Double glazed sash windows. A buyers guide

Double glazed sash windows: A buyers guide.

Sash windows have been an iconic look for many older buildings and in recent years have seen a comeback in popularity. The standard sash window has many double glazed sash windows benefits over a hinged window, primarily as a space saver, but also a much more traditional look. Sash windows do not need to be expensive to upgrade to double glazing, as well as reducing draft from poorly fitting or worn frames. In addition, modern designs can allow for a range of opening styles which older frames were unable to offer. For example, the bottom section can be mounted on a series of hinges offering two different ways to open:

We will focus on the different options available in upgrading to double glazing for your sash windows. However, first, we should look at the benefits of moving to double glazing and improving the frames of older windows.


Single vs. double glazed

Many properties in the UK still have traditional single-glazed sash windows. Despite how nice they look, they are a real weakness when it comes to heat loss. Single glazing is not as energy efficient as there is no barrier between the internal heat and the outside cold. This results in heat being lost through windows much more quickly than through brickwork as there is a much thinner barrier. Double glazing is an effective way to reduce this as there are two panes of glass (double the thickness already!) and a thin layer of inert gas (usually argon) between the panes. This acts as an insulator and keeps more heat in the home, reducing energy bills and increasing energy efficiency. Rooms will warm up quicker when you turn the heating on and stay warmer for longer.

The other consideration is the age of the window frame. Many old frames utilised a pulley system, built into the frame, to help lift the lower pane and keep it in place. Over time this causes wear on the mechanism and on the wooden frame itself. Added to this potentially some rotting of the wood, the frame itself will not fit as effectively and cause drafts. Not only is cold air getting into the home, which isn’t pleasant, but warm air is escaping causing you to heat the cold draughts that used to come around the edges of the old windows should be a thing of the past.


Upgrading an existing sash window

To begin with, it may be worthwhile to consider if refurbishing your existing sashes is a viable option. If they are “too far gone” then you may have no choice but to replace them. However, if the wood is in decent condition and it’s just a matter of functionality or upgrading to double glazing there are ways to do this that can be very cost effective.

Adding internal secondary glazing is an option that has been successfully used many times in many homes. The approximate cost to fit secondary double glazed panels on the interior of a sash window can start around the £200 to £250 per square metre mark. This method will give you the benefits of double glazing with a much reduced cost and without the hassle of replacing the whole frame. However, this may be a temporary measure in older windows as the frame may not have a huge amount of ‘life’ left and will need to be regularly checked for damage and rot.


Replacement of a sash window

In cases where the window frame is not in good condition, or if you just want to update the look of your home, then a full replacement if the best option. Whilst this is more expensive than upgrading existing sash windows, in the long term this can be a much better option and you have more choice available for the style, design and materials used.


Materials – uPVC sash double glazed windows 

Sash windows As with any double glazed window you can opt for a uPVC sash window. When you choose uPVC sash windows for your period property window replacement you get a wealth of benefits compared to timber. They include:

  • Low maintenance – Gone are the days of the sanding down and re-painting involved with real wood. With only the occasional wipe down, uPVC windows will stay looking like new for years to come.
  • Durability – Modern uPVC is extremely durable. Whereas timber can be compromised by rot and insect infestation, uPVC provides a durable and weather resistant finish to protect your home.
  • Cost-effectiveness – Traditional timber is expensive. When it comes to budgeting, uPVC windows are always the most cost-effective option.

For many people, they opt for uPVC simply because it is cheaper. In fact, you can replace a wooden sash for a uPVC equivalent for about £750, while a like-for-like timber replacement may cost nearer £1350.


Materials – Timber

However, timber window frames tend to last a lot longer and uPVC can fade and become discoloured by UV rays. The fact is that most people are looking to replace their original timber windows, from properties built in the late 19th or early 20th century. This demonstrates that if correctly looked after, wooden sash windows can last. The fact is though, in order for them to last this long they do require regular maintenance – if the frame lacks paint or varnish, the wood will begin to rot very quickly. Also make sure if you do decide to go for timber sash you choose hardwood windows since these are the ones that will last!

uPVC double glazing will not last nearly as long – in terms of lifespan, many glazing companies offer a 10-year guarantee on their uPVC window frames. The lifetime of a uPVC has been set at 35 years by BRE (the building research company), but still this is far less than the timber frame windows (provided they are maintained correctly). Having said that, they do require very little maintenance over their lifespan.

The choice you make may come down to cost, but companies specialising in sash windows will be able to create most designs and styles in wood and uPVC. If your budget can stretch to a timber frame then this will last a lot longer if maintained, but it is recommended to check that the wood has been sourced ethically.


