Koller Hattem B.V.

I would like to express my sincere appreciation for the excellent work you did in the installation of my Intergas boiler. The craftsmanship and professional approach are truly impressive. What was particularly striking was the clear communication prior to installation, which made the whole process even more pleasant. Your dedication to quality and personal attention made this experience extra special. Thanks for not only the flawless installation, but also for the friendly approach.

First of all, we have a difficult roof: steep, flat tiles, east/west orientation with shadow areas (not flat/south). We have extensively compared quotes from about 10 installers in terms of panels (Chinese or German?), inverters, conditions, incl. warranty on installation and reviews and had several inspections. Koller was not the cheapest, but price-wise competitive in terms of specifications (DMEGC 405WP panels, Enphase) and it is nice to call in a well-known local company in case of problems. - What immediately stood out compared to all other companies: Koller's inspection before a quote was made was very extensive. The entire roof was measured. Tim indicated that he will always have a team come for difficult roofs. - A good installation plan is certainly important for us. Many installation plans were similar, but some companies predicted rather high yields or forgot trees. Koller's plans were realistic and insightful (where does a panel yield more/less?). Luuk and Tim patiently thought along and discussed a total of 8 (!) options. The advice was not to cover a certain roof section, but to cover our garden shed (empty conduit pipe laid because the garden was open anyway)! In retrospect, it turns out that the prediction per panel was quite accurate and the installation yields more than predicted. - The installation itself went well and faster than expected, neatly concealed in the meter cupboard. Installers consulted where necessary. The only downside is that damage occurred to a PVC pipe at our pond due to a roof tile that had slid down. This was repaired a day later - fortunately Koller does all kinds of installation work. In the end, we received the latest Enphase IQ8plus inverters that are prepared for a possible battery, better than in the quote. Many thanks for the solid no-nonsense approach to Tim, Luuk and Walter + team! And with that a sincere 5-star rating!

Yes, we finally have solar panels too. And that finally has nothing to do with the delivery time, which is really very reasonable! 24 panels on our shed, which clearly has the best spot on the property. Tim has explained and calculated everything well and everything looks great! The installation went smoothly despite a stormy day! Let the sun shine!

We are very satisfied with the advice given when installing a set of solar panels on our thatched house. Koller came up with the perfect dimensions so that the appearance of the house remained intact and we could still generate our own energy! The delivery time was also faster than initially expected. All in all highly recommended.

Last week, the Koller company installed 15 solar panels with us in Hattem. Lots of sun this week, so a nice yield to charge our car, among other things. And to top it all off, we received a delicious congratulatory pie this morning with a photo of our house on it. Delicious! A thoughtful gesture and excellent and personal service in the start-up process. Thank you Koller!