My House Is Too Hot

Building Surveyors

If you need help and advise with regard to a structural survey (or building survey, as it is now commonly known; structural survey being the old term for it) or a structural problem or an engineers report, or you need a report specifically tailoring to your requirements please do not hesitate to call us for a friendly chat on free phone 0800 298 5424.

A common problem?

A problem that we think will get more common, is that we think houses will get too hot. We are of course not talking about all houses. We feel this will affect modern construction during summer months and hot spells.

We have had several phone call enquiries from people advising that their houses are too hot, what can they do about it? We have been dealing with one property where there is a family in the house with three children. The house is brand new and the level of heat in the house is consistently too warm during the summer months to be comfortable.

If your house is too hot open the windows!

The problem is more fundamental than opening the windows; it is the way the properties have been constructed with particular high levels of insulation and lack of thought with regard to the ventilation as these properties are sealed. This article discusses houses that are too hot and yes they have carried out the obvious measure of opening the windows; some of them all day and all night.

It's the way modern houses are built that makes them so warm in the summer

We typically get calls with regard to houses being too hot during the summer months when there have been several warm or hot days in a row or during humid still days when there is a lack of air movement.

We feel the problems are starting to occur because although houses look very similar on the outside to what they have always done, the thermal insulation standards now required within a modern property have been increased and increased over the years i.e. since the 1970's when we had a fuel crisis but more recently as we have become green in our ways. A modern house works on being airtight i.e. it will not leak any heat out and the heating being as efficient as possible so that you use less energy. Whereas an older style house has a less effective older style boiler (unless you have replaced it with a modern energy efficient boiler, but more about these later). What is termed as leaky construction? By leaking construction we mean non-airtight construction. We feel a lot more research needs to be carried out with regard to the modern levels of insulation that we are putting into properties and not just by those that gain from it i.e. the insulation manufacturers.

How is a modern property built?

So let's consider how a modern property is built. Whilst they can look as if they are constructed exactly the same as they were probably 100 or 200 years ago, with a brick elevation, stone elevation, or even render elevation (depending upon where you live in the country), and inside it looks like you have plastered walls, the construction within the walls is very different to how it was hundreds of years ago.

Firstly, the walls will have:

•  Cavity wall construction which means there is an outer and inner layer with a gap between.

•  Insulation. It will have insulation within the cavity and also it will use an insulation block for the inner layer of the walls.

So whilst the walls look similar on the outside on the inside there is a layer of insulation between you and the outside world. This means that the temperature inside, assuming the windows and doors are kept shut, reflects how well you have heated it inside. This may be a strange comment but by this we mean in an older property, with a different construction (that we will talk about shortly) you may heat the property but also the heat will leak out, hence the term sealed house for a modern construction.

Timber frame construction

Equally, timber frame constructions have got cleverer over the years. These can look to be brick from the outside. It will have lots of insulation inside and again because a sealed house is produced the amount that you heat the house inside is the temperature that you get. As we mentioned this may seem a strange comment however when compared with an older house it does not leak out.

Older houses leak heat?

How will the heat leak out? It will leak out via older style sliding sash timber windows that don't fit as well, or even front doors that don't fit, or through the walls themselves, which are now, as explained, insulated, or through the floors that are again now insulated, but probably mainly up through the roof, as heat rises and this is where you will find the main loss in older un-insulated properties.

So, we now have the fundamentals of the modern construction which is highly insulated in the floors, walls, windows and the roof and the older style construction of a house which we will talk about now.

How are older style properties built and what makes them different from a modern property?

Let's start by defining an older style property. Generally we would say the term relates to anything that has been built before the war years (by this we mean World War I and World War II), it can even be as late as properties built up to the 1970's and 1980's.

The 1970's was the time when we had a fuel crisis which made us consider how to insulate properties and reduce the expensive fuel costs.

We would say after this period of the 1980's and property booms of the 1990's the focus was more on how cheaply can we construct a property and the energy efficiency of it, although energy efficiency standards did increase as the Building Regulations (the national government regulations that require minimum standards) forced the majority of builders and developers to improve their standards.

Older properties are generally built with:

•  A solid or a suspended timber floor which is un-insulated

•  Solid walls without insulation

•  Timber or metal single glazed windows. Single glazed windows do not have good thermal efficiencies.

•  Roof would have been un-insulated originally; it may have been insulated after.

We do still come across properties that have roofs that are not insulated so you do need to check this.

Close boarded roof � no insulation

We have an old house that is warm in the winter and cool in the summer

  We can hear some of you saying that we have an older property and whilst it's not the warmest house in the world during the winter it is warm enough, and in the summer we notice it's lovely and cool on a warm day, so we don't understand why people complain about cold old houses. Older properties can be warm and comfortable in the winter months!?