Other Points to note

Estate agents often come out with the classic line ‘properties with timber frame windows look better and sell for more.’ Well, in some cases that is true but like many things, beauty is in the eye of the beholder. The truth is that good uPVC windows look very similar to the wooden sash windows – but this really does come down to a personal preference.

Some properties in certain areas of the UK will have restrictions on the type of changes that you can make to the appearance of (and the material used to replace) new windows. For example, if you live in a listed building or are located in an AONB (Area of Outstanding Natural Beauty,) there could easily be local restrictions in force. If you are unsure, please check with your local planning department before doing anything.


UPVC French doors – a buyers guide

uPVC French Doors: A buyer’s guide

French doors can add an elegant and classic look to any home, offering an easy flow through the home and linking outside spaces to the home effortlessly. French doors have been popular in British homes for a long time and the classic look will never go out of fashion. There are three options for homeowners in the modern market; French doors, Sliding Doors and Bi-folding doors. French doors are perfect for a medium opening, with two doors which open from the center to give the feel of a large, unobstructed gap. This gives a much wider area than a single door and provides easy access with no central bar or pane of glass, such as you would find on a sliding door. Sliding doors have become less fashionable in recent years and have been criticised for people walking into them and knocking them off their runner! Bi-folding doors are excellent for a large opening but are often excessive for a medium space as they are costly for a limited space.

UPVC French doors

French Door Materials

There are significant differences in the 3 types of material used for French door manufacture each one has its own features.

Timber: The main issue with using wooden external French doors is that, if not properly sealed, timber will saturate or dry out. This “instability” is what causes timber French doors to deform. They can develop draughts from gaps surrounding the door when the wood shrinks as it dries out or sticks & jams when the wood swells as it absorbs water. However, with good maintenance, hardwood timber doors will last 40 or more years, much longer than other materials.

Aluminum: Aluminium French doors are a good option, being very light and strong. However, also
being made from metal, they are cold to the touch.
The metallic structure of the frame necessitates a thermal break between the inside and outside
surfaces. If this thermal break is not made well, then the frames will transmit heat, cold and even
develop condensation on the inner surfaces.

UPVC French doors: This material has such a lot of things going for it. Light, strong, cost-efficient and a natural
insulator, UPVC frames used for French doors offer the best features of all the other material
combined. Most uPVC doors will last 20 or more years, giving excellent value for money and with a
wide choice of colors on the market now, they are the most versatile. Most uPVC doors also come
with multipoint locking systems as standard, improving the security of your doors.
In addition, uPVC doors are very easy to look after. All that they need to keep them looking as good
as new is a wipe/wash clean. They will never need painting and should retain their colour. They are
not affected by bad weather such as rain, frost, and snow nor should the colour fade in strong
sunlight. The door will not warp due to a change in the air temperature and moisture as a wooden
door does.

Energy Efficiency and Insulation

upvc french doors The door should be well insulated to stop the cold getting in and the heat getting out of your home thus making them very energy efficient. If you have glazing in the door it should either be double or triple glazed. Another benefit of being well insulated is that they should reduce noise levels inside your home if you happen to live on a street that is busy with traffic passing by. A good indication that your door has a quality seal is that when you close it shut it should do so with a good solid feel.
To make the doors as energy efficient as possible, a standard UPVC French door is fitted with double glazed sealed units. To further enhance the performance, the sealed units can be filled with Argon gas and low-emissivity glass can be substituted for standard glass. Some companies are offering triple glazed windows as well but always look for the A+ rated windows as they will be the most energy-efficient available. The UPVC frames themselves are multi-chambered (much like a honeycomb), which also benefits the overall energy efficiency of the door set. If you’re interested in making your home more eco-friendly, read our guide


As mentioned previously, uPVC doors are often the most secure set of patio doors on the market. The security of French doors has, in the past, been subject to question. Modern French door designs have addressed previous criticism and can now incorporate security features such as:

1. Multi-point locks that engage at the top, bottom and sides
of the frame.
2. Deadbolts that secure the doors to the top & bottom of the
outer frame.
3. 5 lever mortice key locks on each door leaf.
4. Pinless hinges. 3 sets per door.
5. Internally operated thumb-turn locks (cannot be operated
from the outside).
6. Internally glazed & beaded so the glass cannot be removed
from the outside.
7. Toughened, tempered safety glass.

