Q. Should the sides / insides of my sash windows be painted?

No, The insides of the sash window are normally left unpainted, this is how they have always been and it serves no purpose to paint them.
Areas which should be left unpainted are:

  1. The insides of the case (visible when the top sash is pulled down).
  2. The insides of the case (visible when the lower sash is lifted up)
  3. The top of the top sash.
  4. The sides of both top and bottom sashes.
  5. Behind the baton rods / staff beads if they have the simplex system fitted.

The below article is from the building conservation website website on the correct order of how to paint traditional sash windows.

Procedure for internal painting

  1. Slide the outer sash down a little and raise the inner sash slightly, leaving a gap top and bottom.
  2. Paint the glazing bars and the surfaces of the inner sash including the top surface of the meeting rail and the underside of the bottom rail.
  3. Then paint what you can see of the outer sash, including the face (but not the underside) of the meeting rail.
  4. Now slide the outer sash up, but not quite closed, and lower the inner sash by gripping it from the outside so that you don’t touch the wet paint.
  5. You can now complete the painting of the outer sash, omitting the top surface of the top rail. Ideally you should leave the sashes in this position until dry.
  6. According to how your colour scheme relates to the outside paint colour, you can either paint the pulley stile at the same time as the sashes, or later. If painting at the same time, then the stile, parting bead and staff bead can be painted in sections as the sashes are moved up and down. Pull the sash cords out when you are working behind them (painting the cords makes them more likely to break); paint the pulley housing but not the pulley itself, otherwise it will jam and the sashes will not run easily.
  7. Finish off by painting any inside linings, frames, and shutters. Tackle one component at a time if possible, and complete it before moving on to the next. Any framed elements such a shutters or lining should be covered in the following order; mouldings and panels (at the same time), muntins, top rail, middle rail, bottom rail, and stiles. Remember to ‘lay off’ (the final brush strokes) in the same direction as the grain of the wood.

Procedure for external painting

  1. Reverse the sashes as described above and paint all visible surfaces except the top surface of the top rail of the inside sash. The pulley stiles can be painted at this time also.
  2. Return the sashes to an almost closed position and complete the painting of the inner sash and the pulley stiles, together with the cill.

Listed Buildings Consent and VAT

If you live in a listed building, and you are planning to make any alterations to your windows – such as double glazing, you will require listed buildings consent. This is not required if you are only renovating the windows.

If your property has windows which are not sash and case, such as PVC or pivot windows, and your property is listed. Your window work should be zero rated for VAT as long as the listed building consent is approved.

There is also a VAT reduction on draught proofing works to sash and case windows. This is sometimes incorrectly applied to the whole job. The 5% VAT rate applies to the draught proofing element of the renovation only.

When we supply you with a sash window renovation quotation, it is split into two parts. The renovation part which is standard 20% VAT and the draught proofing element at 5%.

If you are in any doubt, contact your local planning authority and the HMRC directly.

Edinburgh: Planning Helpdesk: 0131 529 3550

HMRC VAT helpline: 0845 010 9000

Q. What is the Simplex Easy Clean System?

The Easy Clean System, sometimes refereed to as the simplex system, is a very simple way of allowing access to the outside of your sash windows.

It is used on upper levels of a property to allow for window cleaning and general maintenance. It is not generally used on ground floors where the window can be accessed from the outside.

It consists of 4 different fittings, a cord clutch, a cord plug, a sash fastener and the slotted hinges.

The fittings allow you to open the bottom sash like a door, making maintenance and cleaning straightforward.

The easy clean system is the only system for traditional sash windows. It is available in a number of finishes, steel, brass, chrome and satin, to ensure your sash windows are looking their best.

Q. Will my sash windows last for years to come, or should I consider full replacement?

A. The vast majority of sash windows in Edinburgh can be fully refurbished and will outlast a modern replacement. Georgian and Victorian sash windows have been manufactured from slow grown pine which is a far stronger, more durable timber. When your sash windows are fully refurbished they will last another 100 years – as long as the exterior paintwork is maintained.

Q. Can I install double glazed sash windows in my property?

As a general rule yes. Even listed buildings are now allowed double glazing but there are certain restrictions on this and it needs to be authorised by the local authority first before any work is carried out.

Q. When cracked glass is replaced will the sash window still be weighted correctly?

A. No, modern glass is 4 mm thick and the original was only 2mm. The windows will need to have additional weights added to ensure a perfect balance.

Q. What other works are carried out when my sash windows are overhauled?

A. Cills are replaced when necessary, exterior pointing upgraded, ironmongery replaced, rotten timbers replaced and cracked panes are replaced.

Q. Is our system suitable for conservation areas and listed buildings in Edinburgh?

A. Yes. To the eye your sash window looks exactly the same, because the brush seals are hidden behind the baton rods and parting beads. Overall this complies with current planning and listed building regulations.

Our sash window renovation techniques are based on Historic Scotland’s restoration guidelines.

Historic Scotland also have an excellent and informative guide for owners and occupiers on how to maintain your sash and case windows. Download their Information Guide on Sash and Case Window Maintenance.


Q. Do slimline DG units meet with current building standards?

As a general rule no they don’t. Most units refered to as slimline refer to 14mm units 4/6/4. This is a compromise position from the local authorities / Historic Scotland whereby they allow double glazing to be installed in historic properties with the understanding that preserving the look of the property is more important than the performance of the units – so they generally have a lower u  value than you would achieve with a larger cavity unit. You will normally require to get approval from the local council before carrying out installation works.


Q. Why is the lifespan shorter for DG units on astrigalled windows?

DG units all degrade with time, as the seal which retains the gas eventually allows moisture into the unit. As a rule of thumb the depth of the sealant lasts one year for each millimetre of sealant. A non astrigalled window will have an 11mm seal around it and a thin astrigalled window will have a 7mm depth of seal round the unit so, so you would expect to get 3 years less lifespan from low sightline units.


Q. Do I need to replace the whole window if I have a failed DG unit?

No, its fairly straightforward to replace a dg unit, the process is similar to replacing a cracked pane in a single glazed window.


Q. What is Low E Glass?

Low E or low emissivity means that the glass has had a film applied to one side of the glass during the production process which improves the energy efficiency of the double glazed unit and will normally be used on double glazed units particularly when slim cavity dg units are used.

  • Low E Windows help to reduce Energy Costs.
  • Low E applied to windows helps block infrared light from penetrating the glass from the outside.
  • Low E Windows Reduce Destructive UV Rays. These coatings help reduce ultraviolet (UV) light.
  • Low E glass has a slight blue/green tint to it
  • Low E Windows Do Not Block All Natural Light.

Read more about Low E Glass here

Q. Does Draughtproofing Sash Windows Cut Down Heat Loss?

A. Yes, modern materials are used to upgrade the traditional sash window, improving overall heat loss. As part of the draught proofing process, baton rods and parting Beads are replaced with new timbers that have an integrated brush system. The midrail of the bottom sash also has a routered weatherseal fitted. However while the draft proofing system for traditional sash and case windows is a huge improvement on the original design, it is not comparable to modern sealed window systems such as the tilt and turn and a draught proofing level of around 70% is to be expected. If you have working shutters and they are reasonably close fitting, they can also make a large difference to heat loss. A recent study by Edinburgh council and Heriot Watt University showed that the heat loss with single glazed sash and case with draft proofing and shutters were comparable to double glazed sash and case on its own.

Not found the answer?

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