{"id":41571,"date":"2026-03-15T19:17:14","date_gmt":"2026-03-15T18:17:14","guid":{"rendered":"https:\/\/rebotherm.de\/heat-pump-not-possible-in-existing-buildings\/"},"modified":"2026-03-16T10:36:28","modified_gmt":"2026-03-16T09:36:28","slug":"heat-pump-not-possible-in-existing-buildings","status":"publish","type":"page","link":"https:\/\/rebotherm.de\/en\/heat-pump-not-possible-in-existing-buildings\/","title":{"rendered":"Heat pump not possible in existing buildings"},"content":{"rendered":"<p>[et_pb_section fb_built=&#8221;1&#8243; _builder_version=&#8221;4.27.6&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_row _builder_version=&#8221;4.27.6&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_column type=&#8221;4_4&#8243; _builder_version=&#8221;4.27.6&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_code _builder_version=&#8221;4.27.6&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;]<\/p>\n<section style=\"max-width:1100px;margin:0 auto;padding:30px 20px;\"><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] -->  <\/p>\n<header style=\"margin-bottom:28px;\"><!-- [et_pb_line_break_holder] -->    <\/p>\n<h1 style=\"margin:0 0 14px;line-height:1.15;\">Heat pump not possible in existing buildings? Which alternatives are truly sensible <\/h1>\n<p><!-- [et_pb_line_break_holder] -->    <pee style=\"font-size:18px;line-height:1.7;margin:0 0 12px;\"><!-- [et_pb_line_break_holder] --> Many property owners today first plan with a heat pump \u2013 and only in the second step realize<!-- [et_pb_line_break_holder] --> that their own building is not ideally suited for it. Especially in existing buildings, this is not uncommon. Missing large heating surfaces,<!-- [et_pb_line_break_holder] --> challenging floor plans, high necessary system temperatures, historical preservation regulations, or insufficient space for outdoor units and technology<!-- [et_pb_line_break_holder] --> lead to a heat pump being implementable only with great effort or not at all sensibly.  <!-- [et_pb_line_break_holder] -->    <\/pee><!-- [et_pb_line_break_holder] -->    <pee style=\"font-size:18px;line-height:1.7;margin:0;\"><!-- [et_pb_line_break_holder] --> One thing is particularly important then: <strong>&#8220;Heat pump not possible in existing buildings&#8221; does not mean that no modern heating solution is possible.<\/strong><!-- [et_pb_line_break_holder] --> On the contrary \u2013 especially in existing buildings, it is worth looking at alternatives that better suit the existing building structure,<!-- [et_pb_line_break_holder] --> the room geometry, and the renovation goal.<!-- [et_pb_line_break_holder] -->    <\/pee><!-- [et_pb_line_break_holder] -->  <\/header>\n<p><!-- [et_pb_line_break_holder] -->[\/et_pb_code][et_pb_image src=&#8221;https:\/\/rebotherm.de\/wp-content\/uploads\/2026\/03\/altbau-heizkeller-oelheizung-rohrsystem.jpg&#8221; alt=&#8221;Heat pump not possible in existing buildings \u2013 alternative heating solution for existing properties&#8221; title_text=&#8221;old-building-boiler-room-oil-heating-pipe-system&#8221; _builder_version=&#8221;4.27.6&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][\/et_pb_image][et_pb_code _builder_version=&#8221;4.27.6&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;]<pee style=\"line-height:1.75;\"><!-- [et_pb_line_break_holder] -->In many existing buildings, classic heating systems with relatively high flow temperatures are still in operation. <!-- [et_pb_line_break_holder] -->The old radiators and pipe systems were originally designed for heating water with <!-- [et_pb_line_break_holder] -->temperatures of approximately <strong>60 to 75 \u00b0C<\/strong> to flow through the system. These high temperatures <!-- [et_pb_line_break_holder] -->ensure that sufficient heat is released into the room even at cold outdoor temperatures. This quickly leads to the conclusion that a heat pump is not possible in existing buildings.  <!