Preserving Character.Improving Performance.
Specialist timber window restoration, repair, draught proofing and new installation — delivered across London and the UK by CHAS accredited, DBS checked professionals.
Preserve what matters. Improve what’s possible. Deliver what lasts.
Velziyn Projects is a specialist timber window contractor delivering restoration, repair, draught proofing and new window installation across London and the United Kingdom. We work across residential, commercial, and educational properties — always with the care and professionalism that the job demands.
From period sash windows in listed buildings to modern timber frame replacements, our CHAS accredited and DBS checked team approaches every project with technical knowledge, genuine craftsmanship, and respect for the property.
What We Do
Featured Projects
Where We Work
From listed residential homes to commercial buildings, schools and civic estates — we are set up to deliver professionally across all sectors.
Listed Residential
Private and landed estate residences under Grade I, Grade II*, or Grade II protection requiring fabric-first conservation and delicate traditional joinery repair.
Learn MoreConservation Areas
Period residential streets and designated urban conservation zones where external visual continuity, sightlines, and proportions must be strictly maintained.
Learn MoreHistoric Public Buildings
Town halls, historic libraries, assembly rooms, and community assets demanding robust operational longevity, acoustic comfort, and compliance.
Learn MoreMuseums & Cultural Institutions
Galleries and historic collections where environmental stability, UV filtration, and acoustic insulation are critical to protecting interior artefacts.
Learn MoreProven Products & Methods
We use independently certified, industry-leading systems specifically designed for durable timber window restoration and conservation.
Repair Care & DRY FLEX® Resin System
A unique flexible resin system allowing durable, elastic timber repairs to cills, frames and mouldings. Retains original timber, reduces waste, and is fully compatible with heritage conservation requirements.
- Permanent elastic bond - moves with surrounding timber
- Cost-effective alternative to full replacement
- Approved for use on Grade I & II Listed structures
Draftfix Perimeter Draught Exclusion
High-performance weather pile with a central fin rebated discreetly into parting beads, staff beads and meeting rails. Independently tested for air tightness and water permeability — zero visual alteration to the window appearance.
- Eliminates perimeter draughts and sash rattle
- Substantially reduces operational heating costs
- Zero visual alteration to exterior or interior sightlines
Our 6-Stage Process
From initial consultation and site survey through to final sign-off and handover documentation.
Initial Consultation
A detailed client discovery conversation to understand project scope, heritage constraints, specification requirements and programme.
Condition Survey
A non-invasive technical inspection of existing window stock using professional defect logging and conservation assessment.
Specification & Quotation
A precise, itemised scope of works and quotation developed in line with survey findings, CAD section drawings and client requirements.
Consent & Compliance
Close liaison with conservation officers, local planning authorities and architects to secure Listed Building and Conservation approvals.
Controlled Delivery
Phased, supervised on-site delivery using CSCS-certified operatives, RAMS-controlled methodology and structured project management.
Final Inspection & Sign-off
Formal sign-off inspection against specification, defects resolution, handover documentation, guarantees and aftercare guidance.
Set Up to Work with Main Contractors & Commercial Clients
Velziyn Projects maintains the accreditations, documentation and health & safety management that professional clients, main contractors and schools require.
Our operatives are Enhanced DBS checked — particularly important for the school and sensitive-site projects we regularly deliver.
View Full CredentialsCHAS Accredited
Demonstrated compliance with standard health and safety criteria through accredited contractor assessment.
Constructionline
Formal pre-qualification assessment underway. Current status: Application / Approval Pending.
BrightHR / BrightSafe
Comprehensive workplace Health & Safety management, competent advice support, and continuous compliance oversight.
Enhanced DBS Checked Operatives
Enhanced Disclosure and Barring Service vetting completed for operational delivery across educational, civic, and sensitive residential environments.
CSCS Competent Operatives
Site operatives hold verified Construction Skills Certification Scheme qualifications appropriate to specialist heritage joinery works.
RAMS & Strict Policies
Comprehensive site-specific Risk Assessments & Method Statements produced for every stage of restoration, scaffolding, and installation delivery.
Ready to Restore, Repair or Replace Your Windows?
Whether you have a single window or a large programme of works, our team will provide a professional, detailed response to your enquiry.