A homeowner's dispute involving a national window supplier concluded with a £20,000 refund after technical evidence was assembled to support the claim.
Independent Technical Consultancy
When a window or door project has gone wrong — you need evidence, not opinions.
DMR Consultancy provides independent technical inspections, reviews and reports for defective, mis-sold or poorly installed windows and doors. Not free advice. Not sales patter. Evidence, clarity and leverage.
100%
Independent — no trade ties
10+ years
Specialist industry experience
1 focus
Windows and doors only
Not another window company. An independent consultancy working exclusively for you — not the trade.
The Problem
Window and door disputes are common. Good technical evidence is rare.
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Defective installation Poor fitting, failed seals, water ingress, misaligned frames — the installer says it's fine. You know it isn't.
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Mis-sold products Promised energy ratings, security specs, or acoustic performance that the units don't deliver.
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Poor specification Wrong products chosen for the application — planning constraints, heritage settings, or thermal performance ignored.
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No independent voice Every party — manufacturer, installer, retailer — has an interest in minimising your claim. You have nobody on your side.
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Disputes without evidence Courts, ombudsman schemes and solicitors need documented technical evidence — not a strongly worded email.
"The product is evidence, clarity and leverage — not free advice."
Window and door companies have every incentive to deny, delay and deflect. DMR Consultancy exists to give individuals, solicitors and claims professionals the technical weight to cut through that.
Our reports are prepared by an independent consultant with no commercial relationship with any manufacturer, installer or trade body. That independence is the product.
Services
What DMR Consultancy does
Technical Site Inspections
On-site examination of installed windows and doors against specification, building regulations, and industry standards. Documented findings with photographs and measurements.
Independent Expert Reports
Formal written reports suitable for use in legal proceedings, ombudsman complaints, insurance claims, and civil disputes. Clearly structured and technically evidenced.
Specification Review
Review of window and door specifications prior to or following installation — identifying product suitability, planning compliance, thermal performance, and specification accuracy.
Defect Investigation
Systematic assessment of reported defects including water ingress, condensation, thermal failure, operational faults, glazing defects, and structural inadequacy.
Dispute & Claims Support
Technical support throughout the dispute process — from initial complaint correspondence through to ombudsman referral, mediation, or court proceedings.
Solicitor & Legal Support
Expert witness and technical advisory services for legal teams handling fenestration disputes, consumer claims, contractor negligence, and construction defect litigation.
Planning & Heritage Assessments
Technical assessment of window and door choices in planning-sensitive or heritage contexts — supporting applications, objections, or retrospective compliance queries.
Mis-Selling Assessments
Technical evaluation of whether products delivered match those specified, quoted and contracted — supporting consumer rights claims and Trading Standards referrals.
Pre-Purchase & Snagging Reviews
Independent assessment of windows and doors as part of a property purchase or new build snagging process — identifying defects before completion.
How It Works
Simple, clear and on your side
From first contact to final report — a straightforward process designed to give you technical clarity as quickly as possible.
1
Initial Enquiry
Contact us with a brief description of your situation. No obligation. We'll confirm whether we can help and what approach is appropriate.
2
Scope & Instruction
We agree the scope of inspection or review required, confirm fees, and issue a formal letter of instruction so you know exactly what you're getting.
3
Inspection or Review
Site inspection, document review, or specification analysis — carried out independently with detailed technical notes, photographs and measurements.
4
Report Delivered
A clear, structured written report documenting findings, technical assessment, and conclusions — ready for use in correspondence, complaints or legal proceedings.
Who We Help
Anyone who needs independent technical weight on their side
Homeowners
You've spent thousands on windows or doors that are defective, mis-sold, or poorly installed. The installer won't engage. You need documented evidence to make your claim stick.
Solicitors & Legal Teams
You need technically credible reporting that translates complex fenestration issues into clear evidence for correspondence, negotiation or legal proceedings.
Property Managers & Landlords
Defective installations in rented properties, service charge disputes, or contractor accountability — DMR provides the independent technical assessment you need.
Surveyors & Consultants
Where specialist fenestration knowledge is required beyond a general building survey — expert input on specification, defect causation, or dispute matters.
Developers & Project Managers
Pre-handover snagging, contractor performance disputes, or specification compliance — independent assessment before or after practical completion.
Housing Associations & Local Authorities
Large-scale procurement disputes, contractor performance, or resident complaints about window and door installations across housing stock.
About DMR Consultancy
Independence is the product
No trade relationships
DMR Consultancy has no commercial relationships with any window manufacturer, installer, or trade body. Our findings cannot be influenced by the industry we assess.
Technical depth, not sales patter
We understand building regulations, British Standards, energy performance requirements, glazing specifications, and installation standards — in detail.
Reports that stand up
Our reports are written to be used — in ombudsman complaints, legal proceedings, insurance claims, and negotiation. Clearly structured, evidenced and professionally presented.
One specialisation only
We focus exclusively on windows and doors. Not general building surveys, not roofing, not drainage. That focus means deeper expertise and sharper reports.
Honest about what we find
If the installation is actually acceptable, we'll tell you. We don't manufacture grievances — but where problems exist, we document them completely and accurately.
Not advice. Not opinions. Technical evidence.
The window and door industry is heavily weighted against the customer. Manufacturers, installers and retailers all have legal teams, trade bodies, and standard deflection scripts.
The only thing that cuts through that is documented technical evidence, prepared independently, by someone who knows what the standards require and what the installation failed to deliver.
DMR is led by Dalan Rustemoglu, a window and door specialist with more than 10 years of hands-on experience across surveying, specification, installation review and project management.
That is what DMR Consultancy provides.
Evidence, clarity and leverage.
Evidence in Practice
A verified anonymised case outcome
We publish only outcomes that can be stated accurately without identifying the client.
Every matter depends on its own evidence, contract and circumstances. A previous outcome does not guarantee the result of another case.
Frequently Asked Questions
What clients usually want to know first
Clear answers before you decide whether to instruct us.
How much does an inspection or technical report cost?
Fees depend on the property, the number of windows or doors, the documents available and the level of reporting required. We confirm the scope and fee before any work begins.
Do you work for window manufacturers or installers?
No. DMR Consultancy is independent and has no commercial relationship with a window manufacturer, installer or trade body.
Can your report support a complaint or legal claim?
Reports can be prepared for complaint correspondence, ombudsman referrals, insurance claims, mediation or legal review. We agree the appropriate format and scope before instruction, and no particular outcome can be guaranteed.
Which areas do you cover?
Document and specification reviews are available nationwide. Site inspections are available across England and Wales, subject to location and scope.
What should I provide with my enquiry?
Start with a short description of the problem. If available, keep your quotation, contract, specification, photographs, guarantees and correspondence ready for review.
How quickly will you respond?
We aim to respond to initial enquiries within one working day. Inspection availability and report timescales are confirmed after we understand the scope.
Get in Touch
Tell us about your situation
No obligation. We'll review your enquiry and confirm whether we can help, and what type of inspection or report is appropriate.
What Happens Next
We review every enquiry personally and respond within one working day. We'll confirm whether your situation falls within our scope and outline the appropriate service and fee.
Areas Covered
Nationwide coverage for report and document reviews. Site inspections available across England and Wales — contact us to confirm your location.
No sales calls. No upselling. If we can help you, we'll tell you clearly what that looks like and what it costs. If we can't, we'll say so and point you in the right direction.