Read your window schedule before requesting a quote
Understanding window planning
At first glance, a window schedule can look like a table of abbreviations, dimensions and item numbers. In practice, it determines whether three suppliers are pricing the same specification or merely windows with similar descriptions. Reading it before requesting quotes reveals missing details early: Is the measurement the structural opening, outer-frame size or clear opening? Is the opening direction viewed from inside or outside? Does the U-value apply to the glass or the complete window? Are the shown bars decorative or genuine glazing divisions? These are not formalities. They affect operation, appearance, installation planning and comparability. Work through each item, flag uncertainties and give every supplier the same corrected version. This turns a planning document into a reliable basis for requesting quotations.
Check before requesting a quote 1
Use the window schedule as a shared benchmark
A sound quote request starts with one simple rule: each item number must represent one clearly defined design. For example, F-01 may appear more than once where identical windows are planned in several rooms. The quantity and identical configuration must then be obvious. If just one detail changes, such as the opening side, division, finish or glazing, it normally needs its own item or an expressly documented variation note. Otherwise, one supplier may assume a simplified version while another prices every variation separately. The resulting quotations can appear comparable in total, while their actual scope differs. First highlight every line where a description could allow more than one possible design.
Keep all related documents beside the window schedule: floor plans, elevations, sections, detail drawings where available, and a specification. The schedule often states what is to be supplied; drawings show where the element sits and its context. Do not silently reconcile conflicting information yourself. Note, for example, “F-08: schedule single-leaf, elevation double-leaf” rather than selecting a version independently. For renovation work, also establish whether the list contains existing measurements, design measurements or order sizes checked on site. State which document must be reviewed if information conflicts. This clarification belongs in the quote request, not only at order confirmation stage.
Check item numbers, rooms and quantities
Start with a checklist: every item number should have a location, quantity, element description and traceable drawing reference. Room names are especially useful where sizes repeat. A bathroom window can require different privacy, ventilation and accessibility features from a visually similar living-room window. Without this allocation, an item can be priced but important use requirements remain unanswered. Also check whether doors are included in the same schedule. A patio door is easily grouped under “windows”, yet needs additional information about its threshold, handle side and clear passage. Use consistent room names rather than changing abbreviations from different drawing revisions.
Check quantities not only line by line, but also by building elevation and floor. This can reveal elements missing from an elevation or counted twice by mistake. Identical windows on different façades may share an item where every feature is genuinely the same. If not, separate the items. For a quote request, a single inward-opening window may describe a suitable product type, but that description does not replace the actual size, handing, glass, finish or hardware requirement. Always include the item number. A small control total for each floor also makes later checks against the quotation, order confirmation and delivered scope easier.
Check before requesting a quote 2
Put dimensions into context before comparing
Numbers without a measurement reference are a common source of misunderstanding. Width by height may mean the outer frame size, opening size, structural opening or clear opening. The notation 1,235 × 1,485 mm does not explain this reference by itself. For each item group, ask: which dimension is shown, from which side is it read, and is it a design measurement or one verified on site? For windows with sidelights, fanlights or coupled sections, also establish whether the number is the overall size or the dimensions of individual parts. Record whether the sequence is consistently width × height so rotated figures do not pass unnoticed.
Do not copy dimensions uncritically from a façade elevation when the schedule gives different values. Elevations may be visually simplified, while a schedule may contain a transposed number. Check slopes, arches and special shapes particularly carefully. A fixed triangular or sloping window is defined by its outline geometry; width and height alone do not describe it fully. For these items, request a dimensioned sketch with clear reference points and the location of the slope. Connection details and the intended location of the element within the wall build-up also form part of installation planning. The responsible design professional should assess these matters for the actual installation situation.
Read the view, opening type and handing accurately
A window symbol does not always explain everything. First establish whether the drawing is read from the inside or outside. Only then can left- or right-hand terminology be interpreted reliably. For clarity, also describe in words which side the hinges are on in the stated view and the direction in which the sash opens. For a tilt-and-turn window, include the required operating function. With a double-leaf design, record which sash carries the handle, which opens first and what division is required. If the floor plan and window elevation use different viewing directions, label both clearly instead of relying solely on arrows.
