAP score improvement for the money, so measures like better insulation, a heating system upgrade, or improved heating controls usually appear higher on the recommendations list instead.
No. Our mentoring also supports experienced assessors looking to improve efficiency, expand services, or enhance business operations.
Yes. The RdSAP 10 software generates improvement recommendations automatically from the data collected during your assessment, things like better insulation, a newer boiler, or renewables such as solar panels or a heat pump.
To be included, a recommendation must improve your SAP score by at least one point, and suggestions are ranked by cost-effectiveness. They’re standardised guidance based on the data gathered, not a full survey, so practical factors like planning restrictions or available space aren’t accounted for.
Mentoring includes practical guidance, review of assessments, business advice, and one-to-one support. It focuses on real-world challenges to build competence and confidence.
Local authorities will be able to issue fines of up to ÂŁ30,000 per property per breach once the new standard takes effect. The current minimum standard, EPC Band E, carries a maximum fine of ÂŁ5,000 per property.
Floor plans include room dimensions, window and door placement, layout of living spaces, and sometimes furniture suggestions. They are essential for sales, lettings, and planning purposes.
We provide services across Milton Keynes and surrounding towns including Bletchley, Wolverton, Silverstone, Brackley, Towcester, and Daventry. If you’re unsure whether we cover your area, please contact us for confirmation.
A full assessment should be reviewed every two years, or whenever the water system or building usage changes, in line with HSE ACOP L8 guidance. Regular monitoring ensures compliance and reduces risk. Read more: How Often Do You Need a Legionella Risk Assessment?.
An Energy Performance Certificate (EPC) assesses a property’s energy efficiency and environmental impact, rating it from A (most efficient) to G (least efficient). EPCs provide guidance on energy-saving improvements and are required by law when a property is sold or rented.
No. The price cap sets the maximum unit rate and standing charge a supplier can charge on a standard variable tariff; your actual bill still depends on how much energy your home uses.
A better EPC rating means the modelled cost of heating and lighting the home is lower, which generally does translate into lower bills. But the rating is based on standardised assumptions about occupancy and heating patterns, not how a specific household actually lives, so it’s an indicator of a property’s efficiency rather than a guarantee of what any individual’s bill will be.
For most homes, topping up loft insulation and improving heating controls tend to offer the quickest, lowest cost improvement in rating and running costs, though the right first step depends on the property’s construction.
Dead legs are sections of pipework or outlets that are rarely or never used, such as an old shower head or an unused tap. Water sitting stagnant in these sections warms to room temperature and provides ideal conditions for legionella bacteria to grow, so they’re a key focus of any risk assessment. Removing or regularly flushing dead legs is one of the most effective ways to control legionella risk. Read more: Water Temperature and Dead Legs.
Worth considering, yes. Your original EPC stays valid for 10 years, but it only reflects the property’s condition at the time of assessment. Upgrades made afterwards, new insulation, a replacement boiler, solar panels, or structural changes like an extension or loft conversion, won’t show up in your current rating.
An updated EPC captures the improvement, which helps with marketability, compliance with upcoming legislation, and eligibility for grants. For landlords this matters if the changes bring the property closer to the proposed Band C requirement for new tenancies.
Looking for advice on improving your rating? Read our guide here.
Preparation is key — research the property beforehand and understand its likely features. Develop a routine: start outside, then move methodically through each room, recording measurements, heating, lighting, windows, and insulation. Keep your essential DEA equipment organised, follow safety practices, and adapt your approach to the property. Mentoring helps turn these habits into second nature, giving you confidence and efficiency from your very first assessments. Find out more on our DEA Mentoring page and watch our workflow videos.
Look for an assessor who’s fully accredited and trained in the current RdSAP 10 procedures. You can check accreditation on the government’s EPC register.
A local assessor with a strong reputation and experience across different property types is often a good bet, construction, heating systems, and renewables all vary, and familiarity with these helps an assessor capture your home’s energy performance accurately.
