{"id":4217,"date":"2025-09-05T09:59:58","date_gmt":"2025-09-05T06:59:58","guid":{"rendered":"https:\/\/katsourisengineering.com\/energy-performance-certificate-epc-what-it-is-when-its-required-how-its-issued\/"},"modified":"2025-09-09T17:05:35","modified_gmt":"2025-09-09T14:05:35","slug":"energy-performance-certificate-epc-what-it-is-when-its-required-how-its-issued","status":"publish","type":"post","link":"https:\/\/katsourisengineering.com\/en\/energy-performance-certificate-epc-what-it-is-when-its-required-how-its-issued\/","title":{"rendered":"Energy Performance Certificate (EPC): what it is, when it\u2019s required & how it\u2019s issued"},"content":{"rendered":"\n

The Energy Performance Certificate (EPC \u2013 \u03a0\u0395\u0391)<\/strong> shows how much energy a home or business premises \u201crequires\u201d for heating, cooling, domestic hot water and lighting. In simple terms, it\u2019s the property\u2019s \u201cenergy ID\u201d<\/strong> ranging from class A+<\/strong> (very efficient) to H<\/strong> (least efficient). If you\u2019re planning a sale, a new lease or a major renovation, you\u2019ll need one.<\/p>\n\n

In this guide, we explain in plain language what an EPC is, when it\u2019s required, what the inspector checks, which documents you\u2019ll need, how the issuance process works, and how you can improve your rating cost-effectively.<\/p>\n\n

What is an Energy Performance Certificate (EPC)?<\/h2>\n\n

An EPC is an official document that records a property\u2019s energy behaviour. It\u2019s not just \u201cpaperwork for contracts\u201d; it highlights where energy is being lost (e.g., uninsulated walls or old windows) and suggests specific improvements. Owners can see which investments make sense, while buyers\/tenants understand what bills to expect.<\/p>\n\n

When is an EPC required?<\/h2>\n\n

In certain cases an EPC is mandatory. If you\u2019re preparing a listing or a contract, it\u2019s best to know early whether you\u2019ll be asked for it, so you avoid delays later.<\/p>\n\n

    \n
  • Sale<\/strong> of a building or a unit (e.g., apartment, office)<\/li>\n\n\n\n
  • New lease<\/strong> of a dwelling or commercial space (EPC details are entered on the lease)<\/li>\n\n\n\n
  • Sale\/lease advertisements<\/strong>: the energy class from the EPC must be stated<\/li>\n\n\n\n
  • Completion of new construction or a major renovation<\/strong>: an EPC is issued\/updated<\/li>\n<\/ul>\n\n

    Are there exemptions?<\/h3>\n\n

    Yes. Some uses are exempt (e.g., specific places of worship or temporary-use buildings). These exceptions mainly concern buildings that are not normally heated\/cooled or have a special use. If in doubt, speak with an energy inspector so you decide correctly without risk.<\/p>\n\n

    How long it lasts and when it must be renewed<\/h2>\n\n

    An EPC is valid for up to 10 years<\/strong>. However, if you carry out a major renovation (e.g., extensive insulation, replacement of heating\/cooling systems, broad energy upgrades), you\u2019ll need a new EPC that reflects the new condition. For a simple lease renewal, a new EPC is not required, provided the current one is still valid.<\/p>\n\n

    \"Energy<\/figure>\n\n

    What the energy inspector checks<\/h2>\n\n

    The inspector visits the property, measures and records specific data. It\u2019s not a \u201cquick look,\u201d but a standardised process that leads to calculations using specialised software (per KENAK \u2013 the Greek Energy Performance of Buildings Regulation).<\/p>\n\n

      \n
    • Envelope<\/strong>: walls\/roofs\/floors, insulation level, thermal bridges<\/li>\n\n\n\n
    • Openings & glazing<\/strong>: frame material, age, thermal break, shading<\/li>\n\n\n\n
    • Systems<\/strong>: heating, cooling, domestic hot water (DHW), controls\/thermostats<\/li>\n\n\n\n
    • Orientation & shading<\/strong>: sun\/wind exposure and existing shading<\/li>\n\n\n\n
    • Use & schedules<\/strong>: dwellings and commercial spaces have different profiles<\/li>\n<\/ul>\n\n

