Having so much to choose from can make buying new windows a difficult undertaking. Have a read of our most frequently asked questions to simplify the process.
How do flush and casement windows differ?

If you didn’t know, the casement refers to the moving part of the window – the bit that opens and closed. In a standard (or ‘lipped’) window, the casement sits proud of the surrounding frame.

A flush casement window has a casement that sits exactly level with the window frame, which for some, gives it a smarter and more underplayed appearance. The easiest way to spot the difference between the two is to visit our Lincoln showroom, where we have both products on display.

Oak Envisage Flush Windows
Shall I buy Double Glazed or Triple Glazed Windows?

The obvious difference between double and triple glazing is the panes of glass within the unit – double glazed has two and triple, as you would expect, has three.  There are pros and cons to be considered with both options, and we’d recommend speaking to a James Oliver advisor to determine which is the most suitable option for you.

The biggest and most obvious difference between a double and triple glazed window is that the latter product has an additional glass pane – three as opposed to two. Both options have their merits and will benefit your home in different ways. Talk to a James Oliver to discuss this in more detail.
You will find though that a triple glazed window is particularly good for heat retention and eliminating draughts. So long as it is correctly specified, it can also reduce the impact of external noise, which will be music to your ears if you are regularly disturbed by noise from a busy nearby road or train line.

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Get any questions off your chest and direct them to one of our friendly and knowledgeable advisors. Some of the questions they often get are answered below.

Is there any between PVC Windows, PVCu Windows & UPVC Windows?

They’re all the same product and to clarify, they should be referred to a PVC-U windows, nothing else.

It was in the late 1980’s that UPVC was changed to PVCU in the UK to bring it in line with other European countries. It seems that they were all calling it call it PVC-U because European languages mostly place the noun (being PVC in this case) before the adjective (U).

Most people don’t know that ‘PVC’ stands for Poly Vinyl Chloride. The ‘U’ bit stands for Un-plasticised. Poly Vinyl Chloride, often abbreviated as ‘PVC’, is modified for use in the manufacturing of products like bags, shoes, and fake leather. Therefore, most people are familiar with the abbreviation ‘PVC’.

It isn’t possible to use pure PVC-U for making replacement windows as it needs a few additives to ensure any windows are weatherproof, offer the right amount of UV resistance and will last. They’re also needed to create that classic white colour you find on most windows and doors.

What coloured finishes are available?

White is just one of many colours you can have. Our replacement windows and doors are available in a host of striking finishes, with something for everyone.

Some customers will be perfectly happy with white or cream windows, but if you want a different colour, how about Anthracite Grey, Hazy Grey or Olive Grey windows as a break from the norm?

We’re also pleased to offer you several woodgrains, such as Rosewood, which has a rich darkness, and bold oak effect colours. For a statement colour, look no further than Chartwell Green, Dark Red and Steel Blue.

You can combine colours if you find yourself torn over two finishes, with one colour on the outside and one colour on the inside.

Can you explain what an 'A' rated window means?

To help you identify the energy efficiency of a window, Window Energy Ratings (WERs) are used, very similar to a traffic light system. You can find energy ratings on most white goods, such as fridges, freezers, washing machines, and the energy ratings for windows work in a very similar way.

An A+ rated window is the most energy efficient window you can get in this country, as defined by the BFRC Rating Scheme, the UK’s national system for rating the energy efficiency of windows. A+ rated windows easily comply with the standard of thermal efficiency required to satisfy Building Regulations.

Keep your eyes peeled for windows with an A or A+ rating as they will give you the most warmth and energy efficiency.

It is a legal requirement that new, or replacement windows must have a minimum WER of C or above. Speak to a James Oliver advisor about Window Energy Ratings.

What does U-Value mean?

A U-Value tells you how good a window is at retaining internal heat and stopping it from escaping. U-Values are measure in Watts per square metre, or W/m2 K. The lower the U-Value number, the better the heat retention of the window.

The minimum permitted U-Value of a new or replacement window is 1.6 W/m2 K. For more information about U-Values, just ask an advisor for guidance.

What is Secured by Design?

Secured by Design (SBD) is a Police-run initiative that’s all about enhancing the security of buildings and making them safer places to be.

The Police Preferred Specification, SBD’s product-based accreditation scheme, is the recognised standard for products that are secure enough to discourage and minimise crime. This includes domestic windows and doors, and the components within them such as locks, hinges etc.

Conservatory Outlet, which is our sister manufacturing company, is a registered member of Secured by Design, so we can tell you that most of our products have been tested to meet the necessary standard. If window security is a particular concern, inform one of our advisors of this.

Do you make your own windows?

We certainly do. James Oliver is one of several installers in the Conservatory Outlet Group of companies and its sister company, Conservatory Outlet, is one of the country’s leading manufacturers of UPVC and aluminium windows. Our entire window range is built at Conservatory Outlet’s hi-tech manufacturing facility in Wakefield, West Yorkshire.

The advantage of having such a tight relationship with our manufacturer is that we can retain close control over supply chain, making sure that our product quality is always sustained.

Is James Oliver a member of FENSA?

Yes, James Oliver has been a FENSA (Fenestration Self-Assessment Scheme) member for several year now. Setup by the Glass and Glazing Federation (GGF) and various other industry bodies, the scheme is Government approved, with all its members working in line with current Building Regulations.

