Tag: period homes

  • HPH073 : How Alterations to Period Properties Affect Performance – with Richard Oxley from Oxley Conservation

    HPH073 : How Alterations to Period Properties Affect Performance – with Richard Oxley from Oxley Conservation

    Richard Oxley from Oxley Conservation explains why understanding an old house is such a vital first step to take before upgrading its performance.

    Richard Oxley

     

    Interview with Richard Oxley

    Richard Oxley began his professional life as a chartered surveyor. He then developed his interest in old buildings by studying for a RICS Diploma in Building Conservation and after gaining experience with a local historic building contractor, in 1997 he established Oxley Conservation.

     

    An Alteration is Something That Could Make a Change to How That Building is Used or Performs

    For the sake of energy efficiency this could mean, for example, secondary glazing or insulating the roof space, walls or underfloors.

     

    “Historic” and “Traditional” Properties are Not the Same

    The term “historic” relates to how a building is protected, with greater cultural importance being placed on buildings that are historic rather than just traditional.

    front-of-old-house

    An example of an historic building

    A Number of Areas of Performance are Considered

    These include looking at how the building copes with weather, climate, orientation, how the building is used, how much water vapour is produced, and identifying which areas are most at risk and under pressure.

     

    Understanding The Building is The Fundamental Principle to Making Alterations to a Period Property

    Without understanding the building it will not be possible to know how to respond to it. By learning about its performance and what may have significance culturally or otherwise, an informed plan can be made about how best to progress.

    Woolley Firs

    A derelict farm building at Woolley Firs

    It is Important to Make Sure You Have The Best Starting Point Before Making Alterations

    Richard believes that while people can have a pre-conceived idea of how they want the building to be, it is vital that to make sure that you understand the building and identify what works are required to put the building into good repair first, such as good rainwater management and a good roof.

    He thinks this process of learning and understanding can take a couple of years, before we can then know that the alterations will be compatible and beneficial to the building and not just fulfilling the pre-conceived idea.

     

    Some Existing Works May Need to be Undone to Improve The Building’s Performance

    A lot of Richard’s work involves undoing previous works that people have carried out that had the unintentional consequence of damaging the building. This is particularly the case where modern materials have been used in past repairs and which can cause long term damage and affect its intended performance. An example is that many modern insulation materials have impervious barriers which conflict with an older building’s need for moisture to be able to move in and out. This in turn changes how the building performs and can conceal problems of damp, mould and decay.

    Woolley Firs more thermally efficient roofThe detailing of the upgraded roof at Woolley Firs

    Opportunities Should be Seized to Improve Performance Without Having to Compromise

    Using diagnostic tools, such as air pressure tests, can help in determining problem areas. Richard believes that if the chance is there then the opportunity should be taken, for example, to improve thermal performance at a time when a roof is being stripped or an extension being built. These are therefore far more effective improvements, rather than if it had been attempted with the roof still on which will usually have to be a compromise.

    Wood fibre board is added

    The wood fibre board insulation at Woolley Firs

    Research Will Help Our Understanding of Buildings

    If an improvement is going to be made, it should be an effective improvement that is beneficial to the user and has real gains in terms of energy loss and reduction. Woolley Firs was an example of a building that had research carried out on how the different elevations were subject to warming, cooling and the elements. The results highlighted how the aspects performed differently.

    Using research and learning from mistakes will give a better scientific understanding to ensure that more informed decisions are made, and that improvements are better, more effective and do what is intended of them.

    The interior walls are plastered

    The interior is rendered with a lime plaster at Woolley Firs

    A Holistic View is Required to Understand How to Improve Performance

    Many questions need to be asked, such as: how was it constructed, is it in good condition, does anything need to be done, are there characteristics you want to maintain in future, what am I asking it to do, how has it been used, how is it being used and how is intended to be used? etc. The answers to these will help to identify where the problems are and dictate the improvements that are expected or the standard that is trying to be achieved.

    Richard notes however that it’s important to be wary of imposing modern, arbitrary standards on older buildings which can lead to conflict.

     

    Diagnostic Tools Will Identify Where to Concentrate Resources

    Richard gives an example of a National Trust property where use of air pressure testing found that 30% of heat loss was through the roof. Whilst there was some energy loss through other areas they were able to make the biggest impact by concentrating resources on repairing, insulating and re-cladding the roof, to maximise the performance of the building.

    A blower door test being carried out

     

    Get to Know Your Building Before Making Big Alterations!