      Documents you\u2019ll need for issuance<\/h2>\n\n

      You don\u2019t need a \u201cperfect\u201d file – just a basic picture. Anything missing can be completed during the site visit.<\/p>\n\n

        \n
      • Floor plan\/drawings or a sketch<\/strong> with accurate square metres (whatever is available)<\/li>\n\n\n\n
      • Ownership details<\/strong> (title deed\/ENFIA form) and building permit number (if any)<\/li>\n\n\n\n
      • System details<\/strong> (boiler\/AC model, capacity, year), any maintenance records<\/li>\n\n\n\n
      • Brief list of interventions<\/strong> (e.g., window replacement, insulation, solar heater, heat pump)<\/li>\n<\/ul>\n\n

        EPC issuance process: step by step<\/h2>\n\n

        When the property\u2019s basic data and a simple floor plan are available, the process is smooth and predictable. The key is having clear information on systems (boiler, air-conditioners, DHW) so calculations are accurate the first time.<\/p>\n\n

        Record use, area and floor, orientation, available plans\/sketches, and any energy interventions already done (e.g., window replacement, insulation, new systems). This helps spot gaps early and plan the site visit properly.<\/p>\n\n

        Site visit & measurements: photographic documentation and detailed recording of the envelope (walls, roof, floors), windows and glazing, shading, and heating\/cooling\/DHW systems\u2014to accurately capture all factors affecting energy performance.<\/p>\n\n

        Modelling & calculations (per KENAK): onsite data are entered and validated; the property\u2019s energy class (A+ to H) is determined along with consumption indicators and the main contributors to losses or loads.<\/p>\n\n

        Issuance & registration: the EPC is issued and registered. The owner receives the certificate and, where useful, concise improvement proposals with priorities. Beyond compliance for adverts, leases or contracts, you gain a clear picture of where spending will truly improve the rating.<\/p>\n\n

        Time & cost: what they depend on<\/h2>\n\n

        Timeframes and pricing aren\u2019t \u201cone-size-fits-all.\u201d They depend on the property type, completeness of information and system complexity.<\/p>\n\n

          \n
        • Time<\/strong>: typically 1\u20133 working days from the site visit, if the file is complete<\/li>\n\n\n\n
        • Cost<\/strong>: affected by use (residential\/commercial), area\/floors, availability of plans, access\/location<\/li>\n\n\n\n
        • Transparency<\/strong>: request a written quote before the site visit with clear steps and timeline<\/li>\n<\/ul>\n\n

          Example (scenario): from site visit to final rating<\/h2>\n\n

          An owner plans to lease an 82 m\u00b2 apartment in South Athens. Before the site visit, key data are gathered: floor, orientation, window type, heating\/cooling system, presence of insulation.<\/p>\n\n

          During the visit, the inspector finds old aluminium frames without thermal break, a south-facing frontage without shading, and a central oil boiler. Measurements of openings and walls are taken, thermal bridges noted, and the equipment is documented.<\/p>\n\n

          In the KENAK-based model, initial results show high losses through the windows and external walls and high summer loads due to the unshaded southern exposure. A realistic initial rating: Class D.<\/p>\n\n

          Scenario A \u2013 minimal intervention<\/strong>: replace windows with thermal-break frames and low-e glazing, add external shutters to the most exposed openings. The simulation predicts an upgrade to Class C with an estimated payback of 6\u20138 years.<\/p>\n\n

          Scenario B \u2013 targeted upgrade<\/strong>: add external insulation on selected elevations and install a heat pump. The simulation indicates an upgrade up to Class B+ with an estimated payback of 8\u201310 years.<\/p>\n\n

          If Scenario A is chosen, after works and EPC re-issuance, a two-class improvement is realistic. Practical impact: a more attractive listing and lower expected operating costs for the tenant.<\/p>\n\n

          Conclusion<\/strong>: Prioritised, technically sound measures can substantially improve the energy class without a full renovation, when they target the critical loss points and main loads.<\/p>\n\n

          \"\"<\/figure>\n\n

          How to raise your energy class (without waste)<\/h2>\n\n

          You don\u2019t always need major works to achieve a meaningful upgrade. Targeted interventions often deliver more per euro invested. Windows first: replacing with thermal-break frames and low-e glazing\u2014installed correctly with proper air-\/water-tightness\u2014significantly reduces losses and condensation, improving comfort and bills.<\/p>\n\n

