How to Order Custom Windows and Doors
Planning and Order Approval
A custom order is settled long before checkout: it brings together site measurement, design and installation. A window may fit the opening but still cause trouble if its sash strikes a sill, the divisions do not suit the façade, or the connection to insulation, sill and reveal remains unresolved. Doors also require thought about circulation, thresholds, handles and the transition outdoors. Describe every unit as part of the wider project before comparing options. This guide outlines the information to gather, how to read drawings and which questions can uncover unfinished decisions before a binding approval.
Start with an opening schedule, not individual wishes
Create a single opening schedule for the whole project. Give every window and door a unique reference, such as W-01 or T-03, along with its room, façade location and intended use. Add approximate size, operating type, opening direction, interior and exterior view, plus details such as glazing bars, transoms or sidelights. This quickly reveals, for example, when a room has 2 openings but only 1 needs ventilation. It also prevents identical dimensions from being treated as identical products when their use or appearance differs.
Do not judge alternatives only as individual units. An inward-opening single-sash window may work well in one room when there is enough interior clearance, but it still belongs in a plan that accounts for the sill, curtains, radiators and furnishings. Record what stands in front of each window and who will use it. In a renovation, also note existing conditions that will remain. The schedule should become a checkable record for quotations, drawings, delivery and installation discussions—not simply a wish list.
Record measurements clearly and name the reference planes
For made-to-measure units, width by height is not enough. Establish whether the figure is a structural-opening measurement, finished opening measurement or desired outside dimension of the unit. Measure openings in several places: width at top, middle and bottom, and height at left, centre and right. Note variations, reveal condition and obstacles such as projecting masonry, services or uneven surfaces. State the start and end point of every measurement. Add the date and construction stage, since plaster, linings or removed old components can alter the reference edge. Where an opening is visibly out of square, check diagonals too. Photos labelled with the opening reference and a visible scale can clarify later questions between site, designer and supplier.
The ordered dimension is not automatically the smallest measured figure. Space is needed between the unit and building fabric for the planned installation connection, and that detail affects final size and position. Agree the appropriate dimension with the professional responsible for installation. Height deserves particular attention: is it measured from the current subfloor or the finished floor level? At a door, even a few millimetres in floor build-up can affect sash clearance and the exterior transition. Never copy dimensions from old documents into a new order without checking them.
The opening in the wider project
Read elevations before setting opening directions
Opening direction is a design choice, not merely a product label. First identify the viewpoint from which the elevation is shown. Then mark hinge side, movement path and handle position for every operable unit. Check the drawing against the floor plan and façade: a sash must not block circulation or collide with furniture, sanitary fittings, radiators or another sash. Outward-opening units also need their swing area checked against patios, railings, planters or shading. For questions, a marked sketch showing inside and outside is safer than saying “left-hinged” without a stated viewpoint. A scaled swing arc also shows whether the handle and sash edge will remain reachable. Apply the same care to upper-floor windows where exterior obstructions may be less obvious.
For high or difficult-to-reach openings, another operating type may suit better than a conventional casement. An outward-opening top-hung window is one specific option, but operation must still suit installation height and reach. Ask who will open each unit, how often and for what purpose. Ventilation, cleaning, emergency egress and outdoor access call for different design decisions. If the opening has an egress or other regulated function, have a qualified local professional verify the requirements that apply at the project location rather than relying on a generic answer.
Choose window type for use, not only façade appearance
A balanced façade grid can be attractive, but it does not replace functional planning. Decide which openings genuinely need to operate. In a room with several windows, combining an operable unit with a fixed-glazed window can provide light and views with fewer operating points. Consider first how the exterior face will be reached and what role the opening plays in ventilation and indoor-comfort planning. Also plan future cleaning: glass that cannot be accessed externally may require a different layout from ground-floor glazing. Fixed glazing is not an automatic substitute for an opening window.