Thermal performance standards must be adhered to when getting new replacement windows and doors installed and you also need to receive a certificate of compliance from FENSA or Local Authority Building Control.

FENSA also allows its member companies to self-certify compliance when installing replacement windows and doors.

How much will new windows and doors cost?

We would really need to speak with you first and get an understanding of your home before we could give you an estimate of the cost involved.

Our windows and doors are tailored for each customer as homes have different openings and require different fittings. You also need to be aware that there are many style and colour options at James Oliver, so until we know exactly what you want, it is hard to provide a costing. Let’s talk and give you a price that way.

Get a free design consultation organised, which can either be held at your home or in our showroom or make an online appointment and we can discuss your requirements virtually, via Zoom.

Just submit your details in our Appointment Booking Form to get this arranged at a time and date that suits you.

How long does an appointment take?

Usually, it will last for a minimum of one hour as the James Oliver designer needs at least this amount of time to understand what you want and provide solutions that fit with your requirements.

How long will it take to install my new windows and doors?

That will depend on the type of job involved. For instance, it could require the installation of many windows and doors, and some installation projects are more complex than others. To give you a rough estimate, it normally takes around 3-4 days to install a full house of windows and doors. You will be given a more precise estimate by your James Oliver advisor.

Can I get finance for new windows and doors?

Yes, you can. James Oliver has a series of affordable and convenient payment finance options (subject to application & status). Making a finance application is really easy and you won’t be kept waiting long for a decision. You can sort the application at our Lincoln showroom, or if it’s more convenient, we’re more than happy to come out to your home with the necessary paperwork.

What do I do when my finance is approved?

If you are organising finance yourself, just get in touch as soon as it has been approved. When finance is being arranged via James Oliver, the finance company will notify us of approval, so we will let you know.

What happens if I’m refused for finance?

There are any number of reasons why someone might be refused finance. Sometimes it’s because someone has moved several times in recent years. Whatever the reason, we will try to help as best we can. It could be worth trying a provider who knows you.

How long does it take to receive approval?

You may well find out pretty much straight away or it could take a few days for confirmation to be given. Any delay isn’t something to be concerned about as it could be down to several things.


With over 40 years of experience in transforming properties across Lincolnshire and the East Midlands, we’re proud to be the region’s most trusted home improvements firm.

No Pressure Sales

Our sales teamed are trained and motivated to be not only fully transparent, but to make our customers at ease with the options available to them. They won’t stay any longer than they need to and won’t force you into decisions that you’re not comfortable with - guaranteed.

Designed For You

A really important ethos of our business is to make the customer feel comfortable with their home improvement decisions. Our experts are there to help you make great decisions from all the options available to you, whether that be shape, style, colour, material or finishes.

10 Year Guarantee

James Oliver 10 Year Guarantee offers you complete value for money and, crucially total peace of mind that your product are covered by our comprehensive guarantee. Our confidence in our products and dedication to our customers means we’ll be there for you well into the future.

Exclusive Products

By choosing James Oliver to oversee your home improvement project, you’ll benefit from our exclusive – and not to mention market-leading – range of products. You’ll quickly discover why James Oliver offer Lincolnshire and the East Midlands’ premier range of products.


See how affordable your home improvement can be with our Finance Calculator.
  • BUY NOW PAY MONTHLY 12.4% APR Representative Spread the cost of your home improvements over 60, 120 or 154 months*
  • BUY NOW PAY IN 3 MONTHS 11.9% APR Represenative Order today and pay nothing for 3 months.
60 monthly payments
Representative APR
120 monthly payments
Representative APR
154 monthly payments
Representative APR
This finance option allows you the convenience and flexibility of spreading the cost of your home improvements over 60, 120 or 154 months*. You must make the minimum repayment each month. However you can also make additional payments and therefore control the length of the loan and the amount of interest you would pay. No security is required on these loans. These calculators are for illustrative purposes only and do not constitute a credit quotation. *120 & 154 months finance only available for orders over £8,000.

Representative Example

Cash Price
Total Amount of Credit
Duration of Agreement
60 Months
Rate of Interest
12.4% p.a. fixed
Representative APR
12.4% APR
60 Monthly Payments
Total Amount Payable
Pay within 3 months + £29 exit fee
Want to pay in monthly instalments after 3 months rather than one-off payment? Consider this option.
120 monthly payments
Representative APR over 10 years
This option allows you a 3 month payment holiday from the date of completion. Pay 10% deposit when you order, and as long as you pay the outstanding balance in full before 3 months has elapsed plus a £29 settlement fee, no interest will be charged. If, after 3 months, this is not convenient, you can pay in 120 monthly installments at 11.9% APR Representative. *Deferred for 3 months from the date of completion – £29 settlement fee applies if the loan is repaid in full during the deferral period and NO INTEREST will be paid. For legal reasons the Representative Example shows interest IF the outstanding balance is NOT paid before the 3 months has elapsed. No security is required on this loan. These calculators are for illustrative purposes only and do not constitute a credit quotation. For legal reasons the Representative Example shows interest IF the outstanding balance is NOT paid before the 3 months has elapsed. No security is required on this loan. These calculators are for illustrative purposes only and do not constitute a credit quotation.

Representative Example

Cash Price
Total Amount of Credit
Defer By
3 Months
Duration of Agreement
123 Months*
Rate of Interest
11.9% p.a. fixed
Representative APR
11.9% APR
120 Monthly Payments
Total Amount Payable
Settlement Fee


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