Before booking, ask how long they’ve been accredited, whether they know local building styles, and whether they can offer clear pricing and timelines upfront.
How long does an EPC last?
An Energy Performance Certificate is valid for 10 years from the date of issue. There is no legal requirement to renew it within that time, unless you are selling or letting the property again—at which point a valid certificate must be in place.
However, we recommend updating your EPC if you’ve made significant energy improvements. This might include installing a new boiler, upgrading insulation, adding solar panels, or fitting an air source heat pump. A new EPC will reflect these changes and may result in a higher energy rating.
An up-to-date certificate not only helps when marketing a property but may also support compliance with future regulations or eligibility for funding schemes. Increasingly, we’re seeing mortgage lenders take EPC ratings into account, with properties that achieve higher ratings often qualifying for lower interest rates.
An EPC remains legally valid for 10 years, but if your home has since had work done, or your bills feel out of step with the rating, it is worth having it reviewed rather than relying on an outdated snapshot.
Yes. All our digital floor plans are compatible with major property portals, ensuring seamless integration for online listings and marketing.
Pricing is based on the number of taps in the property, not whether it’s classed as domestic or commercial, so a small shop and an equivalent-sized home are quoted the same. Our quote form has four tiers: up to 3 taps, 4-6 taps, 7-9 taps, and 9+ taps; get in touch for an exact quote for your property. Read more: DIY vs Professional Legionella Risk Assessments.
Yes. We can add room labels, annotations, and key features to highlight a property’s best points, making it visually appealing to potential buyers or tenants.
In most cases, yes. Uninsulated floors, especially older suspended timber ones, can account for a surprising amount of heat loss. Insulating helps retain heat, reduces how much you need to heat your home, and makes floors noticeably warmer underfoot.
It also helps prevent cold bridging, and can support a better EPC rating, which matters for future saleability, letting, and upcoming regulations. For homeowners looking at energy-saving improvements, it’s often a practical, cost-effective place to start.
We assess domestic and light commercial water systems, such as houses, flats, and small shops or offices with straightforward hot and cold water supplies. We don’t cover cooling towers, evaporative condensers, or complex commercial systems typically found in hotels, care homes, hospitals, or large multi-let buildings; if your property falls into one of these categories, get in touch and we can point you toward a specialist.
DEA mentoring provides practical guidance and support for both workflow and confidence. Mentors teach a structured routine — from preparation using resources like Rightmove and the Valuation Office Agency (watch my YouTube guide here), to systematically working through each room recording measurements, heating, windows, and insulation. Mentoring accelerates learning, allowing DEAs to adopt best practices and work confidently from their very first assessments. Learn more on our DEA Mentoring page.
It can, especially with suspended timber floors. These rely on airflow underneath, usually through air bricks or vents, to prevent damp and protect the floor timbers. When insulation is added, that ventilation needs to be maintained, not blocked.
Solid floors don’t need underfloor ventilation since there’s no void beneath them, though general room ventilation still matters for air quality.
A professional installer will maintain or improve airflow as required by building regulations, so insulation and healthy ventilation work together rather than against each other.
HSE guidance (ACOP L8) allows a landlord to assess a straightforward domestic system themselves if they’re competent to do so, but most people lack the specific water-hygiene knowledge to assess risk correctly or produce compliant documentation. A professional assessment ensures the report meets HSE expectations, reduces your liability, and gives you evidence of compliance if it’s ever needed. Read more: DIY vs Professional Legionella Risk Assessments.
You’ll receive a written report setting out what was assessed, any risks identified (such as dead legs, incorrect temperatures, or stored water issues), and clear, practical recommendations to bring the system into compliance. It’s designed to be kept on file as evidence of compliance with HSE ACOP L8 guidance.
RdSAP 10 collects more detailed data for a more accurate EPC rating. Key changes include:
- Every window is now individually measured and assessed.
- Insulation is recorded by location, type, and thickness.
