The owners of a 17th-century canal house on the Keizersgracht wanted a complete transformation — a modern luxury family home that preserved every listed heritage feature. The project required Monuments Commission approval for every structural change, foundation reinforcement of 400-year-old wooden piles, and integration of modern building systems into protected masonry walls — all within an 11-month timeline.
The site presented significant engineering challenges: the protected heritage status requiring approval from Monuments Commission for every structural change, original wooden pile foundations needing reinforcement, and the narrow canal-side access limiting construction equipment due to the residential neighbourhood bordering the development zone.
Cornerstone assembled a dedicated team of 28 specialists including heritage architects, structural reinforcement engineers, and specialist subcontractors. We implemented a phased construction methodology that allowed parallel workstreams — foundation underpinning and structural steel insertion proceeded floor-by-floor while heritage timber framing was carefully restored in parallel from the traditional timeline.
Our project management team deployed real-time BIM (Building Information Modelling) coordination, allowing all trades to work from a single digital source of truth. Weekly client walkthroughs and a dedicated online portal gave the stakeholders full visibility into progress, costs, and any emerging decisions.
Achieving BREEAM Excellent required sustainability to be embedded in every decision. We specified underfloor heating connected to a district heat network, heritage-compatible triple glazing that replicates the original window profiles, and a green sedum roof. The building's energy label improved from G to A+, with annual heating costs reduced by 78% compared to the pre-renovation baseline.
Keizersgracht Residence was delivered on schedule and 3% under the original budget — a remarkable achievement for a project of this scale. The building achieved the Monuments Commission commending the quality of restoration, and the residence winning a Heritage Renovation Award nomination.
The residence has become a landmark on the Keizersgracht and has been shortlisted for the Amsterdam Heritage Prize 2024. The client has since engaged Cornerstone for a second canal house renovation on Herengracht.