-- [et_pb_line_break_holder] --><\/pee><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] --><pee style=\"line-height:1.75;\"><!-- [et_pb_line_break_holder] -->This is precisely where a typical challenge for heat pumps in existing buildings lies. <!-- [et_pb_line_break_holder] -->Heat pumps operate particularly efficiently when they are run at significantly lower system temperatures <!-- [et_pb_line_break_holder] -->\u2013 often in the range of approximately <strong>30 to 45 \u00b0C<\/strong>. <!-- [et_pb_line_break_holder] -->For these lower temperatures to be sufficient, the building either needs very large <!-- [et_pb_line_break_holder] -->heating surfaces or a significantly reduced heating load.<!-- [et_pb_line_break_holder] --><\/pee><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] --><pee style=\"line-height:1.75;\"><!-- [et_pb_line_break_holder] -->However, in many older buildings, these conditions are not met, and a heat pump in existing buildings is not possible.<!-- [et_pb_line_break_holder] -->The existing radiators are relatively small, the building envelope is only partially insulated <!-- [et_pb_line_break_holder] -->and the heating system was originally designed for higher temperatures. <!-- [et_pb_line_break_holder] -->In such cases, either the entire heating surface structure would have to be changed <!-- [et_pb_line_break_holder] -->or a completely new heating concept would have to be planned.<!-- [et_pb_line_break_holder] --><\/pee><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] --><pee style=\"line-height:1.75;\"><!-- [et_pb_line_break_holder] -->This is precisely why it is often worthwhile in existing buildings to also consider <strong>alternative heating solutions without a heat pump<\/strong> <!-- [et_pb_line_break_holder] -->\u2013 especially systems that work with large-area heat emission and can be <!-- [et_pb_line_break_holder] -->better integrated into the existing building structure.<!-- [et_pb_line_break_holder] --><\/pee>[\/et_pb_code][et_pb_code _builder_version=&#8221;4.27.6&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;] <\/p>\n<h2>Heat pump not possible in existing buildings \u2013 what does that mean specifically?<\/h2>\n<p><!-- [et_pb_line_break_holder] --> [\/et_pb_code][et_pb_image src=&#8221;https:\/\/rebotherm.de\/wp-content\/uploads\/2026\/03\/vorlauftemperatur-altbau-heizung-vs-waermepumpe-diagramm.jpg&#8221; alt=&#8221;flow-temperature-old-building-heating-vs-heat-pump-diagram.jpg&#8221; title_text=&#8221;flow-temperature-old-building-heating-vs-heat-pump-diagram&#8221; _builder_version=&#8221;4.27.6&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][\/et_pb_image][et_pb_code _builder_version=&#8221;4.27.6&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;] <pee><!-- [et_pb_line_break_holder] --> In public discourse, the heat pump is often presented as the standard solution. In many buildings, it is. <!-- [et_pb_line_break_holder] --> In existing buildings, however, suitability depends heavily on the actual conditions. If large heating surfaces are missing,<!-- [et_pb_line_break_holder] --> high flow temperatures are necessary, or the building envelope can only be improved to a limited extent,<!-- [et_pb_line_break_holder] --> the technical and economic effort quickly increases. <!-- [et_pb_line_break_holder] -->  <\/pee><!-- [et_pb_line_break_holder] -->  <\/p>\n<ul style=\"line-height:1.8;\"><!-- [et_pb_line_break_holder] -->    <\/p>\n<li>Insufficiently large areas for low system temperatures are available<\/li>\n<p><!-- [et_pb_line_break_holder] -->    <\/p>\n<li>The floor should not be opened or rebuilt<\/li>\n<p><!-- [et_pb_line_break_holder] -->    <\/p>\n<li>Ceiling height is limited<\/li>\n<p><!-- [et_pb_line_break_holder] -->    <\/p>\n<li>Outdoor units are problematic aesthetically or structurally<\/li>\n<p><!-- [et_pb_line_break_holder] -->    <\/p>\n<li>Historical preservation or sensitive facades restrict implementation<\/li>\n<p><!