Why can two quotations for what looks like the same custom door differ by as much as three hundred percent?

Because a custom door is priced by measurable specification variables rather than by appearance. The main cost drivers are the material family (extruded aluminum alloy, cast aluminum panels, steel or wrought iron, or timber), the frame profile wall thickness (typically 1.8–3.0 mm), the panel or plate thickness (1.5–3.0 mm sheet), the core filling (aluminum honeycomb, PU foam, or rock wool), the glazing (5–12 mm tempered or laminated), the locking system, and the finish. Material choice alone usually accounts for 35–55% of the factory cost, so a supplier using thinner walls, injected foam instead of honeycomb, or a basic powder coat instead of PVDF can quote far lower for a door that looks identical in a photograph.

Which material is the best choice for a villa exterior door on a coastal or high-humidity site?

Aluminum systems are generally the strongest choice for villa exteriors. Extruded aluminum alloy (typically 6063-T5 or 6061) offers natural corrosion resistance, dimensional stability, and consistent wall thickness, so it will not rust even with salt air and driving rain, provided fixings and hinges are also stainless steel or aluminum. It also carries wide single-leaf gates and tall entries without the bracing that ironwork needs, can be cut to millimetre tolerances for out-of-square openings, and allows channels for cabling, LED strips, and lock bodies to be designed into the profile. Maintenance is limited to a wash with mild detergent about twice a year. Steel and wrought iron cost less up front but need hot-dip galvanizing plus a multi-coat paint system to avoid rust at welds and drainage points, while timber needs refinishing every two to three years in exposed positions.

What specification details should I confirm with a supplier before placing a deposit?

Ask for the specific alloy designation and the measured wall thickness of the profile they actually intend to use, not a catalog average. Confirm the panel or plate thickness, the core filling type, the glazing type and thickness, the hinge type, and the total finished door weight, since hardware rated below the finished leaf weight is the most common cause of sagging in the first year. For a smart fingerprint lock, confirm the reinforced lock box, concealed wiring, power route, emergency power method, and whether it integrates with your building management system. Request wind-load and water-tightness test reports if the door faces an exposed elevation, ask for a physical finish sample from the actual coating line rather than a printed colour chip, and clarify the warranty split, because surface finish, structural frame, hardware, and electronic components often carry different terms.

What costs are commonly left out of a factory door quotation?

Factory quotes frequently exclude freight, crane offloading, installation labour, duty, and site welding. Custom colour matching to a facade sample may also carry a setup charge, and options such as PVDF coating, anodizing, wood-grain sublimation, non-standard opening directions, LED decoration with its driver and weatherproof junction, and a transom lintel are often quoted separately or omitted entirely. Ask specifically what is excluded, request each option as a separate line item, and agree on a production and shipping schedule in writing that aligns with your site readiness date.

How can I compare custom door suppliers fairly?

Bring the same specification sheet to every vendor and ask the same questions about exclusions and warranties. Measure the structural opening at the top, middle, and bottom, and give every supplier the smallest figure. Require each option — finish, colour, opening direction, smart lock, LED decoration, transom lintel — to be quoted as its own line so you can see exactly where the price differences come from. Confirm hardware brands and that they are rated for the finished leaf weight, ask for test reports for exposed elevations, and check the warranty terms for finish, frame, hardware, and electronics separately. When a supplier can explain each variable in measurable terms, you can judge whether a quotation is genuinely competitive rather than simply cheap.

Custom Doors: Price Factors to Discuss Before Ordering

October 14, 2026

Custom doors are one of the few building components where two quotations for what looks like the same doorway can differ by three hundred percent. Buyers arrive with a familiar set of worries: will the gate survive salt air and driving rain without rusting, how much maintenance will it demand over a decade, can the factory really build to an irregular opening, and who pays if the frame does not match the concrete reveal on delivery day. Security sits underneath all of it, because a villa entrance is a visible point of access that has to resist forcing rather than simply photograph well. Price sits on top. This guide breaks down the material, structural, and finish decisions that move a quotation, so you can compare suppliers on identical terms.

Core Materials and What They Contribute to Price

Material choice is the single largest line item in any custom door quotation, and it usually accounts for 35–55% of the factory cost. The four families buyers encounter most often behave very differently.

