Buying new windows and doors is a significant investment in your home. It’s natural to explore multiple options before deciding, but how do you ensure you compare like-for-like quotes? Beyond the overall price, the devil is in the details and understanding what you’re paying for is key to making the best choice. We’ve created this guide to help you evaluate different quotes when buying premium timber windows and doors so you can select the perfect combination of quality, service, and value for your needs.
When comparing quotes, the critical differences come down to thermal efficiency, acoustic insulation, durability, security and compliancy. Sashed provides independently tested, whole-window performance values to give full transparency.
Carefully examine the specifications provided in each quote. Here are the critical elements to consider:
Thermal & Acoustic Performance
Our double glazed sash and casement windows have a U-Value of 1.2 W/m²K (whole-window Uw).
Our double glazed door-sets have a U-Value of 1.3 W/m²K (whole-window Uw).
The above U-Values are determined using industry-standard testing parameters and dimensions, and are independently verified by a UKAS-accredited test laboratory, accreditation number 23361.
Our vacuum glazed door-sets windows have a U-Value of 0.76 W/m²K (whole-window Uw).
Our vacuum glazed sash and casement windows have a U-Value of 0.76 W/m²K (whole-window Uw).
The above U-Values are determined using industry-standard testing parameters and dimensions, and are calculated with Klaes software, a market-leading ERP solution specifically designed for the fenestration industry.
Acoustic insulation: Standard double glazing achieves up to 31 dB, Vacuum glazing achieves up to 39 dB, our Silver acoustic double glazing up to 40 dB, and our Gold acoustic double glazing up to 42 dB.
Gaskets and Seals
Gaskets and seals are critical for weatherproofing. We use market-leading Q-Lon gaskets and a bed of specialist silicone between the glass and timber to create a moisture barrier, preventing condensation from damaging the wood.
As an example we have integrated 17 individual innovative gaskets and seals into our most popular sash window profile, which is one of the reasons why we achieve market-leading low whole-window U-Values for timber windows.
The finish
The painted or stained finish significantly impacts the lifespan of your windows. At Sashed, we apply four coats of microporous paint or stain using advanced spray technology, creating a beautiful, durable layer that protects the wood from the elements for years. Hand-painted finishes, by contrast, deteriorate much faster.
Durability & Warranties
The quality of the wood is paramount to the durability of your windows and doors. All Sashed timbers are high grade, dehumidified timbers that undergo meticulous drying and treatment to prevent warping or movement once installed.
100% Accoya timber used throughout our Accoya windows – unlike many competitors who only use part Accoya.
Timber warranties: Pine 20 years, Larch 25 years, Meranti & Oak 30 years, Accoya 50 years.
Paint system: Teknos microporous – Pine/Larch/Meranti/Oak 10-year warranty, Accoya 12-year warranty.
Glazing warranties: Double glazing 10 years, vacuum glazing 15 years.
Discreet profiles
Our double glazed and vacuum glazed sash windows feature 35mm meeting rails, which conservation officers prefer for their refined proportions. Thicker rails can look bulky and detract from the classic aesthetic of your windows.
Most of our products now come with our unique, discreet trickle vents, which are hidden within the frame internally for a beautifully minimalist look. From the outside, they are completely invisible
Security & Compliance
Multi-point locking as standard on all windows and doors, internally beaded glazing for enhanced security.
FENSA registered – certificate provided after completion.
TrustMark certified – UK Government-endorsed tradespeople.
RIBA CPD Provider – authorised by the Royal Institute of British Architects (RIBA) to deliver Continuing Professional Development (CPD) activities for architects and design professionals.
If you have chosen Sashed to install your new windows and doors, we will ensure that your products comply with the relevant building regulations, where applicable:
- Approved Document A – Structure (eg. Casement bay windows).
- Approved Document B – Fire safety and escape routes.
- Approved Document C – Site preparation and resistance to contaminants and moisture.
- Approved Document F – Ventilation.
- Approved Document J – Combustion appliances and fuel storage systems.
- Approved Document K – Protection from falling, collision and impact.
- Approved Document L – Energy efficiency standards.
- Approved Document M – Access to and use of buildings.
- A range of products certified to PAS 24:2022 and Part Q building regulations are available upon request.
Sustainability
We only use PEFC certified timbers and low-VOC water-based paints.
Zero-waste production; all offcuts recycled or used to produce heat for production facilities.
Zero to landfill policy; any old windows or doors we remove are fully recycled.
One tree planted per window or door through Ecologi partnership (see the this page for more details)
Beyond the products: Evaluating the company and service
The company you choose is just as important as the windows themselves. Here’s what to look for:
1. FENSA certification
Ensure the company is FENSA registered. This guarantees compliance with building regulations and provides peace of mind that the installation meets industry standards. Our FENSA details are available here.
2. Insurance-backed guarantees
Check the warranty policy. Sashed provides an insurance-backed guarantee for all products installed by us in non-commercial buildings, fully supported by the Independent Warranty Association (IWA).
3. Installation services
Installation quality varies widely. Our expert installers are employed by Sashed, we don’t sub contract our installations. Many companies use filler and mastic for external finishing, but Sashed’s premium installation service includes:
- Mortar pointing externally around frames.
- Patch plastering for internal walls.
- Sanding surfaces for a flawless, paint-ready finish.
4. Ethical practices
Be cautious of companies offering cash discounts, as they may not declare the full contract value to FENSA or guarantee providers. This could leave you unprotected if issues arise. A reputable company will always operate transparently.
5. Independent endorsements
Sashed is a vetted and endorsed Which? Trusted Trader, a distinction that reflects our unrivalled commitment to quality and customer satisfaction. Unlike some industry schemes, Which? works for the consumer, ensuring rigorous vetting and providing an independent dispute resolution service if needed.
6. Trust and reputation
Do you feel confident in the company’s advice and expertise? Are they responsive and proactive in addressing your questions? Positive reviews and a history of successful projects are excellent indicators of a company you can trust.
We are consistently reviewed with 5 stars (excellent) by our customers.
Why choose Sashed?
At Sashed, we pride ourselves on delivering exceptional products paired with outstanding service. Our design led joinery approach ensures that every window and door we craft is tailored to your unique needs. We understand that your home is unique, and we provide the following to create windows and doors that reflect its individuality, combining timeless beauty and modern innovation.
In Summary
While Sashed quotes may sometimes look higher at first glance, they reflect independently tested performance, superior materials & build quality, longer warranties, certified compliance and higher thermal standards, which are factors often omitted from cheaper comparisons.
If you have questions or need further advice, our team would love to hear from you. Call us on 020 3198 4472 or contact us online.