-- [et_pb_line_break_holder] -->    <\/p>\n<li>The planned renovation is to be carried out gradually and not as a complete overhaul<\/li>\n<p><!-- [et_pb_line_break_holder] -->    <\/p>\n<li>Many existing building heating systems operate with flow temperatures above 60 \u00b0C.<\/li>\n<p><!-- [et_pb_line_break_holder] -->  <\/ul>\n<p><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] -->  <pee><!-- [et_pb_line_break_holder] --> Precisely in such situations, a solution is needed that does not just look good on paper,<!-- [et_pb_line_break_holder] --> but actually works in the real building.<!-- [et_pb_line_break_holder] -->  <\/pee>[\/et_pb_code][et_pb_image src=&#8221;https:\/\/rebotherm.de\/wp-content\/uploads\/2026\/03\/waermepumpe-altbau-probleme-alternative-heizung-diagramm.jpg&#8221; alt=&#8221;Diagram with three reasons why heat pumps can be difficult in existing buildings&#8221; title_text=&#8221;3 reasons why heat pumps can be difficult in existing buildings&#8221; _builder_version=&#8221;4.27.6&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][\/et_pb_image][et_pb_code _builder_version=&#8221;4.27.6&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;]  <\/p>\n<h2>Alternative heating solutions without a heat pump<\/h2>\n<p><!-- [et_pb_line_break_holder] -->  <pee><!-- [et_pb_line_break_holder] --> If a heat pump does not seem sensible in an existing building, the decision should not be made impulsively.<!-- [et_pb_line_break_holder] --> A brief technical preliminary check is useful, clarifying the most important questions:<!-- [et_pb_line_break_holder] -->  <\/pee><!-- [et_pb_line_break_holder] -->  <\/p>\n<ul style=\"line-height:1.8;\"><!-- [et_pb_line_break_holder] -->    <\/p>\n<li>What is the actual heating load?<\/li>\n<p><!-- [et_pb_line_break_holder] -->    <\/p>\n<li>Which areas are available for heat emission?<\/li>\n<p><!-- [et_pb_line_break_holder] -->    <\/p>\n<li>How much intervention into the existing structure is desired or possible?<\/li>\n<p><!-- [et_pb_line_break_holder] -->    <\/p>\n<li>Is a phased renovation planned?<\/li>\n<p><!-- [et_pb_line_break_holder] -->    <\/p>\n<li>How much does insulation influence overall economic viability?<\/li>\n<p><!-- [et_pb_line_break_holder] -->  <\/ul>\n<p><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] -->  <pee><!-- [et_pb_line_break_holder] --> Only when these points have been clarified can a serious assessment be made as to which alternative to a heat pump in an existing building<!-- [et_pb_line_break_holder] --> is truly sensible. This is often where it becomes clear that surface heating in combination with a targeted insulation strategy<!-- [et_pb_line_break_holder] --> can have very convincing advantages in existing properties. <!-- [et_pb_line_break_holder] -->  <\/pee><!-- [et_pb_line_break_holder] -->[\/et_pb_code][et_pb_code _builder_version=&#8221;4.27.6&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;]<\/p>\n<section style=\"background:#f7f7f7;border:1px solid #e5e5e5;border-radius:14px;padding:20px;margin-top:28px;\"><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] --><pee style=\"margin:0;font-size:16px;line-height:1.7;\"><!-- [et_pb_line_break_holder] -->This page is part of our guide on  <!-- [et_pb_line_break_holder] --><a href=\"https:\/\/rebotherm.de\/en\/altbauheizung-ohne-heizkoerper\/\" style=\"color:#009DDF;font-weight:600;text-decoration:none;\"><!-- [et_pb_line_break_holder] -->Old Building Heating without Radiators<!-- [et_pb_line_break_holder] --><\/a>. <!-- [et_pb_line_break_holder] -->There you will find further solutions for typical challenges in existing buildings \u2013 <!-- [et_pb_line_break_holder] -->from missing underfloor heating to historical preservation and alternative heating systems,<!-- [et_pb_line_break_holder] -->when a heat pump is not sensibly implementable.<!-- [et_pb_line_break_holder] --><\/pee><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] --><\/section>\n<p>[\/et_pb_code][et_pb_code _builder_version=&#8221;4.27.6&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;] <\/p>\n<h2>Conclusion<\/h2>\n<p><!