01 · Challenge
Ridge raising in a continuous terraced row without interruption
The property in Colmschate stood in the middle of a row of twelve identical houses all sharing the same ridge height. The owner wanted to raise the ridge for extra head height in the attic, but the municipality of Deventer set as a condition that the ridge raising connected seamlessly to the adjoining houses. If the raised section was visibly protruding, it would disrupt the street profile. The structural connection with the roof panels of both neighbouring properties also had to be addressed.
02 · Our approach
Same pitch, higher ridge, clean connections
We raised the ridge by 50 centimetres while maintaining exactly the same roof pitch angle as the neighbouring houses. This allows the new roof plane to connect seamlessly at eaves level. We worked out the connection to the roof panels of the neighbouring properties in detail: a flexible lead flashing that ensures rainwater drainage without affecting the party wall. The permit application included a sketch of the full row of roof profiles with the new ridge line drawn in. Deventer approved.
03 · Result
14 m² of attic space and no break in the street profile
The attic now has 14 m² with a standing height of over 2.1 metres. The neighbouring properties noticed nothing of the renovation: the connections were watertight and the facade elevation looks identical to before the renovation, except for the slightly higher ridge line. The municipality granted the permit in 7 weeks. The contractor complimented the detail drawings: everything fit directly and no deviations from the drawings were needed.