Extruded aluminum alloy: Typically 6063-T5 or 6061, chosen for consistent wall thickness, dimensional stability, and natural corrosion resistance. Extrusion dies can be made to almost any profile, which is why aluminum dominates custom sizing work.
Cast aluminum villa door panels: Molten aluminum is poured into a mold, producing deep relief patterns and thicker sections than extrusion allows. The casting process, pattern tooling, and finishing labor make these panels the most expensive decorative option, but they hold detail well and will not rust.
Steel and wrought iron: Lower material cost, higher long-term cost. Without hot-dip galvanizing plus a multi-coat paint system, rust appears at welds and drainage points within a few seasons.
Timber: Attractive and thermally stable, but it moves with humidity, needs refinishing every 2–3 years in exposed positions, and cannot match aluminum on dimensional accuracy for large spans.

Ask suppliers for the alloy designation and the measured wall thickness of the actual profile they intend to use, not the catalog average.

Structure and Specifications: Where the Money Actually Goes

Once the alloy is fixed, five specification variables drive the remaining cost. Vague answers here are the most common source of change orders.

Specification	Typical Range	Effect on Cost and Performance
Frame profile wall thickness	1.8–3.0 mm	Thicker walls resist wind load and sagging on wide openings; a step up from 2.0 mm to 2.5 mm is a measurable cost jump.
Panel or plate thickness	1.5–3.0 mm sheet	Thin sheet dents under impact; thicker plate adds weight and requires heavier hinges.
Core filling	Aluminum honeycomb, PU foam, rock wool	Aluminum honeycomb filling gives high rigidity at low weight and resists deformation, but costs more than injected foam.
Glazing	5–12 mm tempered or laminated	A glass spliced exterior door design needs laminated or tempered panes, correct gaskets, and drainage channels; double glazing adds thermal performance and weight.
Locking system	Multi-point mechanical to electronic	A smart fingerprint lock requires a reinforced lock box, concealed wiring, and a power route, all of which must be planned before fabrication.

Specify the hinge type and the total door weight early. Hardware rated below the finished leaf weight is the most frequent cause of sagging within the first year.

Key Advantages for Villa Exterior Applications

Aluminum systems earn their place on villa exteriors for reasons that show up over years rather than weeks.

Corrosion resistance: No rust on coastal or high-humidity sites, provided fixings and hinges are also stainless or aluminum.
Low maintenance: A wash with mild detergent twice a year is normally sufficient; powder-coated surfaces do not need annual repainting.
Structural span: Aluminum extrusions carry wide single-leaf gates and tall entries without the bracing ironwork needs.
Dimensional accuracy: Profiles can be cut to millimetre tolerances, which matters when a courtyard opening is out of square.
Integration: Channels for cabling, LED strips, and lock bodies can be designed into the profile rather than added on site.

Custom Options and How Each One Changes the Quote

Options are where budgets drift. Each of the following should be quoted as a separate line so you can compare suppliers fairly.

Finish: Standard powder coating is the baseline. PVDF coating costs more but holds colour better under strong UV. Anodizing offers a metallic look with good abrasion resistance, while wood-grain sublimation adds a timber appearance without the upkeep.
Colour: Standard RAL shades are usually included; custom matching to a facade sample adds a setup charge.
Opening direction: Inward or outward, left or right hand, single or double leaf. Non-standard swings may require a different hinge set or a floor pivot.
Smart fingerprint lock: Adds cost for the unit itself plus the reinforced lock box and wiring provision. Confirm the emergency power method and whether the lock integrates with your building management system.
LED decoration: Low-voltage strips require a driver, a concealed cable path, and a weatherproof junction. Specify the IP rating for exterior use.
Transom lintel: A fixed upper panel or glazed transom raises the total height and needs a heavier frame and anchor schedule.

Buying and Selection Tips Before You Place a Deposit

Measure the structural opening at three points — top, middle, and bottom — and share the smallest figure with the manufacturer.
Ask what is excluded: freight, crane offloading, installation labour, duty, and site welding are commonly left out of factory quotes.
Request a physical finish sample, ideally one that has been through the actual coating line, not a printed colour chip.
Confirm hardware brands for hinges, handles, closers, and the lock body, and check they are rated for the finished leaf weight.
Ask for wind-load and water-tightness test reports if the door faces an exposed elevation.
Clarify the warranty split: surface finish, structural frame, hardware, and electronic components often carry different terms.
Agree on a production and shipping schedule in writing, and align it with your site readiness date.

Conclusion

A custom aluminum courtyard gate or cast aluminum villa door is priced by material grade, profile thickness, infill, glazing, locking, and finish — not by appearance alone. When a supplier can explain each of those variables in measurable terms, you have enough information to judge whether a quotation is competitive or simply cheap. Bring the same specification sheet to every vendor, ask the same questions about exclusions and warranties, and the comparison becomes straightforward rather than a matter of trust.