-- [et_pb_line_break_holder] -->  <pee><!-- [et_pb_line_break_holder] --> An unsuitable heat pump is not a setback, but an indication that the building needs a different solution.<!-- [et_pb_line_break_holder] --> Those who take the initial situation in existing buildings seriously often find modern alternatives that better suit the substance,<!-- [et_pb_line_break_holder] --> the available space, and the desired comfort. The decisive factor is not to consider just one technology,<!-- [et_pb_line_break_holder] --> but the entire property. <!-- [et_pb_line_break_holder] -->  <\/pee><!-- [et_pb_line_break_holder] -->  <pee><!-- [et_pb_line_break_holder] --> Especially when there is no underfloor heating, no screed is to be installed, or the heat pump<!-- [et_pb_line_break_holder] --> fails due to structural limitations, object-specific planning is worthwhile.<!-- [et_pb_line_break_holder] -->  <\/pee><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] -->  <\/p>\n<section style=\"text-align:center;border-top:1px solid #eee;padding:28px 20px 0 20px;margin-top:26px;\"><!-- [et_pb_line_break_holder] -->    <\/p>\n<h2 style=\"margin:0 0 12px;\">Have us check which alternative suits your existing building<\/h2>\n<p><!-- [et_pb_line_break_holder] -->    <pee style=\"line-height:1.7;margin:0 0 14px;\"><!-- [et_pb_line_break_holder] --> Get a concrete assessment of which heating solution is technically and economically sensible for your building.<!-- [et_pb_line_break_holder] -->    <\/pee><!-- [et_pb_line_break_holder] -->    <pee style=\"margin:0 0 12px;\"><!-- [et_pb_line_break_holder] -->      <a href=\"https:\/\/rebotherm.de\/en\/project-request\/\"><strong>To project planning<\/strong><\/a><!-- [et_pb_line_break_holder] -->    <\/pee><!-- [et_pb_line_break_holder] -->    <pee style=\"margin:0;\"><!-- [et_pb_line_break_holder] --> Or by email: <a href=\"mailto:kontakt@rebotherm.de\">kontakt@rebotherm.de<\/a><!-- [et_pb_line_break_holder] -->    <\/pee><!-- [et_pb_line_break_holder] -->  <\/section>\n<p><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] -->  <\/p>\n<section style=\"margin-top:34px;\"><!-- [et_pb_line_break_holder] -->    <\/p>\n<h2>Frequently Asked Questions<\/h2>\n<p><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] -->    <\/p>\n<h3>Does &#8220;heat pump not possible in existing buildings&#8221; mean the house is technically unsuitable?<\/h3>\n<p><!-- [et_pb_line_break_holder] -->    <pee><!-- [et_pb_line_break_holder] --> Not necessarily. Often it only means that the effort would be too high in relation to the building situation<!-- [et_pb_line_break_holder] --> or that other solutions are more sensible for the specific property. <!-- [et_pb_line_break_holder] -->    <\/pee><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] -->    <\/p>\n<h3>Which alternative is most frequently interesting in existing buildings?<\/h3>\n<p><!-- [et_pb_line_break_holder] -->    <pee><!-- [et_pb_line_break_holder] --> That depends on the initial situation. However, surface heating without classic floor construction,<!-- [et_pb_line_break_holder] --> i.e., solutions via walls or ceilings, are particularly often relevant. <!-- [et_pb_line_break_holder] -->    <\/pee><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] -->    <\/p>\n<h3>Can internal insulation influence the choice of heating system?<\/h3>\n<p><!-- [et_pb_line_break_holder] -->    <pee><!-- [et_pb_line_break_holder] --> Yes. When heat losses are reduced, the heating load decreases. This can significantly improve the economic viability and technical<!-- [et_pb_line_break_holder] --> feasibility of alternative heating solutions.  <!-- [et_pb_line_break_holder] -->    <\/pee><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] -->    <\/p>\n<h3>What is the first sensible step?<\/h3>\n<p><!-- [et_pb_line_break_holder] -->  <!