Rear extension bifolds
Opening alignment, suitable supports and floor-level details before bifold fitting.
DF INSTALLATIONS · HATFIELD · HERTFORDSHIRE · NORTH LONDON
Glazing installation for house extension builders
Window, door, bifold, sliding patio door and roof lantern fitting for builders specialising in kitchen extensions, rear additions and residential remodelling across Hertfordshire and North London.
20+ years' fitting experienceWindows · Doors · Roof glazingSupply & fit / installation onlyHertfordshire · North London
WHO WE WORK WITH · Extension specialists & kitchen-extension builders
The finishing touch to an extension.
Window, door, bifold, sliding patio door and roof lantern fitting for builders specialising in kitchen extensions, rear additions and residential remodelling across Hertfordshire and North London.
Discuss supply responsibility, programme, site readiness, product specifications and access before a project is confirmed.
SPECIALIST TRADE SERVICES
Installation support for real projects.
The right service depends on your system, site and agreed responsibilities. Here are the installation packages we can discuss.
Sliding patio doors
Wide openings, threshold positioning and drainage coordination.
Roof lanterns
Glazing into correctly detailed roof upstands with clear roof weathering responsibilities.
Kitchen extension windows
Casements, fixed lights, feature glazing and specialist window designs.
French and rear doors
Double-leaf door access and practical threshold solutions.
Installation-only packages
Fit approved systems supplied by the main contractor when scope and specification are agreed.
WHY WORK WITH DF?
Built around trade priorities.
One point for glazing installation
Discuss bifolds, windows and rooflights under a coordinated fitting scope.
Less programme disruption
Check opening readiness, finishes and delivery sequence before booking.
Threshold detailing
Review proposed floor buildup and water management around wide glazed openings.
Practical handover
Adjust opening systems, check operation and agree finishing responsibilities.
PRACTICAL PROJECT PLANNING
Extension glazing should be planned before the plaster goes on.
On extensions, the critical details include lintels and structural support, opening dimensions, thresholds, internal and external levels, weatherproofing and lifting access. We coordinate installation with the builder's programme but do not replace structural engineers or Building Control.
Send the details
Tell us the project address, intended systems and what needs installing.
Review the specification
Share drawings, unit schedules, manufacturer details and access requirements.
Agree scope & timing
Confirm supply, lifting, installation interfaces, finishing, programme and compliance responsibilities.
Fit & hand over
Carry out agreed work, check operation and discuss any outstanding items.
RELATED DF SERVICES
Explore products and installation services.
Detailed information about the windows, doors and roof glazing we can discuss, plus our existing trade-relevant services.
LOCAL COVERAGE
Trade installation in Hertfordshire & North London.
Based in Hatfield, we welcome suitable commercial and subcontract installation enquiries across Hertfordshire, selected parts of North London and nearby Bedfordshire. Share the project postcode to confirm travel and availability.
TRADE QUESTIONS
Frequently asked questions.
A few practical details to settle before appointing a glazing subcontractor.
Can you install bifolds and a roof lantern on the same extension?
We can discuss both as a coordinated glazing package, subject to specification, access and scheduling.
When should a builder book an installer?
As soon as opening sizes, intended systems and lead times are known. Confirm the final date after structural works and readiness checks.
Who handles drainage around a sliding door threshold?
Responsibility must be agreed between installer and builder, including external paving levels and water management.
Do you fit contractor-supplied glazing?
Suitable installation-only packages can be reviewed with full manufacturer details and a clear scope.
What areas do you cover?
DF Installations is Hatfield based and considers projects across Hertfordshire, parts of North London and nearby Bedfordshire, subject to location, capacity and scope.
How do we request a trade quotation?
Use the enquiry page to share your company details, site postcode, drawings, planned timescales, product specification and the work you need completed.
WORK WITH DF INSTALLATIONS
Let's discuss your next project.
Tell us about your company, the site location, your products and your installation schedule. We can discuss whether the work is a good fit.
Request a trade quotation ↗