All these features mean that uPVC French doors are much more secure than their rivals and you can be secure in the knowledge that your doors are just as resilient as your hardwood front door! To make sure you are fully secure, buy a uPVC door with a British Standard PAS 24-1. This means that the door and frame, as well as the locking mechanism, have successfully gone through several physical tests.

Boiler Plus – Everything you need to know

Since 6th April 2018 the legislation around heating manufacture and installation in the UK has changed, and there are some big changes. What is this Boiler Plus

These changes have been named Boiler Plus and were introduced by the Department for Business, Energy and Industrial Strategy (BEIS). They address the energy efficiency of heating systems and have raised the bar for both manufacturers and installers.

The minimum efficiency level of all boilers manufactured and installed will be set at 92% ErP. Most A rated boilers are already working at this level of efficiency already, with a few companies needing to improve their efficiency slightly. The main motivation behind the change is to phase out inefficient boilers and reduce carbon emissions in line with targets set by the EU. It forms just part of a wider plan known as the Government’s Clean Growth Strategy which aims to combat climate change and provide UK homes with greater comfort and lower energy bills.


HHIC say:

“These changes will mean far more conversations between installers and their clients about the requirements set out in this consultation and the options that are available to meet them.”

“This will clearly increase consumer’s awareness of what controls are and how they can be used to get maximum efficiency from the new system they are having installed”

“By mandating certain controls, such as programmable timers and thermostats, the market for these products will inevitably be widened while consumer awareness of them and their benefits will also inevitably increase”

Boiler plus

What are the penalties?

Installers who fail to install boilers in line with these new Building Regulations will be breaking the law and could be prosecuted by Building Control. The Gas Safe Register can also refer safety concerns to the HSE (Health and Safety Executive). Invoicing a customer for work which they claim to be legal but is not is also to be considered fraudulent under Trading Standards. This could lead to a fine or, in cases of serious fraud, imprisonment. Homeowners who knowingly allow non-compliant work to be carried out could also face prosecution and fines of up to £5,000.

What are the options to comply with the law?

HIIC have provided this helpful diagram to help both homeowners and installers stay on the right side of the law. What is interesting is that the law only applies to combi boilers, as nearly all boilers will come with a timer and thermostat. There has been criticism from some installers that this legislation assumes that only combi boilers are being fitted and other systems do not need other efficiency related devices. However, we will focus on how an installer can stay compliant with the four measures which need to be installed alongside a combi boiler. These four measures are: FGHR, Weather compensation, load compensation and Smart Heating controls.


What are the different measures to comply?

It is worth highlighting that only one of these measures must be installed to remain compliant with the law. In an ideal world all the measures would be fitted to each boiler, but this will add extra costs. Depending on the manufacturer there is a variety of costs associated with the installation, but this is much cheaper than the fine for non-compliance.

What is FGHR?

A Flue Gas Heat Recovery (FGHR) is a device designed to improve the energy efficiency of the boiler by recycling the heat from the flue gases which would usually be lost into the atmosphere. Instead, this heat is used it to preheat domestic hot water. A FGHR will cost roughly £1000-2000 for installation, depending on the brand and size of the boiler.

What is weather compensation?

Weather compensation devices enable the boiler to read the outside temperature via a sensor so that the boiler can adjust the temperature of your heating accordingly. Most weather compensation sensors are standalone units fixed to an exterior wall.  A weather compensation kit can be purchased for as little as £30, up to around £250 for better quality kits.


What is load compensation?

Load compensation measures the response of the heating system and adjusts the flow temperature based on what is needed to reduce fuel consumption. A full system will cost anywhere from £500 to £1500.

What is a Smart heating control?

Smart heating controls have had the most media coverage, especially with a push from British Gas for their Hive controls and Google with the Nest. These heating controls allow you to adjust temperature and control when the heating comes on from your phone because they’re connected to the internet via your router. They also monitor and learn your behaviours, leading to a more energy efficient home as the smart control will adjust the thermostat automatically when you are not home. Smart heating controls retail at between £150 and £250, although many manufacturers are offering incentives for new customers with free smart heating controls with installation. See our post on smart thermostats 

Most Gas safe installers are opting for a smart heating control, possibly because of the incentives from manufacturers and many homeowners like the link to technology. However, for a cheap and easy solution installing a weather compensation kit will keep you on the right side of legislation and cost a lot less for installers and homeowners.

Vaillant boilers or Worcester boilers? Which is better?

