About Us
Steel Doors Online
Steel Doors Online is a specialist division of Colin’s Sash Windows, created to focus exclusively on made to measure steel doors and steel partition systems for UK homes and commercial interiors.
Built on UK joinery & glazing experience since 2014
Since 2014, Colin’s Sash Windows has supplied bespoke windows and doors across the UK, working with homeowners, builders, architects, and interior designers. That experience sits behind everything we do here, including our technical understanding of internal steel doors, glazing specifications, and FD30 fire rated steel door systems.
Steel doors are often incorrectly specified or poorly explained online. Fire performance, glass types, frame profiles, and installation requirements are frequently overlooked. Our role is to provide clear, accurate guidance before an order is placed — particularly where FD30 fire rated steel doors are required to meet Building Regulations or project specifications.
Correct specification
We confirm measurements, layouts, and frame details before production begins — helping prevent costly mistakes on site.
Compliance & FD30 guidance
Where FD30 fire rated steel doors are required, we guide you through what needs to be confirmed to meet the spec.
Long-term performance
Every steel door is made to order and manufactured to agreed specifications — built for durability, function, and finish.
Why choose us
Why Choose Steel Door Online?
A specialist approach, measured engineering, and a calm buying experience — designed for people who care about details.
Trading since
2014
Backed by an established UK business
Warranty
10 years
Confidence built into every door
Made in
UK
Manufactured in UK factories
Installation
FENSA
Approved installation partners
Specialist internal steel door focus
We focus exclusively on internal steel doors and partitions — a dedicated brand built to deliver precision, not a broad catalogue.
Ultra-slim steel profiles
Architectural sightlines designed to maximise glass and light while maintaining a refined steel structure.
UK manufacturing
Manufactured in UK factories with controlled processes, consistent finishing, and dependable lead times.
Acoustic and laminated glass upgrades
Optional upgrades for better sound reduction and enhanced security — ideal for home offices and busy households.
FENSA-approved installation partners
Supply & fit across the UK through experienced, FENSA-approved installation partners.
Transparent pricing guidance
Clear example pricing and honest specification guidance, so you can make a confident decision without guesswork.
10-year warranty
Every internal steel door is supplied with a 10-year warranty for long-term confidence and peace of mind.
Backed by a company trading since 2014
Steel Door Online is a specialist division supported by an established UK business trading since 2014 — giving you reliable support before, during and after your project.
Our Internal Steel Door
Styles and Configurations
We offer a full range of internal steel door systems, we have enlisted all of them below and to learn more about each simply click
and the detailed information will open.
Single Internal Steel Doors
Ideal for kitchens, studies, hallways, and smaller openings. Single doors can be supplied with or without fixed glazed side panels.
Double Steel Internal Doors (French Style)
Perfect for wider openings and statement transitions between rooms. Double doors can also be combined with fixed side screens.
Internal Steel Sliding Doors
Designed for spaces where swing clearance is limited. Sliding doors can run over fixed panels or be fully recessed.
Pocket Steel Doors
Pocket steel doors slide neatly into the wall cavity, offering the cleanest visual finish while saving space.
Internal Steel French Doors
A symmetrical double-door layout that blends classic proportions with modern steel framing.
Steel Partitions and Room Dividers
Fixed steel screens and partitions divide open-plan spaces without blocking light, commonly used in living areas and offices.
Other Steel Doors System We Offer
As you have seen above with the range of internal steel doors system we also offer the range of external steel doors, FD30 fire rated steel doors and fixed side panels in variety of hardware configurations and colours.
Request a free quote
Share your opening sizes and preferred configurations. We'll respond with a tailored quote.
By submitting, you agree we can contact you about your enquiry. We never sell your details.
Contact Details
Prefer to speak to our specialists? We're happy to help
CALL
01525 552131
Website
steeldooronline.co.uk
* Some postcode exclusion apply and are confirmed at quotation stage.