You may well be lucky enough to live in an older style property that is built to a quality standard, rather than a quantity standard, as most modern buildings are, and the quality of workmanship means that the house isn't too draughty and that over the years radiators will have been added of a suitable size and type that heat the property well. There's even a calculation, which used to be called British thermal units that you could do to ensure that you do get the right level of heat. However, you have to remember that most houses were heated originally with a coal fire. Remember even the inside chimney was a new invention at one stage; they used to burn fires in the room with an open ceiling without a chimney.

Victorian Properties

Anyhow, we digress. The main point we want to make is that older houses can be warm and very comfortable. They do tend to have what is known as hot spots, be it a feature real fire or warm areas near radiators, and cooler spots, such as near draughty doors. If you have ever lived in a Victorian property which has the entrance door leading directly into the front room you'll know exactly what we mean when we say it is not pleasant sitting next to a draughty door during the winter months. However, with someone with an entrance lobby/hallway and in a house with modern central heating these houses can feel very pleasant during the winter.

We do want to go back to the main focus of this article, which is how hot properties can get in the summer and just point out that with an older property, due to the way it's constructed, the heat from outside can be absorbed by the outside wall, rather than passed into the property and because the older property was not built airtight there is air circulation within the property, via open windows or draughts, etc, that give a beautiful, cool feel to the house as a whole.

We use the term of mass wall construction as to the way these properties were built, rather than in modern properties where they are built with a more lightweight construction, with high insulation value, or the properties have a mass wall construction.

We are aware that SPAB (Society for Protection of Ancient Buildings) have been carrying out work for some time on the energy efficiency of older properties and argue strongly that they are far more efficient than modern energy efficiency reports make out.

They are measuring the insulation factor of them and other factors have come into play, such as mass wall construction.

We would refer you to the spab.org website for the latest information on this or to give them a call.

Thermal imaging cameras, what do they survey?

We have met Douglas Kent from SPAB (Society for Protection of Ancient Buildings) and we have jointly carried out some thermal imaging work with him on a project that he is carryout out. We understand to some extent his concerns with regard to how the modern energy efficiency report looks at older properties and rates them.

We are aware that he was involved in one property that was a Listed building. One of the main features was the decorative parjetting render outside and the energy efficiency report came back recommending that the outside of the house could be clad in insulation boards to make it more energy efficient (we hope our memory serves us correctly with regards to this).

Thermal Efficiency and Going Green

We feel that we have only just started on the road to thermal efficiency. One of the ways that we have started is with European agreement on the reduction in carbon, which in turn ultimately, many have said, has led to the introduction of compulsory emergency efficiency reports when properties are sold. Most importantly, we feel that what this has done has brought energy efficiency and being 'green', for want of a better term, to everyone's attention when they buy or sell a house, and as such the ethos of energy efficiency gets built into the very nature of what we do.

We particularly like the new three R's:

•  Reduce

•  Reuse

•  Recycle

However, we prefer be lean, be clean, be green:

To reduce the energy demand, the following energy efficiency measures

could be considered:

•  Draught proofing around doors, windows and external wall penetrations

•  Increased levels of insulation

•  Energy efficient lighting

•  Reduce thermal bridging

•  Fit chimney pillows (for any chimneys not in use)

To use energy more efficiently:

•  Replace boiler with a more energy efficient one

•  Insulate hot water cylinders

•  Energy efficient extract fans

•  When buying new appliances consider ones which are energy (and water) efficient

•  Fit click taps, flow regulators or aerators to taps and showers (reduces amount of hot water which needs to be heated)

Supplying energy from renewable sources:

You may want to consider generating some of your energy on-site using low or zero carbon (LZC) technologies. Appropriate systems for your property are:

•  Solar thermal (hot water)

•  Biomass stove / boiler (single room heating, whole house heating and hot water)

•  PV (electricity)

A heat pump may also be feasible; however this technology is most effective in houses which have good levels of insulation. There have been cases of very high energy bills because heat pumps have not been appropriate or have been sized and installed incorrectly.

We don't understand thermal efficiency properly yet

We would comment that we don't feel we understand thermal efficiency properly yet and indeed would refer you to our other articles on this:

•  How does the air move in your property?

•  Energy efficiency, have we got it wrong?

•  Energy surveys or energy condition reports -v- thermal imaging.

•  Thermal imaging

•  It is important to remember where builders come from

•  Listed buildings and character properties

•  Do all houses have condensation?

•  Condensation and cold bridging

•  Cavity wall problems

How do I keep a modern property cool in the summer?

We are afraid to say that in most cases we would have to come and see a property to advise you exactly, however we can give you some examples. Perhaps another way to say this would be you have to understand how big a problem you have, as well as how your house is constructed, before we can come up with a solution, but we will give you some ideas here that may help you.

