The Room Study

Plan the open curtain first.

This is a planning record, not an order form. Keep your measurements in one unit; the printed examples use centimetres.

Room / windowDate

My unit: cm inchesNo automatic conversions.

1. Draw the space you can use

Opening widthOpening heightSill above floor

Usable wall on leftUsable wall on rightSpace above opening

Sill projects from wallHandle projects from wall

Include trim, doors and furniture. Open each sash or casement fully before deciding where the fabric can hang.

Pair, centre opening Unequal pair One-way left One-way right Blind

Sketch the hardware route, closed position, open stacks and obstacles. For a bay, draw the room in plan.

2. Compare folded width and depth

Proposed heading / hardwareFabric / lining / interlining

Maker’s left stack widthMaker’s right stack widthFolded depth

Left parking space minus stackRight parking space minus stack

A negative result is the amount extending beyond that parking space. Check whether it covers glass, a handle or a doorway. Depth is a separate fit check.

Guide example: 50cm parking − 43.2cm nominal stack = 6.8cm spare. An optional 9.5cm extension makes the stack 52.7cm, covering 2.7cm of glass. This is SG 6840 data, not a universal allowance.

Accessories included in estimate / maker confirms dimensions

3. Check the amount of cloth

For a simple ready-made comparison: combined flat panel widths ÷ covered span = fullness. Example: (180 + 180) ÷ 240 = 1.5. Do not apply this to an already pleated finished width.

Flat width per panelNumber of panelsCoverage span

Calculated fullnessIs the listed width one panel or the pair?

For made-to-measure, send the width requested by the maker. Confirm who adds fullness, overlaps and returns; do not double the order width yourself.

The Room Study

Resolve the route, then the drop.

Room / windowUnit copied from page 1: cm or inches

4. If there is a bay

Treatment follows the bay Curtain across the mouth One blind per face

Across-mouth curtains put the bay behind the closed fabric. For a rectangular bay, width × depth gives that floor area; other shapes need their own calculation. Following curtains need a clear route past every bend and support.

What remains usable with treatment closed?

Each curtain’s start, finish and parking position

5. Choose the drop’s starting point

These are John Lewis examples. Follow the exact supplier’s instructions for the selected heading and hardware.

Arrangement	Example measuring datum
Track	Top of track.
Pencil pleats on rings	Small attachment eye below the pole ring.
Eyelets on a pole	Top of pole; agree who adds fabric above it.
Wave / other system	Confirm the specified point for that exact system.

Confirmed drop starting pointHem position: sill / floor / other

Fitted track run, or pole excluding finials

OverlapReturnIncluded in order width?

Drop at leftDrop at centreDrop at right

Fit hardware before final measuring unless the supplier’s process says otherwise. Retain all drop readings, including extra bay sections, and confirm which measurement to order.

6. Finish the specification

Heater type / exact model, or none

Manual page / required clearance and airflow rule

Check fabric both open and closed. No standard radiator gap is assumed. Confirm suitable fixings and load; follow the product’s cord-safety instructions. The US CPSC recommends cordless coverings where young children are present.

Travel past supports works Stacks and depth fit Handles and openings clear Heat requirements met Cord safety resolved

Supplier adds fullness / heading allowance / other

Final order widthFinal order dropSingle / pair / other

Supplier confirms these are the required order measurements / date

References: John Lewis measuring guide; Silent Gliss SG 6840, April 2026, p8; Poles & Blinds bay components; US CPSC cord safety. Checked 23 October 2026. Keep the confirmed specification with this record.