Slimline uPVC Windows

The thinnest uPVC windows in the UK. 12% more glass, A+ rated, and the same price as a standard uPVC window.

Designed, supplied and fitted by our own team across Surrey, Berkshire, North Hampshire, Middlesex and West Sussex. Showroom in Guildford.

Slim frames used to mean aluminium, and an aluminium price. We designed Slimline to change that.

The frame is thinner than any other uPVC window on the market, so you get 12% more glass in the same opening, and it is the only window in our range rated A+.

From £1,249 per window, supplied and fitted, including VAT.*

White uPVC mock sash windows with astragal bar fitted to a house front in Surrey

From £1,249 per window*

Based on a 1800 x 1200mm window in white, fitted, inc VAT, based on 4 windows fitted.

A+ rated

The only A+ window in our range, with a 1.2 whole window U-value

PAS 24 available

Enhanced security, specified on any window

Quote in 4 working days

Home visit in 2, written quote 2 after that

8 to 10 weeks

Order to installation, then 1 to 2 days on site

10 year guarantee

Insurance backed as standard, plus your FENSA certificate

What Slimline windows cost

From £1,249 per window, supplied and fitted, including VAT.* Four windows on that basis are £4,996.

Most window companies will not put a number on a page. We will, because you need one before you invite anyone into your house.

Prices are indicative. Access, the condition of the existing frames and the fitting itself all move the final figure. Your quotation is the accurate number, and it is free.

Colours and woodgrain finishes cost more.

Spread the cost

Your payment can be spread monthly over a term of up to 10 years.** Finance is provided by Dopple and you apply through our finance portal. A small deposit is due on order, the balance on completion.

1930s semi-detached house with prominent two-storey white bay window, with new uPVC Slimline windows, energy-efficient replacement complete

How long it takes

Stage How long
Enquiry to home visit As little as 2 working days
Home visit to quotation 2 working days, up to 5 for specialist items
Order to technical survey Up to 10 working days
Order to installation Generally 8 to 10 weeks
Time on site Typically 1 to 2 days for a full house
Do you need to move out? No. You stay in the house throughout

You get a fitting date when you order, not a window of weeks. If a delivery slips, we call you before you have to call us.

Why quotes are valid for 14 days

Glass manufacturing is heavily energy dependent, so our costs move with energy prices. Rather than pad every quotation against a rise that may not happen, we quote the real number on the day. If it lapses, come back whenever you are ready and we will requote free of charge.

Fitters Installing Black uPVC Slimline windows

Why homeowners choose Slimline

You want more light. A thinner frame means a bigger pane in the same opening. Across a run of windows on the front of a house, the difference is easy to see.

You want the aluminium look without the aluminium price. Slim sightlines used to be an aluminium only feature.

You do not want to trade performance for looks. The outer wall is 3mm against a 2.8mm industry standard. The frame is thinner and stronger, not thinner and weaker.

You want the whole house to match. Slimline is designed alongside the rest of our range, so a new front door will match your new windows.

Frame

The thinnest uPVC on the UK market

Colours

34 finishes, including 8 woodgrains

Security

Trojan multi-point shootbolt locking, tested to BS7950

Opens to

90 degrees, meeting British Standards and FENSA requirements

Custom Handles

12% more than a standard uPVC window

Slimline window security

A slim frame does not mean a compromise on security. Every Slimline window can be specified to PAS 24, the enhanced standard Building Regulations require on new homes, which means it has been physically attacked under test conditions and held.

  • Trojan multi point shootbolt locking, tested to BS7950
  • Security glazing as standard, so the unit cannot be removed from outside
  • Hinge protection against jemmying
  • Reinforced frames and internal beading
  • Laminated security glass available

Tell your surveyor if security is a priority and we will specify accordingly.

Rosewood Slimline uPVC Double Glazed Windows

Expertise You Can Trust

Proudly serving Surrey since 1972, we’re a family-run glazing company offering quality windows, doors, conservatories, and bespoke glass solutions. Whether you’re upgrading your home’s look with double glazing, choosing a new front door, or planning a unique orangery, our team is here to bring your vision to life.

Slimline, standard uPVC or aluminium?

Three things usually decide it: how slim you want the frame, how much you want to spend, and how much upkeep you are willing to do.

Slimline uPVC Standard uPVC Aluminium
From, per window £1,249 £1,249 £2,099
Energy rating A+ A A
U-value 1.2 Ask your surveyor 1.3 to 1.4
Frame depth 63mm 70mm Ask your surveyor
Glass area 12% more Baseline Most
Largest openers 700 x 1500mm Larger Largest
Flush casement No Yes Yes

Slimline wins on glass area and rating at the same price as standard uPVC. Standard uPVC wins on larger openers and flush sashes. Aluminium takes the biggest spans, though it is not the warmer option.

Not sure? Bring a photo of your elevation to the Guildford showroom.

