Quality sliding and casement sashes, double glazed with our high performance units

Due to popular demand Slenderpane are now offering fully glazed sashes to suit existing frames together with a complete window option.

As with our high performance double glazed units our joinery is top quality with every attention to detail and available in ten working days.

A variety of specifications are available, please visit our quick quote form below.

Sliding and casement sashes

Slenderpane Window Quick Quote Form

It's quick and easy to use and is guaranteed to speed up your standard quotes and orders.

For all standard orders we aim to get back to you within eight hours and all orders
within two working days.

Just place a tick in the relevant boxes to revceive a detailed quote.

Please specify aproximate sizes, quantities and configuration
(your ref., quantity, description, width, height, thick)

We only use the best quality timbers and all are certified from renewable resources.

European Redwood: Economical. Must be maintained to ensure durability. Carries a 10 year warranty

Hardwood Durable: Carries a 25 year warranty against fungal attack and rot.

Accoya. More expensive but very durable and stable. Carries a 50 year warranty against fungal attack and rot.

There are many glazing options including historic glass and leaded glass. The priced schedule includes high performance slim units incorporation softcoat low energy glass and krypton gas filling. Krypton gas is a dense inert gas with superior thermal properties to argon gas. The double glazed units come with a 10 year warranty.

For toughened glass (glazing less than 800mm from floor level must be toughened). Toughened Glass and Annealed Glass is despatched within 6 days of receiving your order.


Spacer Colour
The glazed units are manufactured with warm edge super spacer which is available in two colours, white and black. Black is good for slim units. It creates a shadow line helping to give the appearance of single glazing.

Glazing method
The priced schedule allows for glazing with timber beads. Putty glazing is also available for an additional cost of £3.00 + VAT per pane.

Add Putty Glazing:

Some of the other glasses available:

We use a top quality microporous paint system.
The priced schedule includes for factory priming. This is just a protective coat and is not decorative.
We do not recommend fully finishing sashes when they are to be fitted into existing frames but we can offer a pre‐dec service where the sashes are prepared, primed and undercoated ready to receive a final top coat after installation.
We offer a fully finished option on complete windows.
Any colour can be matched if we are provided with the B.S. or Ral number.
We can offer a dual colour option, different colour inside and out, for a price uplift.

Delivery and Installation/ Measuring

We offer a nationwide delivery service. Delivery costs are dependant on location.
Goods can also be collected from our workshop.

If Delivery, please add postcode.

Installation/ Measuring Service
We offer an install and measuring service in the following post code areas.
We can only give a budget costing at quoting stage. Once given an order we will attend site and take detailed measurements. We will assess the installation and firm up our install quotation prior to commencement.

Generally your install quote will include the following:
Our installers are directly employed by us, we do not use subcontractors.

Included in your quotation:

  • Provide floor protection to walking areas
  • Provide local floor protection around the window area
  • Remove architraves and window boards and cart away where applicable
  • Remove the old windows and cart away from site
  • Fit the new windows or sashes into prepared openings and ensure that the windows are operating perfectly.
  • Point and seal around the window brickwork reveal externally
  • Fit new architraves and sill boards where applicable
  • Carry out any minor plaster repairs affected by the work
  • Clear all debris and vacuum clean the immediate work area

Not included

  • Redecoration to walls internally or externally
  • Wall tiling affected by the works
  • Works to stone sills externally
  • Replastering areas of blown or cracked plaster

In the case of fitting sashes - works to the existing frames.
Blown plaster is where plasterwork has lost adhesion with the brickwork and is indicated by a hollow sound if tapped. If blown plaster is distubed it would need to be removed back to where the plaster is sound.

Please clear work areas prior to our arrival.

Curtains, Blinds and Shutters
We have not included for removing or replacing curtains, blinds and shutters, however we would be happy to do this for an additional charge.
Whereas every care will be taken we can not accept and liability for any damage that may be incurred with the removal and refitting.
The work would be charged on an hourly basis at the rate of £37.50 per man per hour + v.a.t. at 15 minute intervals. (Providing an additional site visit is not required).

Post Code areas covered for install and measuring service:
OX, AL, HP, HA, RG, LU, MK, UB, SN, WD, SL, TW and West London, South West London and North West London

Self Measuring
We only require approximate dimensions for quoting. Approximate width, height and
thickness will suffice.
Once the order is placed we will require accurate measurements. The following guide will assist in measuring.
If you do not require installation but would prefer us to measure we can offer a
measuring service within the post codes areas listed. Cost will depend on location.
Please see the attached diagrams to assist in self measuring.
Basic requirements:

  • width
  • height
  • thickness
  • width of stiles
  • depth of bottom rail
  • meeting rail width (sliding sashes only)
  • horn details (sliding sashes only)
  • sill projection

Install Required