At large openings, sash arrangement changes both the elevation and everyday use. 2 sashes can create a wide opening, but introduce a central meeting point and 2 movement zones. A single sash has a different visual effect and requires different clearance when open. On a symmetrical façade, review axes, sill heights and visible frame lines together rather than from an isolated product image. Compare repeated windows side by side: handle positions, transoms or fixed panes can disrupt an intended rhythm even when each unit seems plausible alone. Check interior and exterior elevations as well. A division wanted outside may affect a view or furnishings inside. The window type is properly resolved only when operation, cleaning, light and façade composition work together.
Plan doors as transitions between finished levels
An exterior door does more than connect 2 rooms—or an interior space and the garden; it also brings several trades and finishes together. Before selection, coordinate the interior floor level, exterior surface, waterproofing, drainage and any canopy. Draw the clearance area on both sides. Include furniture, railings, steps, bicycle storage and paths. An outward-opening door needs clear space outdoors; an inward-opening door uses interior space. With a single-sash outward-opening patio door the selected handing must therefore suit both patio and room. A product name cannot replace checking the real surroundings.
The door elevation also needs precise choices. Define hinge side, handle side, desired glazed areas and the relationship to neighbouring windows. At an entrance, a sidelight, transom or solid panel can substantially alter the proportions. Ask not only whether the door fits its opening, but whether it remains comfortable to use when open and whether visitors can naturally reach the handle. Resolve the threshold alongside the connection design rather than after choosing the door leaf. Where accessibility, safety or other project-specific requirements apply, the responsible designer or qualified professional should determine the suitable solution for the site.
Compare sliding and bifold doors through daily use
Wide garden openings can tempt you to focus only on clear passage width. More important is how the unit opens, closes and works with furniture each day. A sliding door needs no sash swing space, but it has fixed and moving areas that must be allowed for in the elevation and use. Decide which side should move, where the handle remains accessible and how curtains, shading or furniture will sit. A Patio Life lift-and-slide door is a sliding-door option; select its configuration according to the intended opening side and desired connection between spaces.
Bifold doors create a different opening character because several panels fold to one side. The folded leaves need a defined parking area, and their operation differs from a sliding door. Outward-opening bifold doors can be an option where the exterior has the required clearance and the interior is to remain as open as possible. Before approval, establish where divisions sit when closed and which opening condition is most common: briefly open for ventilation, partly open for daily use or fully open to connect with outdoors. That answer matters more to the best sash or sliding layout than a single façade photograph.
The opening in the wider project
Consider glazing as a balance of light, view and comfort
Discuss glazing by room and façade orientation rather than as one decision for the entire home. Consider the importance of daylight, outlook, privacy, summer solar gain and views outdoors in each location. A bathroom, workspace and living room may have different priorities. Nearby buildings, trees, canopies and planned curtains also matter. Describe the desired outcome clearly: a seated view, more screening at standing height, daylight in a hall or a visual connection to the garden. That helps designers and suppliers distinguish essential requirements from preferences.
Drawings are especially important for unusual shapes. A fixed triangular and angled window can complete a roof or gable area visually, but raises different questions from a standard rectangular window: where are the visible edges, how does the shape meet adjacent building elements, and how will the exterior be reached? Coordinate glazing with planned shading and interior design before approving dimensions and divisions. If technical values matter to the project, request documentation clearly tied to the selected unit. Compare figures using the same reference basis and configuration rather than treating information from different variants as directly equivalent.
Review finishes, colours and glazing bars as a whole
Colour and finish are often chosen late, although they strongly influence frames, door panels and divisions. Make a coordinated overview of every visible element: windows, entrance and patio doors, sidelights and, where relevant, gates or cladding. Note whether the interior and exterior should have the same appearance. Look at samples and drawings in daylight beside the intended wall, floor or façade materials. A choice that works on one small sample can look different across a broad window wall. In existing buildings, consider which elements remain visible and how new frame lines will sit beside them.
Use terminology accurately: glazing bars are decorative or structural divisions; glass-dividing bars genuinely separate glazing sections. This affects the appearance and should be stated clearly in both drawing and order. Historic-looking windows are therefore more than a colour choice. A historic-style outward-opening “Kombi” casement window should be coordinated with the other units in its sash divisions, operation and façade appearance. Judge the effect from normal viewing distance, not only on an enlarged detail. If a design brief or authority may impose appearance requirements, have their relevance to the specific project checked professionally before approval.
