Energy Retrofitting of Existing Houses

Energy Retrofitting to Houses

Part one of a two part blog on retrofitting of existing houses

Today there is a huge industry insulating existing houses with claims that wall insulation, roof insulation will reduce your heat loss and reduce your heating bills

Cavity wall insulation, loft insulation, and external wall insulation all harbour good tidings.

Government grants have been trumpeted as a way of offsetting costs and with it reducing energy and carbon footprint.

In the midst of all the hoopla surrounding the benefits of insulation retrofitting, the elephant in the room has not been answered and in some cases not yet seen.

Is insulation retrofitting really reducing the energy costs of existing houses or is it a giant mistake.

As with any juggernaut the danger is that when it gathers speed and especially a government backed juggernaut it is hard or impossible to stop.

Let’s look at each type of insulation system.

Cavity fill

The rationale of filling the cavity with insulation appears to be sound but it doesn’t offer any solutions to cold bridging within the cavity from floors, windows or the roof.

Thus the wall fabric which in many cases has the most basic type of insulation probably badly fitted is now treated with an insulation that may or may not fill the cavity (there is no way of knowing).

Even if we concede that the cavity is fully filled what real improvement to the wall U value has occurred.

Applying the U value calculations may show a marginal improvement in the overall wall U value but as it doesn’t affect the cold bridging issues it has actually exacerbated the problem as perversely increasing fabrics U value will increase the heat transfer at cold bridging locations.

This also results in lower temperatures at cold bridge locations causing condensation problems.

I am not saying that cavity fill is useless but without proper analysis its effectiveness in reducing fabric heat loss is suspect.

External wall insulation

Again the rationale of using external insulation looks sound but on examination it also has more questions than it answers.

Wall insulation usually starts at DPC level which is between 150mm to 200m above ground level and stops at roof soffit level.

The insulation that is used is relatively poor thus the U value is not greatly enhanced but this is the least of the problems facing external insulation.

The fact that the upper and lower parts of the wall fabric are un-insulated means that the insulation is either entirely useless or greatly diminished.

Again with the exception of joists at 1^st floor no system reduces or eliminates cold bridging.

I suspect little or no technical data exists in determining before or after heat losses of external wall insulation systems.

The claims of a large drop in wall U values are simply not true.

Attic Insulation

This is perhaps the only type of insulation that makes any sense.

And unfortunately it also suffers from the dreaded cold bridge problems at the roof perimeter.

But in saying that the relative cost in insulating the attic is small and some reduction of heat loss is possible.

Conclusion

The problems with arguing against the merits of insulation is not that the insulations don’t work but that they cannot be expected to work in a retrofit situation without addressing the other basic problems of cold bridging and air tightness.

That hasn’t stopped insulation companies selling insulation by the truck load but to what use.

The government’s logic is that insulation is good so why not induce the public to buy it with grants.

That most of the systems are untried in recording heat loss reductions and cannot scientifically say what heat loss reduction has occurred leads me to suspect that none of them actually work or work anything like as effective as claimed.

The second part of this blog is concerned with effective ways to reduce heat loss without using insulation.

Performance Gap in House Construction

Performance Gap

Performance gap is the difference between the theoretical performance and the actual performance of houses in terms of energy consumption.

Performance gaps are all around us every day and we are normally not aware of the gap mainly as the difference in performance is minimal.

However it is noticeable in certain products or services.

Broadband

Take for example broadband service where you buy a deliverable broadband speed say of 100MB but record on your PC a speed of 25MB.

If you complain to your provider they will tell you that the speed will vary according to usage and that they are allowed up to, in some cases 80% differential, from that sold to the customer.

Thus you might get near what you paid for at 4 am on a Sunday morning.

The same can be said for most products that give values under laboratory conditions where the working values are often 25% to 30% below the given values.

Houses

The problem for house construction is that the BER (Building Energy Rating) is a statement not only of compliance but also a statement of fact.

Thus your BER (Building Energy Rating)  may say that your house is an A1 house but you have no way of knowing if its performance is as per the BER (Building Energy Rating) .

In the UK it has been found that the performance gap is at times five times worse than that designed for.

So in theory your A rated house may be a D or E rated house.

The lack of creditable data on the actual energy output is both disappointing to the owner but also places the credibility of energy efficiency in doubt.

The way forward is in reliable measurements so the owner or occupier has faith in the energy rating that they are given is in fact correct.

Reliable measurements in house construction come in the form of air tightness which is measurable and solar gain which though a variable is reliable over the long term.

Fabric U values

What needs to be addressed are the fabric heat losses.

It is easy to give a wall a U value but how is that wall actually performing against the theoretical value.

