Initial contact and correspondence with DWL was satisfactory including surveying, specification of the windows and responding to our sales queries. This was a high value and complex installation that needed to be got exactly right. We were let down when DWL failed to deliver our windows on the agreed date and were then told this was our responsibility. We eventually proved, and they accepted, that this was their responsibility, not ours. The installers did an excellent job showing tenacity, diligence, good humour and excellent teamwork. The installation team tidied up satisfactorily both in our flat and immediately outside in the lift lobby. However, after they left, we discovered a small amount of debris on the stairs they had used when removing the old windows. The windows themselves, now installed, are of high quality, look great and surpassed our expectations. We appreciated being contacted by the Sales Manager a few days after installation to check that we were satisfied with the installation and to acknowledge the delay in delivery.