Check drawings actively as the contract basis
The approval drawing turns wishes into a checkable specification. Compare every opening reference with the schedule rather than reading only the overall elevation. Are width and height correct? Is the drawing identified as an interior or exterior view? Are hinges, handles and moving sashes on the intended side? Are fixed panes, mullions, transoms, glazing bars and glass areas correctly shown? For doors, also check the threshold, movement direction and relationship to adjacent construction. Mark uncertainties directly on the document and have them corrected in writing. A verbal recollection is no substitute for a revised, unambiguous drawing.
Also inspect interfaces that may not appear on the window drawing alone, including shutter or shading boxes, sills, internal reveals, façade insulation, waterproofing and electrical connections for planned drives. For example, a single-panel glazed door sidelight must be checked for its position relative to the door leaf and complete entrance opening; its product title says nothing about the remaining connection or design planning. Have dimensions and datum heights compared across plan, section and elevation. Changes after drawing approval may increase cost and coordination. Approve only when questions are answered and corrected documents show the result actually wanted.
Complete approval with a site check
Shortly before approval, compare the order documents with the site. Check whether openings have changed since measurement, whether floor build-ups are final, and whether new services, linings or exterior features have been added. Review each unit: reference, position, dimensions, opening direction, divisions, finish and special features. For large deliveries, a table with columns for checked, open and confirmed can show who must resolve each item—the homeowner, designer or installer. It is particularly important that everyone works from the same current drawing revision.
Also establish the process after approval. Bloomcabin states a 5-year commercial warranty for windows and doors. Delivery is stated as 4–6 weeks, subject to order confirmation. Plan that period alongside construction progress, storage space, access, installation sequence and protection of finished surfaces. Decide who will check quantities, visible damage and opening references at delivery. A complete approval pack containing the schedule, confirmed drawings, colour decisions and relevant contacts makes handover to site much easier. The right time for questions is before the binding order, not on delivery day.
Frequently Asked Questions
Who should be responsible for measuring custom windows and doors?
That depends on the agreed project process. What matters is naming who measures, which reference planes apply and who confirms dimensions before ordering. Coordinate the structural opening, planned connection and finished floor level with the professional responsible for design and installation. Recorded measurements and photos help prevent later identification errors.
What else should I check for an outward-opening door?
Check the full exterior swing area and operation from indoors. A patio, step, railing, furniture, plants and shading must not interfere with use. The door must also remain sensibly accessible inside. Set hinge and handle sides from a labelled elevation, not from a verbal description alone.
Can operable and fixed-glazed windows be combined on one façade?
Yes, provided the combination suits the intended use. First establish which openings are required for ventilation or operation and how exterior faces will remain accessible. Then coordinate elevations, frame lines and divisions. Do not select fixed glazing without considering its effects on use and cleaning.
Which documents should I keep before approval?
Keep an opening schedule, measurement notes, photos of openings, current plans and elevations, approval drawings, finish and glazing decisions, and recorded answers to open questions. Use only the current, clearly dated drawing revision as the working basis. Later questions can then be tied to a traceable decision.
When should I not approve an order?
Wait if dimensions are estimated, finished floor height remains undecided, opening directions have not been checked on plan and elevation, or connection details are unresolved. The same applies to conflicting drawings and unconfirmed special requests. A complete, understandable record aligned with construction progress is needed for sound approval.
Next Step
A dependable custom order comes from checking each decision in the place where the unit will be used. Start with a complete opening schedule, keep site measurements distinct from ordered dimensions, and read elevations alongside floor plans and façade drawings. Coordinate doors with finished floors, exterior surfaces and circulation; for larger openings, test the everyday operating sequence as well as the appearance. The approval drawing should bring dimensions, divisions and opening directions into one controlled record. For a Canadian project, ask the municipal permit office about the proposed work and confirm with the province or territory which code is in force; the National Model Codes are not automatically in force as one rule throughout Canada. Have qualified professionals resolve any remaining connection or technical questions before ordering.
