{"id":66347,"date":"2024-11-25T12:01:10","date_gmt":"2024-11-25T12:01:10","guid":{"rendered":"https:\/\/megasol.ch\/?p=66347"},"modified":"2026-03-18T08:50:02","modified_gmt":"2026-03-18T08:50:02","slug":"historic-preservation-and-photovoltaics","status":"publish","type":"post","link":"https:\/\/megasol.ch\/en\/historic-preservation-and-photovoltaics\/","title":{"rendered":"Historic preservation and photovoltaics"},"content":{"rendered":"

[vc_row gap=\"4\" background_type=\"\" css=\".vc_custom_1620800416602{margin-bottom: 10px !important;}\"][vc_column width=\"2\/3\" css=\".vc_custom_1664374414296{padding-top: 20px !important;padding-bottom: 20px !important;background-color: #ffffff !important;}\"][vc_custom_heading text=\"Historic preservation and photovoltaics \u2013 a sustainable pair\" font_container=\"tag:h1|text_align:left\" use_theme_fonts=\"yes\" css=\".vc_custom_1731316072270{margin-bottom: 20px !important;}\"][\/vc_column][vc_column width=\"1\/3\"][\/vc_column][\/vc_row][vc_row][vc_column][vc_single_image image=\"66085\" img_size=\"1920x900\" image_hover=\"\"][\/vc_column][\/vc_row][vc_row equal_height=\"yes\" background_type=\"\" css=\".vc_custom_1727442328776{margin-bottom: 10px !important;background-color: #ffffff !important;}\"][vc_column width=\"5\/6\" css=\".vc_custom_1729764349998{padding-top: 20px !important;padding-bottom: 40px !important;}\"][vc_column_text css=\".vc_custom_1731675409840{margin-top: 10px !important;}\"]In May 2024, the listed house in F\u00fcrschwendi, Eggersriet (SG) was equipped with a customised LEVEL<\/a> roof-integrated solar system from Megasol \u2013 a breakthrough after seven years of intensive negotiations with the office for the protection of historical monuments of the Canton of St. Gallen. Thanks to the close cooperation between the installation company and Megasol, a solution was developed that convinced both the municipality and the cantonal office for the protection of historical monuments. This project sets a new standard and serves as a model for the authorisation procedure introduced in the canton of St. Gallen in autumn 2023, which should make similar projects easier in the future.[\/vc_column_text][vc_row_inner css=\".vc_custom_1620800857392{margin-top: 30px !important;}\"][vc_column_inner][vc_column_text css=\".vc_custom_1731675681668{margin-bottom: 30px !important;}\"]<\/p>\n

A new PV system was needed<\/strong><\/h2>\n

Karl B\u00fcchler, the owner of the house in F\u00fcrschwendi<\/a>, had wanted to replace his aging solar thermal system with a larger and more efficient PV system since 2017. After all, there was now a higher demand for solar energy due to, among other things, an air-to-water heat pump and an electric car. The old system was installed on the roof where it was visible to everyone. So it seemed reasonable to assume that approval for a new system would not be a problem. That was far from the truth! The preservation order was interpreted differently. This resulted in a number of challenges regarding the approval. The hamlet of F\u00fcrschwendi is one of Switzerland's nationally significant heritage sites worthy of protection. This means, for example, that traditional materials must be used for renovations, including the roof renovation.[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_row_inner css=\".vc_custom_1731336014927{margin-bottom: 40px !important;}\"][vc_column_inner width=\"1\/2\"][vc_single_image image=\"66139\" img_size=\"full\" image_hover=\"\"][vc_column_text]<\/p>\n

before<\/p>\n

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after<\/p>\n

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Objections of the preservation order<\/strong><\/h2>\n

The old solar system was a rooftop installation for solar thermal energy. A proposed new, larger PV system would have significantly altered the appearance of the roof, which is covered with grey Eternit shingles, making it a conspicuous foreign element. The initial building applications for the new roof-mounted solar system were therefore rejected by the preservation authority, as it would have excessively disrupted the historical aesthetic of the listed ensemble. \u2018First of all, the color didn't match, then the size of the planned PV system. It was difficult to find a compromise with the heritage protection authorities,\u2019 says Karl B\u00fcchler in a report by Schweiz aktuell im SRF.<\/a><\/p>\n

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It was only a cantonal amendment to the law on the protection of historical monuments in 2022 that enabled progress to be made in the approvals process. According to the new approval procedure, the roof landscapes worthy of protection in the canton of St. Gallen are categorised using a traffic light system in red, orange and green. The hamlet of F\u00fcrschwendi is in an orange area and is therefore one of the roof landscapes with high value. On this basis, roof-mounted systems will be possible here in the future, although the preservation order still has a say.<\/p>\n

