A floor contains several layers. Its finished height affects doors, stairs, kitchen units and transitions.
What the drawing needs to explain
Draw one section through the kitchen, glazing and terrace. Include finished floor levels, the roof edge and shading position; separate supplier sketches do not fully show these relationships.
Agree a reference level
Use one datum for everyone and record existing and proposed finished heights. Rough construction dimensions are not necessarily ordering dimensions.
Follow the route through the house
A small step can be inconvenient or prevent a door working. Check the hall, bathroom, stairs and outside transitions.
How to review the result
At completion, walk from the cooking area to the terrace. Check the opening with the intended furniture in place and review the light with any shading closed.
Which trade-off matters?
A wide garden opening takes away wall space for cupboards. Compare a fully glazed rear wall with a smaller opening and a targeted rooflight, looking at both from the same seat.
A situation to test your plan against
Imagine extending the kitchen while keeping the dining table inside the original house. The addition should also bring useful light to that table. Include the existing room and the place where you read or work in the daytime.
Questions for your own property
- Are finishes included in heights?
- Do doors and stairs still work?
- Are all floor layers known?
Illustrative design situations, not evidence of completed work. Assess decisions against the actual property.