-- [et_pb_line_break_holder] -->      <pee style=\"line-height:1.5;\"><!-- [et_pb_line_break_holder] -->A successful heating modernization in an existing building should always be considered in the context of the <!-- [et_pb_line_break_holder] -->entire building situation. In addition to the choice of heating system, <!-- [et_pb_line_break_holder] -->insulation, windows, heating surfaces, and the overall energy concept also play an important role. <!-- [et_pb_line_break_holder] --><\/pee><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] --><pee style=\"line-height:1.5;\"><!-- [et_pb_line_break_holder] -->A good overview of possibilities for energy-efficient renovation is offered, for example, by the <!-- [et_pb_line_break_holder] --><a href=\"https:\/\/www.dena.de\/projekte\/projektarchiv\/sanierungskampagne-die-hauswende\/\" target=\"_blank\" rel=\"noopener\"><!-- [et_pb_line_break_holder] -->&#8220;Die Hauswende&#8221; renovation campaign by the German Energy Agency (dena)<!-- [et_pb_line_break_holder] --><\/a>. <!-- [et_pb_line_break_holder] -->The initiative informs homeowners about various measures for building modernization <!-- [et_pb_line_break_holder] -->\u2013 from efficient heating technology to thermal insulation, funding opportunities, and energy consulting.<!-- [et_pb_line_break_holder] --><\/pee><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] --><pee style=\"line-height:1.5;\"><!-- [et_pb_line_break_holder] -->Especially in existing buildings, it often becomes clear that not just a single heating system should be considered,<!-- [et_pb_line_break_holder] --> but a coordinated overall concept of heating technology, insulation, and <!-- [et_pb_line_break_holder] -->building optimization is sensible.<!-- [et_pb_line_break_holder] --><\/pee><!-- [et_pb_line_break_holder] -->    <\/pee><!-- [et_pb_line_break_holder] -->  <\/section>\n<p><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] --><\/section>\n<p>[\/et_pb_code][et_pb_code _builder_version=&#8221;4.27.6&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;]<\/p>\n<div style=\"margin-top:26px;padding:20px;border:1px solid #e5e5e5;border-radius:14px;background:#fafafa;text-align:center;\"><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] -->  <pee style=\"font-size:18px;margin:0 0 12px;\"><!-- [et_pb_line_break_holder] --> Are you unsure which heating solution makes sense for your existing building?<!-- [et_pb_line_break_holder] --> Many property owners face precisely this question.<!-- [et_pb_line_break_holder] -->  <\/pee><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] -->  <a href=\"https:\/\/rebotherm.de\/en\/contact-us\/\" style=\"display:inline-block;background:#009DDF;color:#fff;padding:14px 26px;border-radius:10px;text-decoration:none;font-weight:700;font-size:16px;\"><!-- [et_pb_line_break_holder] --> Inquire about existing building heating solutions<!-- [et_pb_line_break_holder] -->  <\/a><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] --> <!-- [et_pb_line_break_holder] -->  <\/pee><!-- [et_pb_line_break_holder] --><!-- [et_pb_line_break_holder] --><\/div>\n<p>[\/et_pb_code][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"class_list":["post-41571","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/rebotherm.de\/en\/wp-json\/wp\/v2\/pages\/41571","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rebotherm.de\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/rebotherm.de\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/rebotherm.de\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/rebotherm.de\/en\/wp-json\/wp\/v2\/comments?post=41571"}],"version-history":[{"count":1,"href":"https:\/\/rebotherm.de\/en\/wp-json\/wp\/v2\/pages\/41571\/revisions"}],"predecessor-version":[{"id":41572,"href":"https:\/\/rebotherm.de\/en\/wp-json\/wp\/v2\/pages\/41571\/revisions\/41572"}],"wp:attachment":[{"href":"https:\/\/rebotherm.de\/en\/wp-json\/wp\/v2\/media?parent=41571"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}