The opening type must suit how the room is used, not merely the façade drawing. An inward-opening sash can conflict with furniture, curtains, fittings or a worktop. An outward-opening sash, on the other hand, needs sufficient clear space outdoors. A double-leaf inward-opening window states the basic opening direction and sash count, but does not automatically answer every detailed question. Mark possible conflicts for each affected element on the floor plan and furniture layout. Also ask whether fixed and moving fields are clearly labelled. A visible division does not reliably show which field can open or which sash is used first in daily life.
Check before requesting a quote 3
Do not confuse fixed glazing with a fixed sash
A window schedule should clearly distinguish fixed glazing from an opening sash. A fixed-glazed element is designed as a non-opening section; it may provide daylight, views or a calm façade composition. A moving sash also provides operation and ventilation. If a room has only fixed glazing, the planned ventilation method must therefore be addressed as a project question. It should not be replaced by an assumption that one field will “probably open somehow”. Also check access for cleaning and maintenance from the intended installation position. With high-level or externally inaccessible fields, this practical issue can affect the chosen division.
For composite elements, a field sketch is especially helpful. Mark, for example, a fixed field on the left, an opening sash in the centre and another fixed field on the right. Add division measurements, or clearly state if the supplier should propose these as an alternative. This prevents a supplier from pricing only the outer overall width while interpreting the internal layout differently. For a purely non-opening design, a window with fixed glazing is an appropriate description. Still check the actual schedule for mullions, transoms, division sizes and glazing bars. For round or arched windows, it should likewise be clear whether the whole shape is fixed glazed or whether adjacent rectangular areas are intended to open.
Use the same reference basis for glazing and U-values
Terms such as double or triple glazing are a starting point, not a complete basis for comparison. State in the quote request which glazing is planned for each item and which additional properties are expressly required, such as privacy, patterned glass or a particular safety specification. A general statement for “all windows” is risky where individual rooms or door panels differ. Create a separate glass column and ask suppliers to confirm unclear requirements. For patterned glass, the designation, required appearance and field allocation should also be unambiguous. Always assess quotations by item: special glazing may be included for just one line even though the summary sounds more general.
The reference basis must be stated for a U-value. A value for the glazing is not automatically the value for the whole window. Ask: which performance value is stated, which specific element and dimensions does it cover, and does it genuinely apply to every quoted item? A Super Low Uw passive-house outward-opening window names a product configuration, but does not replace item-specific confirmation of the required specification and values. Do not compare only one figure. Dimensions, frame proportion, opening sashes, divisions and glazing all shape the assessment of an individual element. Where suppliers use different reference bases or sample dimensions, request an explanation before ranking offers. The energy planning of the complete building should be handled by qualified professionals.
Check before requesting a quote 4
Specify glazing bars precisely, not only with an image
“With glazing bars” is too vague for a quote request. Bars change a window’s appearance, but can be made in different ways. Decorative bars sit on or within the glazing arrangement. True divided-light bars physically divide the glazing and must be specified as such. Also state their number, orientation, position and grid, for example two horizontal bars in the upper section. An elevation image is useful, but cannot replace a written specification. For asymmetrical layouts, give dimensions or understandable reference lines. If the grid should align across several elements, that design intention must be visible in the elevations and described jointly for the affected items.
Check bar layouts separately for fixed fields and opening sashes. A composition that looks symmetrical across the full window elevation can end differently at sash edges, mullions or transoms. Where a historic appearance is intended, assess frame effect, sash division and bar pattern together. A historic-style double-leaf outward-opening casement window can serve as a starting point, but the exact bar design remains a separate specification. Also ask whether drawing and description show the same number. If no bars are wanted, write “without glazing bars” explicitly. This avoids a schematic illustration being understood as a binding division, or a decorative version being quoted where true divided lights were intended.
Record doors fully as separate items
External and patio doors generally need more context in a window schedule than a standard window. Alongside width, height, opening direction and handing, clarify the relationship to the finished floor level, required passage arrangement and handle side. For a door to a patio, the threshold can be decisive for use, but its exact design must not be inferred from a symbol. Record it as a question and coordinate it with the connection and floor design. A door leaf with sidelight is not a simple individual size but an assembly. Clearly state the overall width, divisions, fixed and moving areas, and location of the sidelight.
Large openings require especially clear identification of moving and fixed sections. For Patio Life lift-and-slide doors the schedule should, for example, show which panels are fixed and which move, from which internal view the operating side is defined, and whether dimensions apply to the whole assembly. Add the desired opening side in words and check whether furniture, an external step or an adjoining wall affects use. The same applies to folding or multi-panel solutions. Request an item-specific drawing where the floor plan does not clearly show the travel direction. This ensures every supplier prices the same system and the required opening does not end up on the wrong side because the view was misunderstood.