    Richard emphasises how fundamental it is to understand your building first: how it was constructed, the materials that were used, are there conflicts in the performance, what works are required to get it to a good state in the first instance, how you intend to use the building, etc. This will ensure that resources are directed correctly and most effectively.

    Woolley-Firs-retrofit-finishedThe completed retrofit of Woolley Firs

    Find Out More

    Visit Oxley Conservation’s website

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    Follow Richard Oxley on Twitter

     

    Transcript

    Download a transcript of the interview with Richard Oxley.

     

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  • HPH017 : Can a Ground Source Heat Pump Make an Old House Energy Efficient? – with Justin Broadbent from isoenergy

    HPH017 : Can a Ground Source Heat Pump Make an Old House Energy Efficient? – with Justin Broadbent from isoenergy

    Justin Broadbent from isoenergy explains what a ground source heat pump is and how it could be used as a solution to make a period property energy efficient.

    Justin Broadbent

     

    Interview with Justin Broadbent

    Justin founded isoenergy 14 years ago after he sold his software company. An engineer by trade, Justin was keen to reduce the running costs of his period home and also get rid of his dependency on oil. As his father-in-law was a part owner in a Swedish manufacturer of heating systems, he began to discover more about Sweden’s approach to low energy buildings with very high levels of insulation and soon realised that the UK had a lot to learn about energy efficiency.

     

    Before Plugging in Something Mechanical, Reduce Your Heat Losses

    Justin started out as a consultant and as things grew he begun to import the machinery, too. This soon led to doing the installations as well. Even though isoenergy designs and installs renewable energy systems, a fabric first approach is always the starting point. The most expensive heat that you put into your house is the heat you’re putting in the second, third or fourth time, and so on, because you’ve lost it the first time.

     

    A Heat Pump Compresses Energy

    Justin explains how a heat pump works, using a bicycle pump as an example. As you inflate the tyre you may notice the end of the pump starts to get warm. This is because, as you compress the gas from the ambient air pressure (1 bar) through to the pressure you’re putting into the tyre (say 5 bar), the molecules get excited and so they get warm. Thus while the bicycle pump is running, it is a heat pump.

     

    Fridges are Heat Pumps

    A fridge takes the ambient air pressure out of the kitchen, which is perhaps at 18 or 20 degrees, compresses that heat and radiates it out at the back of the fridge. That is why the back of a fridge feels warm, normally at about 40 degrees. In engineering there’s always an equal and opposite to everything, so as heat is generated, so is cold. With a fridge freezer, the cold is kept but the heat is thrown away. In this case that doesn’t matter because you probably want to heat the kitchen anyway. A ground source heat pump works in the same way, using the heat for heating the house and putting the cold back into the ground.

    Refrigerator

     

    A Heat Pump Can Reduce Running Costs by up to Two Thirds

    In Justin’s experience most people become interested in reducing their energy usage because of the cost. He has had clients with heating bills of up to £80,000 a year and typically they can reduce running costs by two thirds.

     

    Even in a Period Property You Can Improve The Fabric of a Building

    Insulating the loft is often a very good starting point and sometimes insulating the cellar is an option, too. Most Grade I listed buildings nowadays have shutters built in, which are extremely good insulators when used. Stopping draughts can make a big difference.

     

    Use Old Buildings as They Were Originally Designed

    If you’re in a big house, there may be part of the house that can be sealed off when not in use. Use the fireplaces. Some chimneys draw very well and don’t create any draughts in the house.

    18th-century-house

     

    Secondary Glazing is Effective and Barely Noticed

    Justin has leaded light windows with wooden frames, but in front of the old oak frames there is a single pane of glass with a very thin oak frame going round it. In this case it is the size of the whole window area, but most people don’t even realise it is there, because you think you’re looking at the original windows. This not only drastically reduces heat loss but also acts as a sound buffer.

     

    The Cavity Wall is Left Uninsulated

    Even though Justin’s property has a cavity wall, he refuses to insulate it. This is because he has an oak-framed house with beams that have stood for hundreds of years. If any damp bridging occurs the wood could rot within in a decade. So Justin chooses to use an extra 20% on heating his house so that he knows that the walls remain secure.