Smaller things that make a difference to how hot a house is

We would suggest that you do a very basic survey of your own property. Having looked to see if there are extract fans in the kitchen and bathrooms, or a utility/laundry room and any area where there's a lot of warmth generated you need to vent quickly particularly the humid air.

Next we recommend that you have a look at the windows to see how well they fit. If it's a modern plastic double glazed window it is very important to see that it has trickle vents and air ventilation, although one of our surveyors does argue that trickle vents give next to no air ventilation. Some cases depend of course on their size.

Trickle Vents Defined

Small vents to the windows to allow air movement inside the property to stop a build up of fumes or humidity.

In some properties as well you will have a suspended floor. This will be traditionally in older properties a suspended timber floor; in more modern properties you sometimes have a suspended concrete floor. This can be for various reasons such as clay in the London area or radon in the Midlands and Cornwall and Devon areas. Either way, it does mean that air does circulate under the building which can be draughty in the winter and cooling in the summer.

These are the type of smaller amendments that can be made but such things have to be done with care. For example, we are keen on using humidity controlled extract fans in some cases, as these will automatically extract when the humidity gets to a certain level, but they are not right in all cases.

Larger things that make a difference to how hot a house is

Larger things that you may have to do to help your property from being too hot in the summer is to add an extension. This may sound drastic but in one case that we have dealt with, which was a modern property that was overheating, we put a small extension on the sunny side which reduced the large window area on this side. Yes, we know it looks good in Grand Designs and other property programmes but in reality it can be a pain as you are getting too much solar energy gain during the summer.

We added a small lean to construction which had a reduced level of glazing and was well ventilated. It added an extra storage space for the property and also, most importantly, stopped the build up of heat on that side of the house. It could be kept within this room that we then vented at roof level. We are not suggesting that this is necessary in the majority of cases, as we are after all practically minded, being chartered building surveyors, we look at doing extensions such as this, but it is amazing the difference it has made the property.

A too warm house can be used to your advantage

Finally we would add that the sun's resort of energy in the form of heat and light is free and good design can utilise this.

In years gone by we always did, for example in Georgian properties they were faced to catch as much of the natural light as possible, as we simply didn't have electric lights to help us in the darker months. Equally in turn, this meant that they got more of the sun's heat. Whereas, we find modern developers will literally try to cram as many properties into an acre of land as possible to maximise profits. Apologies to developers that don't do this, but we would say it's the majority that don't consider the aspect of the property any more.

We have been involved with one property where literally we have changed the front elevation round to best use the free sun that's available.

Equally, we have been to developments that use sunlight well and have been to one eco development where the houses, in our opinion, were not facing the right way to best utilise the free sunlight.

Where do I start if my house is too hot?

We would recommend of course having shutters or curtains shut on the sunny side of the house to stop the heat from getting in and equally to have the windows open to allow any heat that does get in to escape (of course, bearing in mind the practicalities of keeping your house secure).

You can give us a call on 0800 298 5424 to have a general chat with regard to other measures that you can utilise.

Independent professional property advice

If you truly do want an independent expert opinion from a chartered surveyor with regard to structural surveys, building surveys, structural reports, engineers reports, specific defects report, dampness issues, dilapidations, home buyers reports or any other property matters please contact 0800 298 5424 for a chartered surveyor to give you a call back.

Independent professional commercial property advice

If you have a commercial property, be it leasehold or freehold, then you may wish to look at our Dilapidations Website at www.DilapsHelp.com and for Disputes go to our Disputes Help site www.DisputesHelp.com .

Property articles to make you think?

We hope you found the article of use and if you have any experiences that you feel should be added to this article that would benefit others, or you feel that some of the information that we have put is wrong then please do not hesitate to contact us (we are only human).

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Expert opinion

If you truly do want an independent expert opinion from a chartered surveyor with regard to structural surveys, building surveys, structural reports, engineers reports, specific defects report, dampness issues, dilapidations, home buyers reports or any other property matters please contact 0800 298 5424 for a chartered surveyor to give you a call back.

If you have a commercial property, be it leasehold or freehold, then you may wish to look at our Dilapidations Website at www.DilapsHelp.com and for Disputes go to our Disputes Help site www.DisputesHelp.com .

We don't understand thermal efficiency properly yet

We would comment that we don't feel we understand thermal efficiency properly yet and indeed would refer you to our other articles on this:

Energy efficiency, have we got it wrong?

Energy surveys or energy condition reports -v- thermal imaging

Thermal imaging

It is important to remember where builders come from

Listed buildings and character properties

Do all houses have condensation?

Condensation and cold bridging

Cavity wall problems