Check before requesting a quote 5
Allocate finishes, handles and accessories explicitly
A window schedule is ready for quotation only when visible and operational details are not left in general notes. Check the required colour or finish inside and outside where those faces are to differ. Allocate handles, hardware finishes, ventilation accessories, window boards, shutters or other components to specific items. If particular parts are excluded from supply, this can also be recorded as a boundary. Where decisions are missing, request separately priced alternatives rather than allowing the supplier free choice. This keeps the base version comparable. Also check whether a general colour instruction genuinely applies to special shapes, doors and differently designed internal rooms, or whether exceptions need their own lines.
Operating height and accessibility also deserve a check against the floor plan and section. A high-level window may be planned as an top-hung outward-opening fanlight but the request must specify its operation and desired actuator. For inaccessible positions, ask how the element is intended to be used daily instead of defining only its shape. Also document whether insect screens, privacy screening or sun protection need coordination. These components are not automatically part of a window quotation, but may affect space, operation and connections. List separately what is to be quoted, merely prepared for, or designed by another trade. This prevents missing ancillary work from appearing only after the price comparison.
Turn unclear information into a quotation matrix
Rather than sending several emails with individual corrections, prepare a compact quotation matrix. Each line should include item number, room, quantity, measurement reference, element type, opening type, view or handing, glass, bars, finish and outstanding decision. Add a column headed “Supplier to confirm”. Use it for specific questions such as “Understood as outer-frame dimension?” or “Bars priced as decorative or true divided lights?”. Another column can refer to the governing drawing and its revision. The matrix does not replace a drawing, but makes clear which details are binding and which remain open. Send every supplier the same dated version. When questions are answered later, issue a new revision instead of overwriting isolated table cells without a change note.
Request feedback item by item, not only as a total sum. On receipt, check that every item is listed, quantities and measurements are adopted, and alternatives are separately identifiable. A lower quote is not automatically cheaper if an opening type, sidelight, accessory or required glazing is missing. Compare scope first and prices afterwards. For differences, request an understandable list instead of a blanket price adjustment. Bloomcabin windows and doors carry a five-year guarantee. Delivery takes 4–6 weeks, subject to order confirmation. Even so, check the specific order confirmation line by line against the final window schedule and record approved changes.
Frequently asked questions
What is the main difference between a window schedule and a window drawing?
A window schedule assigns items, quantities and properties in a structured way. A drawing shows location, view, shape or installation situation. You need both for a dependable quote request: the schedule enables comparison, while the drawing clarifies spatial relationships and divisions. Conflicts should be resolved in writing before requesting quotations and allocated to a clear drawing revision.
Do I need to state left- or right-hand opening?
This can be useful, but is not always sufficient on its own. Also state the view being considered, for example the internal elevation, and describe hinge side and opening direction in words. For double-leaf windows, the handle side, first-operated sash and intended use should also be clear from the schedule or a field sketch.
Is it enough to give width and height in millimetres?
No. The supplier needs to know what the dimensions refer to, such as outer-frame size, structural opening or clear opening. Special shapes also require dimensioned geometry. State whether dimensions are design measurements or already checked on site, and whether the order is consistently width × height.
How should I describe glazing bars in a quote request?
First name the type: glazing bars for a decorative design, or true divided-light bars for physically separated glass fields. Add the number, horizontal and vertical position, grid, and allocation to fixed field or sash. If no division is wanted, write “without glazing bars” clearly in every affected item.
What if not every detail has been decided yet?
Separate fixed requirements from outstanding decisions. For open points, request clearly marked alternatives rather than silent assumptions. Have the basic version fully priced item by item. You can then compare variations later without retrospectively aligning several quotations or trying to separate unclear lump-sum prices.
Next step
A window schedule is not good because it contains many abbreviations, but because every item can be understood without guesswork. First check quantity, location, drawing revision and measurement reference. Then clarify opening type, handing, fixed and moving fields, glazing and bars. Add finishes, operation and accessories only where they are clearly allocated. A short, visible list of open questions is more valuable than apparent completeness. When every supplier receives the same version-controlled documentation and lists differences by item, you can compare scope and alternatives with purpose. Approve the design only when the window schedule, drawings and order confirmation match.