          Shading: a low-cost way to cut summer loads. Shutters or awnings on south- and west-facing openings reduce overheating and cooling runtime, especially with large windows or continuous solar gains.<\/p>\n\n

          Systems: a modern heat pump, proper thermostat settings and regular maintenance provide measurable savings without extensive envelope works. Where feasible, targeted insulation (e.g., roof, pilotis, exposed fa\u00e7ades) locks in winter-summer load reductions and amplifies the effect of other measures.<\/p>\n\n

          Simple controls: programmable thermostats, zoning and timers curb unnecessary consumption, especially during absence. With the right order of operations (windows\/shading \u2192 settings\/systems \u2192 insulation\/controls), you can achieve a fast, sustainable upgrade without a \u201cheavy\u201d full renovation.<\/p>\n\n

          Common mistakes that cause delays<\/h2>\n\n

          More than half of issues can be avoided with a minimally organised file. Start by confirming accurate areas and a valid floor plan; rough measurements lead to result deviations and needless onsite delays.<\/p>\n\n

          Next, gather basic system information: brand, model, capacity, year of installation and any maintenance records. Equally important is not to omit recent interventions that change the energy picture\u2014window replacement, fa\u00e7ade insulation, heat pump installation. Keep invoices or at least brief notes with dates.<\/p>\n\n

          Finally, before posting any sale or lease advert, make sure the EPC exists and the energy class is explicitly stated. Listings without a class are often rejected or create extra administrative burden, whereas a complete, accurate listing streamlines the process and boosts credibility.<\/p>\n\n

          Frequently Asked Questions (FAQ)<\/h2>\n
          \n
          \n
          \n

          How long is an EPC valid?<\/strong><\/h3>\n
          \n\n

          Up to 10 years, unless a major renovation occurs that changes the energy profile.<\/p>\n\n<\/div>\n<\/div>\n

          \n

          Do I need a new EPC for a lease renewal?<\/strong><\/h3>\n
          \n\n

          No, as long as the current one is valid and no significant upgrades have been made.<\/p>\n\n<\/div>\n<\/div>\n

          \n

          How quickly is it issued?<\/strong><\/h3>\n
          \n\n

          Typically 1\u20133 working days from the site visit, depending on file completeness.<\/p>\n\n<\/div>\n<\/div>\n

          \n

          What about mixed uses (e.g., ground-floor shop with dwellings above)?<\/strong><\/h3>\n
          \n\n

          Separate EPCs are issued per use\/unit.<\/p>\n\n<\/div>\n<\/div>\n

          \n

          Can I improve my class without a full renovation?<\/strong><\/h3>\n
          \n\n

          Yes, targeted actions on windows, shading and systems can yield substantial gains.<\/p>\n\n<\/div>\n<\/div>\n<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"

          The Energy Performance Certificate (EPC \u2013 \u03a0\u0395\u0391) shows how much energy a home or business premises \u201crequires\u201d for heating, cooling, domestic hot water and lighting. In simple terms, it\u2019s the property\u2019s \u201cenergy ID\u201d ranging from class A+ (very efficient) to H (least efficient). If you\u2019re planning a sale, a new lease or a major renovation, […]<\/p>\n","protected":false},"author":5,"featured_media":4211,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[43],"tags":[],"class_list":["post-4217","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-permits-regulations"],"_links":{"self":[{"href":"https:\/\/katsourisengineering.com\/en\/wp-json\/wp\/v2\/posts\/4217","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/katsourisengineering.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/katsourisengineering.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/katsourisengineering.com\/en\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/katsourisengineering.com\/en\/wp-json\/wp\/v2\/comments?post=4217"}],"version-history":[{"count":0,"href":"https:\/\/katsourisengineering.com\/en\/wp-json\/wp\/v2\/posts\/4217\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/katsourisengineering.com\/en\/wp-json\/wp\/v2\/media\/4211"}],"wp:attachment":[{"href":"https:\/\/katsourisengineering.com\/en\/wp-json\/wp\/v2\/media?parent=4217"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/katsourisengineering.com\/en\/wp-json\/wp\/v2\/categories?post=4217"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/katsourisengineering.com\/en\/wp-json\/wp\/v2\/tags?post=4217"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}