- Heating systems and renewables are modelled more accurately.
- Ventilation, including extractor fans and flues, is recorded in more depth.
- Air tightness is now part of the modelling, using measured values where available.
Assessments may take slightly longer, but the result better reflects how the property actually performs.
Bluewire Hub provides professional services including Domestic Energy Performance Certificates (EPCs), floor plans, legionella risk assessments, and heat loss calculations. We also offer mentoring for new energy assessors to support career development and business growth. Our services are tailored for landlords, estate agents, homeowners, and businesses seeking reliable, efficient, and accurate assessments.
The four metric structure and the heating system cap come from a government consultation that closed in March 2026. A formal response with confirmed band boundaries is expected later in 2026, so treat specific thresholds as likely rather than final.
Battery storage is recorded as part of the EPC assessment under RdSAP 10, but it usually has little to no effect on the actual rating. EPCs are based on modelled energy costs rather than real usage, so unless a battery is specifically set up to cut electricity demand at peak times, it won’t meaningfully lower the estimated cost used in the calculation.
Batteries paired with solar can be genuinely useful in practice, they just don’t tend to move the needle on your EPC band yet. That could change as time-of-use tariffs and smarter systems become more common.
Knowing whether your floor is solid or suspended affects both heat loss and your insulation options.
A suspended timber floor usually has air vents or air bricks at ground level outside, and can feel slightly springy underfoot. A solid floor, typically concrete, has no vents, feels firm, and is often tiled or screeded with no void space underneath.
Still not sure? A qualified surveyor or energy assessor can confirm your floor type during an inspection, useful to know before choosing an insulation method.
Not necessarily. EPCs remain valid for 10 years from the date they’re lodged. However, if your current EPC is close to Band C and close to expiry, renewing it now under the current methodology can lock in a fresh 10 year certificate before EPC reform changes how ratings are calculated.
A higher EPC rating makes a property more appealing to buyers and tenants, who increasingly weigh up running costs and energy efficiency. It’s also linked to lower bills and better comfort, both of which matter in a competitive market.
Some mortgage lenders now offer better terms for energy-efficient homes. For landlords it’s more than a selling point, from 2025 newly rented properties in England and Wales are expected to need at least an EPC Band C, with fines for non-compliance.
As standards tighten and buyers grow more energy-conscious, properties with poor ratings may become harder to sell or let, so improving your rating now helps future-proof the property.
Yes. Start by contacting the assessor who carried out the survey, most concerns can be resolved with a conversation, and every assessor has a formal complaints process if you need to escalate.
Assessors keep detailed records and evidence from the inspection, so they can clarify or correct entries and reissue the report where appropriate. Bear in mind they can’t take your word alone for disputed items like floor or ceiling insulation, there needs to be documentary evidence.
If it’s still not resolved, you can escalate to the assessor’s accreditation scheme, who can investigate or require a reassessment. It’s worth acting promptly, since your EPC stays valid for 10 years regardless of any ongoing query.
Often, yes, it depends on your floor construction. For a suspended timber floor, insulation can usually be fitted from below via a cellar or crawl space, without lifting floorboards or disturbing your interior finishes.
Solid floors need insulation installed over the existing surface, which can raise the floor level slightly and may mean small adjustments to skirting, doors, or thresholds. It’s generally straightforward and makes a noticeable difference to warmth.
A professional installer will preserve or improve any existing ventilation as required by building regulations, and the work can also help your EPC rating.
Yes. Tablets or iPads allow DEAs to complete reports on-site, reducing paperwork and improving accuracy. Digital tools help prevent errors from re-entering data and support faster reporting. While paper-based methods work initially, upgrading to digital equipment enhances professionalism and client confidence. Tablets also allow access to reference materials, templates, and software tools that make your workflow more efficient. Explore recommended options on our DEA Equipment page.