Vaillant VS Worcester

Vaillant or Worcester



Vaillant and Worcester Bosch are both domestic heating and hot water product manufacturers. Both are highly regarded brands with consistently high customer satisfaction scores. Both make all types of boiler, conventional boiler, combi boilers & system boilers. When trying to decide between a Vaillant and a Worcester boiler, there are a few things to consider, e.g. price, size, control, and energy efficiency. First, we should get an overview of the two companies and the range on offer. Ps if you’re interesting the in the: Pros & Cons of Combi boilers VS Conventional boilers .

So Vaillant or Worcester? Let the battle commence. Read on…


Vaillant Boilers 

Valliant is a German company which has been a key player in the heating market for over 135 years and now sells its products in more than 80 countries. Vaillant was founded in 1874 and is currently Europe’s second largest company in this sector, focusing on energy-saving and environmentally-friendly products with polished German engineering.


Their range provides options for all sizes of homes and different budget options from the Ecotec Pro & Ecofit pure to the more premium Vaillant Ecotec Plus, which now comes with a 10-year guarantee for Vaillant advance members. Their boilers range in price from £740 to £1,500 depending on their size and sophistication. Most boilers come with a standard 2 to 5-year warranty, which can be extended up to between 5 and 10 years at an additional cost. (Excluding Vaillant Plus range).


In general, Valliant customers are happy with their range of boilers. Many claims that Vaillant boilers are particularly easy to use and are made to a good standard. Whilst some people have had issues with their boiler, they report that problems have been dealt with quickly by the company’s team of 200 specialist engineers.

Worcester Bosch Boilers 

Worcester was founded in 1962 in the United Kingdom and later acquired by Robert Bosch GmbH in 1992 to form part of the Worcester Bosch Group. Similarly to Vaillant, Worcester Bosch makes energy-saving goods its main focus, while also creating schemes that promote activities dedicated to conserving the environment for future generations. Find out more here.


Their range of domestic combi boilers includes the Greenstar Junior and Greenstar Si series. Their Greenstar Ri series is a popular conventional boiler for more traditional homes that use a cold water tank and hot water cylinder. They also produce system boilers such as the Greenstar 12i, 24i, and 30CDi. Their boilers range in price from £570 to £6,188 and are supplied by certified Worcester Bosch installers. Their boilers come with a standard 5-year warranty, with an option to extend to 10 years for free if the boiler is fitted and maintained by a certified Worcester Bosch installer.


Worcester Bosch has a strong reputation with very few negative reviews. They score very highly for their reliability, although some customers have reported that the controls on their boilers can sometimes be difficult to use.

Worcester boiler


Both brands have won several awards over the past decade and Worcester Bosch has won the Which? Best Buy Awards in the gas boiler category for seven years running. Their boilers have also had a 6-year run at an overall rating of 92% for customer satisfaction and engineer recommendations.

The Vaillant Ecotec Pro range, in turn, was also awarded the Which? Best Buy Award in 2016 but can also claim to be the only boiler brand to have also been awarded Quiet Mark status by the Noise Abatement Society.

What are Installers saying

On installers have commented on the build quality of the two brands, with ‘moles’ commenting:

On opinions were divided, with many commenting that there is little to choose between the two. However, it is worth noting that several installers commented that they have to repair Vaillant boilers much less frequently than Worcester Bosch:


And Frank Finn, of Frank Finn plumbing, echoes this in his own blog comparing the two brands:

“Considering all the factors and individual needs, my verdict would favour the Vaillant boilers.

One of the things we find helpful from Vaillant is there allowable flue length, a valiant 832 could go as far away from an outside wall as 8m whereas a Worcester 29cdi would be 6.4m giving you greater flexibility on the positioning of the boiler.

We have found the Vaillant to be quite easy to fix when things do go wrong cutting down on long call out times. Whereas we have found with Worcester, they have a few parts which are not easily accessible, without removing other parts on the boiler.”


Also, if you head over to some of the gas engineer groups on Facebook, a lot of engineers joke about the impossibility of repairing Worcester boilers, some of the problems that come up, that should not come up, like the replacement of parts that should be easily replaceable on a routine visit, require the whole boiler stripping on.

Worcester combi boiler


Both brands make excellent A-rated boilers and come with very few complaints and high customer satisfaction rates. In my opinion, I would recommend the Vaillant boiler range over Worcester Bosch for two reasons; firstly, Vaillant boiler parts are more readily available, last longer and have few complaints about wait times for repair and secondly the Quiet Mark award. There is very little difference in price, but Vaillant are often slightly less expensive when including installation costs, but this saving might be used to offset against taking an extended warranty, that being said the Vaillant Ecofit Pure range offering a 7-year guarantee & the Ecotec plus range now offeri10-year year guarantee is pretty strong!