Planning your next project? Check if we cover your area.

Sheerwater Glass proudly provides window and door installations, repairs, and glazing services throughout Surrey and the surrounding areas from our showrooms in Guildford and Woking.

To find out whether we cover your area, simply click the button below and check your postcode.

Check your postcode

Styles and configurations

Side hung, top hung and fixed lights in any combination. Bay and bow windows. Arched and shaped heads. Georgian and leaded designs. A cat flap fitted into the glass. Trickle vents where Building Regulations require them.

Slimline is not available as a flush casement. If you want a sash that sits flush within the frame, our flush casement range does that in uPVC, timber and aluminium.

Colour Options

Slimline specification

Window Energy Rating A+
U-value 1.2 W/(m2K) whole window. Upgradable to 1.0
Sealed unit 28mm minimum, argon filled, low emissivity coated, warm edge spacer bar
Frame depth 63mm minimum
Sightline 128mm
Outer wall thickness 3mm, against a 2.8mm Class A industry standard
Maximum sash, side hung 700 x 1500mm
Maximum sash, top hung 1200 x 1200mm
Opening angle 90 degrees
Security Can be specified to PAS 24. Trojan shootbolt locking to BS7950
Reinforcement Reinforced frames as standard
Colours and finishes 34, including 8 woodgrains

Hear from our customers

“Nick from Sheerwater Glass just finished fitting my windows – Great service, quick, efficient and very friendly. Definitely recommend.”

Deborah Proudfoot
Sheerwater Glass Customer

Choosing your glass

Every Slimline window comes with a 28mm argon filled, low emissivity unit and a warm edge spacer bar as standard. You are not paying extra to reach a decent starting point.

Option What it does Standard or upgrade
Argon fill Better insulation than air Standard
Low emissivity coating Reflects heat back into the room Standard
Warm edge spacer bar Cuts heat loss and condensation at the edge of the glass Standard
Toughened safety glass Required by Building Regulations in some positions. We will tell you where Where required
Acoustic glass Worth it on a main road, but only ever as good as the fabric of the building around it. Ask your adviser Upgrade
Laminated security glass Holds together if broken Upgrade
Obscure and patterned Bathrooms and overlooked windows Upgrade
Leaded and Georgian bar Period elevations and conservation areas Upgrade
Upgraded thermal unit Takes the whole window to a 1.0 U-value Upgrade
Triple glazing Best performance, heaviest units Upgrade

Your guarantee

Frames, glass units and workmanship 10 years
Moving parts and hardware 5 years
Insurance backed guarantee QANW, as standard
FENSA certificate Issued automatically on qualifying installations

The insurance backed part matters: your cover survives even if we are not here to honour it, and we provide it even on installations that do not qualify for FENSA. Most local companies do not.

Questions we get asked

How much do Slimline uPVC windows cost?

From £1,249 per window, supplied and fitted, including VAT, on the basis set out above. Prices are indicative and your quotation is the accurate figure.

Can you match my existing windows and doors?

Usually. Slimline is designed alongside the rest of our range, so a new front door will match. If you are replacing in phases we record your finish so the second phase matches the first. Bring a photo to the showroom and we will tell you honestly whether we can match what you have.

Do I need planning permission?

Usually not, but you might if your house is listed or sits in a conservation area. We will flag it at survey if we think you are affected.

Will I get a FENSA certificate?

Yes, automatically, on every installation that qualifies. You will need it when you sell the house, and we hold a copy in your customer portal.

What happens if something goes wrong in a few years?

Call us. Your workmanship, frames and glass are covered for 10 years and moving parts for 5, backed by a QANW insurance backed guarantee. The Glass and Repairs Surgery at the Guildford showroom is open Tuesday and Thursday afternoons and Saturday mornings.

Can I buy the windows without installation?

Yes. We supply only if you are arranging your own fitting.

Ready to get a quote?

You’ll speak to a real person, not a call centre. We’ll talk you through options, no pressure.

Pricing, finance and page notes

* Prices are indicative starting prices, reviewed regularly. They are based on an 1800 x 1200mm window in white with two side hung openers, a fanlight and a fixed pane below, supplied and fitted including VAT, and an order of four windows to the same property. Colours and woodgrain finishes cost more.

** Finance is provided by Dopple, not by Sheerwater Glass. Sheerwater Glass Ltd is an Introducer Appointed Representative of Social Money Ltd, trading as Dopple, which is authorised and regulated by the Financial Conduct Authority, firm reference number 675283. We introduce you to Dopple and we do not lend or give credit advice. Applications are made through our finance portal and all lending is subject to status and affordability. Dopple provides the rate, the term options and a representative example before you apply.

Specifications vary by window style, so a figure given here for a Slimline casement may not apply to another style, size or material. What governs your installation is the specification in your written quotation and signed contract. If a particular figure matters to your decision, ask your surveyor and we will put it in writing.