Cold water should be stored and distributed below 20°C, and hot water should be stored at 60°C or higher at the cylinder and reach at least 50°C at the tap within one minute. Keeping water outside the 20–45°C range legionella bacteria thrive in is one of the main ways a system stays compliant. Read more: Water Temperature and Dead Legs.
Yes. Landlords have a legal duty under the Health and Safety at Work Act 1974 and the COSHH Regulations 2002 to assess and manage legionella risk in their properties, in line with HSE ACOP L8 guidance. Non-compliance can lead to enforcement action, fines, or prosecution.
Expect to pay between ÂŁ96 and ÂŁ175, depending on your property’s location, size, age, and layout. A small flat with simple construction sits at the lower end; a large detached house with multiple heating zones or renewables costs more.
The fee covers pre-visit research, the on-site data collection required under RdSAP 10, and preparing the report afterwards. Watch out for comparison sites advertising low headline prices, a large share often goes to the website rather than the assessor doing the work. Contacting a local accredited assessor directly usually gets you a fairer price and a service tailored to your property.
Exemptions exist for situations such as high cost improvements, third party consent issues, or cases where wall insulation isn’t appropriate for the building. Evidence is required to register any exemption, and most last 5 years, though some run for up to 10.
Estate agents use floor plans to show potential buyers or tenants the property layout. Accurate plans help visualise room sizes, flow, and living space, improving marketing and aiding decision-making.
Appointments can be booked via our website booking form or by calling our office. We aim to offer flexible scheduling to suit your availability and confirm all bookings promptly to ensure your assessment or consultation runs smoothly.
An EPC is the official certificate that gives your property’s current energy rating. A MEES compliance check, like the one on this page, gives you a quick indication of how that rating sits against the upcoming Band C requirement, so you know whether action is needed before booking a full assessment
An EPC shows how energy efficient a home is and is legally required when selling or letting residential property in the UK.
It rates the energy efficiency of a domestic property from A (most efficient) to G (least efficient). It includes estimated energy costs and tailored recommendations for improvement. EPCs are a legal requirement when a home is built, sold, or rented. They help prospective buyers and tenants understand running costs and inform decisions about upgrades and compliance.
Production time varies by property size, but most plans are completed within 3–5 working days. Digital copies are ready for marketing, estate agent listings, or inclusion with EPC certificates.
No. Existing EPCs remain valid for ten years from issue, and the current A to G rating is expected to continue running alongside the new metrics until at least October 2029.
Not under the current rules. Band D meets the existing Band E minimum. However, Band D properties may need attention ahead of 2030, and the amount of work needed depends heavily on the SAP score within that band and the building’s construction type.
Yes. Landlords must provide a valid EPC to tenants before renting. Failure to comply can lead to fines. EPCs also help attract tenants by demonstrating energy efficiency.
Yes. We create personalised mentoring plans to suit experience, business objectives, and learning style, covering technical support, business development, or both.
Yes. Scheduling a floor plan alongside an EPC is efficient, reducing multiple visits and providing a comprehensive overview in one appointment.
A reliable DEA toolkit is essential for accuracy and efficiency. Core items include a laser distance measurer, tape measure, folding carpenter’s ruler, step ladder, extending ladder, torch, dust mask, overshoes, bump cap, glazing gap gauge, pens, graph paper, folders, and a tablet or iPad. Using the right DEA equipment ensures precise measurements, safer inspections, and a smoother workflow. Proper organisation of your DEA equipment also saves time on site and helps maintain professional standards. Explore recommended options on our DEA Equipment page.
Having a smart meter is recorded on your EPC under RdSAP 10, but it doesn’t affect your rating or band. EPCs are based on your building’s construction, insulation, and heating systems, not how you monitor your usage.
A smart meter is noted for reference, similar to solar panels or battery storage, but it has no bearing on the calculated running costs behind your score. It’s important the assessor can access your meters to record the correct type. That could change in future EPC versions as smart energy management becomes more widespread, but for now it’s recorded, not scored.