     

    The House Stays at a Constant Temperature with Weather Compensation

    The difference between this and traditional heating systems is that a stable temperature, in this case 20 degrees, is maintained all year round. That means that the walls are also at 20 degrees. Even if the outside temperature is -6, the inside walls stay at 20 degrees and actually act as a radiator. This therefore takes advantage of the thermal mass, which is a good quality. Around the time when the house was built, it would have been run in the same way. A fire would have been kept going throughout the day and temperatures would be fairly constant, even if significantly colder than how we live today (perhaps 15 or 16 degrees).

     

    The Radiators Never Get Above 50 Degrees

    Many people say that you need to oversize the radiators when using a ground source heat pump, but Justin is using the same radiators that were heating his house when it ran on oil. The difference is that with oil, you tend to switch the heating on and off, especially if you think you’re saving money. What Justin does is put in a lower grade of temperature but for a 24-hour period. So it’s all about maintaining the temperature. Rather than the radiators getting up to 70 or 80 degrees, his radiators probably never go above 45 or 50 degrees.

     

    Heat Pumps Are Reliable

    Justin explains that more could go wrong with a boiler than it can with a heat pump. When it’s done properly it should be just as reliable as a fridge and most people replace their fridges when the door handle falls off or the seal breaks rather than when the compressor malfunctions.

    Plant-room-equipment

     

    Problems Arise if You Don’t Understand Where The Energy Comes From

    Some people perceive ground source heat pumps as magic, but there is an engineering reason why it works. You are taking a small amount of heat from a large area. For example if you tried to take half a million kilowatt hours out of a piece of land the size of a tennis court, it will turn into a block of ice. So you would need to take that half a million kilowatt hours out of a 5, 10, 15 or 20-acre field. The larger the better. The more the load is spread, the more efficient the system will be.

     

    The Ground Must be Taken Into Account

    There are many factors that must be understood before a system can be designed. For example, it matters how much water is in the ground, how much of a slope there is, what substance the ground is (e.g. clay, sand, shale, etc.). Different substances have different heating properties and different heat transfer ratios. So, it’s important to understand what they are and do the calculations properly. Equally it’s vital to make sure that the turbulence in the pipe is right so that you can extract the heat properly and that the flow pressures are right. Justin says it’s all about understanding pressure losses, heat curves and algorithms.

    Ground-Loops-12 Ground loops being laid

    Hydro Systems Can Payback Quickly

    Justin suggests that you need to consider the renewable technology that will work for your particular situation, whatever that might be. For example, if there’s a stream with a good flow and a good drop in it, then a hydro system could have potential. The payback can be very quick.

    Archimedes-Screw-going-in

     

    Be Aware of Government Grants

    In the UK, the government is bringing out the Renewable Heat Incentive. This will pay people to replace their oil fired boilers with heat pumps and biomass boilers to heat their houses. Those grants are looking like they’re going to be particularly generous. There is, of course, an upfront cost of installing the equipment.

     

    Find Out More About isoenergy

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    Follow isoenergy on Twitter

    Download a PDF of case studies

     

    Transcript

    Download a transcript of the interview with Justin Broadbent.

     

    Ask Your Questions or Share Your Feedback

     

    Home Style Green Podcast

    If you enjoy listening to the House Planning Help Podcast, then Ben recommends that you check out Home Style Green. Matthew Cutler-Welsh is based in New Zealand and is involved in green building there. He shares some invaluable information.

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  • Google+ Hangout – The Balance Between Heritage and Sustainable Design

    At the start of the year we mentioned that we wanted to host some Google+ Hangouts to debate issues that are not so clear cut.

    We are pleased to announce that our first forum will be on Monday 18th February 2013 at 8.30pm.

    google-plus

    A panel of experts and home owners will get in front of their webcams for the debate and the programme will be transmitted live on YouTube. A pre-recorded version will also be available to review after the event.

    Our subject for this first session is:

    The Balance Between Heritage and Sustainable Design

    What’s more important – preserving heritage architecture or retrofitting it to high energy efficiency? There has to be a balance between the past and the future, particularly if we accept that we have to reduce our fossil fuel dependency. Where is that line?

    Our panel consists:

    Writer and blogger Roger Hunt (who appeared in our 10th podcast)

    Writer and Passivhaus consultant Adam Dadeby from Passivhaus Homes (who appeared in our 5th podcast)

    Homeowner Ross Atkin (who has recently retrofitted his Victorian house)

     

    Ben Adam-Smith will be leading the discussion and it is scheduled to be 30 minutes long.

    The programme will be available on our YouTube Channel.

     

    Would you like to get your voice heard on this topic? Either get interactive as the broadcast goes out or send an email with your thoughts in advance.