From the comments of multiple installers, I would expect most Vaillant boilers fitted now to last long after their warranty expires, if services and maintained properly, whereas Worcester Bosch may not last quite as long.


Feature Vaillant Worcester
Quality of materials 9.5/10 (plus range) 8.0 (CDI range)
Reliability 8/10 9/10
What installers say 9/10 "easy to work on" 6/10 can be expensive & a nightmare to repair
After Service 8/10 "Vaillant are very responsive" 8/10 "Worcester look after their customers"


Vaillant is the overall winner!

Rich, Green geek,


The Solar Battery – An Idiots Guide.

Solar Battery: An idiots guide

There have been several government schemes to increase the number of houses using Solar panels, with incentives offered to homeowners including free installation. Once solar panels are fitted you can reduce your electricity bill by harnessing the power of natural sunlight to produce energy. Whilst there is a wide range of solar panels available, one of the most important parts is often neglected; the storage of solar power.

solar panel battery

What is even better, is that you don’t need solar panels fitted to use solar batteries. If you are on an Economy 7 (night and day) tariff you could use solar batteries to store energy to use during peak times, paying the night tariff to charge them. However, let’s focus on using solar batteries linked to a solar panel system.

What are solar batteries & how do they work? 

Solar batteries store the energy produced by solar panels and many homeowners have been caught out by purchasing poor quality batteries and then not seeing the savings expected. By storing solar energy in a good quality battery, you not only save the power for when you need it, such as a cloudy day but reduce your bills even further. By storing energy for when you need it you don’t need to buy additional energy from your electricity provider. The free energy produced by solar panels lasts even longer!

Solar batteries help make homes even more self-sufficient and less reliant on the national grid for electricity. In an ideal world, every home would be self-sufficient, but we are a little way from that yet! With cuts to the benefits of Feed-In-Tariffs (how much you can be paid for the extra energy produced by solar panels), it makes even more sense to purchase a good quality solar battery and safeguard your future energy costs.


This is a great video explaining the concept & how the solar battery works 


What are the best solar batteries?

This will entirely depend on what level of storage you want and how often you are likely to use the battery for stored energy. More and more companies are entering the market and creating a wide range of sizes, from 1kWh (kilowatt-hour) to 14kWh. The bigger the battery, the more you can store.

A kilowatt-hour is the standard unit used by all energy companies to measure your use and refers to 1000 Watts of power used per hour. The average home, depending on size and occupants, will use between 2000 kWh and 4,500 kWh of electricity per year. One kWh is roughly the same as watching TV for three hours or boiling a kettle ten times.

A typical solar battery will cost between £2000 and £4000, but most people will pay less than £4000 for a good quality battery. Most batteries come with a 10-year warranty, protecting your investment for a long period of time and guaranteeing you won’t need a new one for a while. Unfortunately, solar batteries do not currently have the same longevity as solar panels, so you are likely to need to replace them at some point, but they are getting better, and more companies are extending the life of their solar batteries. See Tesla Powerwall .FYI – Post coming soon! 

Tesla powerwall


Lead acid batteries can be purchased for a lot cheaper, but they tend to be less efficient and wear out much more quickly. Lithium-Ion batteries are usually the best option for a long-term solution and most manufacturers only make Lithium Ion batteries as they are much longer-lasting.

Some of the more recent developments in solar batteries include linking to smart technologies such as an app or Wi-Fi, which can display a range of information including the charge level of the battery, usage, and savings made.

Anything else I should consider?

Always get three quotes from registered installers and check the warranty and how many charge cycles each battery is guaranteed for. Like any rechargeable battery, the more it is used the less efficient it becomes and having more charge cycles means it will last even longer. Typically, you can expect 5,000 to 10,000 cycles, but some companies are offering an unlimited warranty on charge cycles now.

Solar batteries are not recommended for a D.I.Y. enthusiast to fit themselves and work must be carried out by a registered engineer. Many suppliers will not sell solar batteries to members of the public and will insist on seeing the correct documentation before sale.

Always bear in mind there will be some maintenance costs involved with a solar battery and the engineer can explain how regularly you should have the battery maintained and the expected costs over the lifetime of the battery. These costs will vary by manufacturer and model so be careful not to get caught out with unexpected future costs.

The engineer can advise on the best type of solar battery for your needs, as well as advising on the placement of the battery. They are not small units and you will need to ensure there is enough space to fit them. You will also need to know the type of power (AC or DC) and whether your solar panels allow for a retrofitted battery (most do, but some batteries are specific to certain systems).

Thanks, Rich,