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In 2023, Karl B\u00fcchler submitted a new application for approval of a solar installation. This was again rejected. However, the preservation order allowed for the application to be reconsidered if a compatible solution were found. This should allow the PV system to blend in better with the appearance of the historic roofs.
\n[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_row_inner css=\".vc_custom_1726833377233{margin-top: 30px !important;margin-bottom: 20px !important;}\"][vc_column_inner][vc_column_text css=\".vc_custom_1731675384008{margin-bottom: 30px !important;}\"]<\/p>\n

The solution<\/strong><\/h2>\n

Karl Streule, managing director of Streule+Alder AG<\/a>, took on this challenge. He had not only planned the project together with the client, but had also been involved in the negotiations with the office for the preservation of historical monuments from the outset. He was familiar with the arguments and reservations. He turned to his partner company Megasol that he had been working successfully with them for years and knew from this experience that he would find not only the right modules for his customers but also ideal support from a partner in his search for a solution.[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_row_inner][vc_column_inner width=\"3\/12\"][vc_single_image image=\"66109\" img_size=\"200x300\" image_hover=\"\"][\/vc_column_inner][vc_column_inner width=\"7\/12\"][vc_column_text]\u2018The preservation authorities were sceptical about installing a photovoltaic system on a listed building,\u2019 explains Karl Streule, managing director of Streule+Adler AG. \u2019But in the end, we were able to convince them with Megasol's custom-made, glare reduced modules. They blend harmoniously into the overall historical picture.\u2019<\/span>[\/vc_column_text][\/vc_column_inner][vc_column_inner width=\"2\/12\"][\/vc_column_inner][\/vc_row_inner][vc_row_inner css=\".vc_custom_1726833377233{margin-top: 30px !important;margin-bottom: 20px !important;}\"][vc_column_inner][vc_column_text css=\".vc_custom_1731321618464{margin-bottom: 30px !important;}\"]He was able to discuss the requirements of the preservation order with his contacts and look for a solution for the implementation. After all, Megasol had the relevant experience, having already installed Megasol solar roofs on a number of historical buildings in recent years. In the case of the house in F\u00fcrschwendi, the roof-integrated solar system LEVEL proved to be the solution.[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_row_inner css=\".vc_custom_1726833377233{margin-top: 30px !important;margin-bottom: 20px !important;}\"][vc_column_inner][vc_column_text css=\".vc_custom_1731675582346{margin-bottom: 30px !important;}\"]<\/p>\n

LEVEL impresses the heritage protection authorities<\/strong><\/h2>\n

To ensure that the modules of the LEVEL<\/a> roof-integrated solar system in \u2018Full Black\u2019 blend in better with the matt-grey Eternit shingles, they were matted in a special process. This meant that, as \u2018ZeroReflect\u2019, they were not only low-reflective and low-dazzle, but the dark, matt grey tone took on the visual characteristics of the Eternit shingle roof and met the requirements of the preservation order. Karl Streule personally presented the samples to the relevant people in the municipality and the heritage protection agency, impressing them with the product. The installation in F\u00fcrschwendi also served as a showcase project for the newly introduced approval process in the canton of St. Gallen, impressing with its harmonious integration.[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_row_inner css=\".vc_custom_1726833377233{margin-top: 30px !important;margin-bottom: 20px !important;}\"][vc_column_inner][vc_column_text css=\".vc_custom_1731675601599{margin-bottom: 30px !important;}\"]<\/p>\n

Installation of the PV system<\/strong><\/h2>\n

Shortly afterwards, installation work began on the south-east facing part of the roof. The small, old system was dismantled over an area of around 97 m\u00b2. In addition, some of the Eternit shingles were removed. The roof was covered with the LEVEL<\/a> roof-integrated solar system in this area. On the upper part of the roof, a total of 40 PV modules were installed at a roof pitch of 40\u00b0 over an area of around 69 m\u00b2, and a further 16 PV modules were installed at a pitch of 35\u00b0 over an area of around 28 m\u00b2. Four fall protection devices and a final snow guard were added to the 56 modules over the entire length of the system. The total yield forecast for the system is 16,928 kWh. The installation itself was carried out quickly: mounting hooks and support plates were mounted on the battens, the sealing rails were screwed on and the modules were inserted. In this way, experienced installers can install 10 m\u00b2 per person-hour.[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_row_inner css=\".vc_custom_1726833377233{margin-top: 30px !important;margin-bottom: 20px !important;}\"][vc_column_inner][vc_column_text css=\".vc_custom_1731675616151{margin-bottom: 30px !important;}\"]Technical data of the solar energy system<\/strong><\/p>\n

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