Hi,
We have a small extension being added to the rear of our house. The house was built on a suspended floor but the extension is solid base. Part of the prep work was removing the suspended floor from the existing dining room to accommodate the extension.
The builder notified us that the height they have raised the extension floor to will be 40mm shy of the existing floorboards on the rest of the ground floor.
They asked us to cover the cost of the extra screed to raise it to the correct level, or have a threshold to bridge the gap.
The architect drew the plans up for the floors to be level and have the new DPC match the existing DPC.
The builder matched the DPC height and screeded based on that, and is blaming the architect.
Imo, this is due diligence issue for the builder as they could clearly see the floorboards under the living room doorway, but would welcome any counter points, especially from any builder or architect.
Thanks.
(edited for clarity re suspended floor)