The complexity of the interaction of walls to floors, windows and ceilings as well as the construction of the wall itself all diminish the performance in terms of U value.

Of course at the heart of all this is the workmanship in the construction phase as well as the robustness of the design.

Ventilation

Other elements such as ventilation systems claim up to 95% efficiency.

This when put into  software calculating the energy rating gives super results but are we deluding ourselves in using these figures.

Poorly constructed ducting can dramatically reduce the performance of the system and if filters are not cleaned then the system is also affected.

Window U values are now falling to meet  energy efficiency requirements but what of the long term effects of gas loss in windows on their U values.

The performance gap in house construction is serious because of the quantity of houses and the increased energy requirement if it isn’t closed.

Closing the gap is of great interest to the buyer and occupier as it gives certainty of energy use.

 

Simple Tips to Kitchen Layouts

Simple Tips on Kitchen Layout

The Kitchen is the social center of any house.

It is the focal point of the house and family.

Whether it’s just a snack or preparing a big meal the area is used for conversation as well as a working environment.

Because it is the most important social area of the house it needs to be designed to cater for socializing as well as working at the same time.

Here are a few tips in how to optimize your space.

The kitchen triangle.

Make sure that you have unobstructed access to the sink the oven and the fridge.

The sink is central to the kitchen and moving from it to both the oven and fridge is essential to having a well designed work area.

Don’t get confused by appliances and their locations.

The most important element in a kitchen is you and having obstructed routes will ruin the functionality of the kitchen.

The space between the sink, oven and fridge should be around ten feet. Anything more will be too long and anything less will result in people tripping over each other.

Don’t ignore counter-top work space.

Counters are where most of the work is done in a kitchen so having it carefully designed is a must. Place appliance in corners so space is not wasted.

The width of counters should be thought through. Having to work under units is not ideal so additional counter width even a few inches can make all the difference.

If you are lucky to be able to have an island, don’t clutter it with a great big sink. In a kitchen working space is everything.

Don’t waste storage space.

Plan your kitchen with how you are going to store stuff. Having a plan on what you need and how you would like to store it is essential.

Don’t let appliance get in your way. Too often kitchens are packed with appliances and not enough storage. Having the dishwasher in the utility saves and creates storage space in smaller kitchens. List out the types of stuff you need in your kitchen and how it should be stored.

Having small appliances used infrequently in prime storage locations doesn’t make sense.

The most used goods should be stored closest to hand.

Look at optimizing your space by adding dividers to units.

Think outside the box like utilizing the space above large refrigerators with say a wine rack.

Hygiene, Hygiene, Hygiene

Your kitchen is the one area where you need to be hygienic.

The choices you make in the kitchen type and materials go a long way to achieving a spotless kitchen.

The idea of a rustic kitchen doesn’t mean you should sacrifice cleanliness.

A hand painted kitchen may look great but if it harbors germs or is a nightmare to clean then it should be a non runner.

The same should be true of tiles. Soft tiles that require sealing are a definite no no in kitchens. Don’t let your heart rule your head in picking materials for your kitchen.

Surfaces that  are wipe clean will save you time and help maintain your kitchen as a germ free area.

Finally design out corners and crevices that will harbor dirt and grime.

 

Poor Lighting.

Lighting is often overlooked but good lighting adds to the atmosphere and helps in making the working area more usable.

The lighting should be divided into mood lighting and practical lighting.

Mood lighting can be under counter ceiling or wall lighting but don’t overdo it. Clever mood lighting shows off the beauty of your kitchen when it is cleaned and at rest.

Practical lighting is to ensure you get enough light where you are preparing food.

Direct lighting to your work area is important. Overall lux levels should be high can be dimmer controlled.

Ventilation

Kitchen ventilation not only improves the air quality and live ability of your kitchen but will greatly reduce cleaning and improve hygiene.

The golden rule of ventilation is to get a big enough fan.

Fancy ventilation systems above cookers that have everything except power to extract the air are a disaster.

The other thing is, that extract fans need to be cleaned and filters replaced.

If possible get a filter that can be cleaned in the dishwasher.

The replaceable systems mean a conscious effort to replace the filter and that only occurs when the fan starts to perform poorly.

Latest Fashion

Kitchens are expensive so think carefully before buying a kitchen with crazy colours.

Think in the long term.

There was a craze in the eighties for pink sanitary ware but it quickly faded leaving people with weird bathrooms.

The same with kitchens as you will use it for at least ten years.

If that’s your style fine, but again if you need to sell your house it may be a real turn off.

Think carefully before deciding.

Simple tips in setting out power and data points

Simple Tips in setting out electrics and Data points in a new house

The positioning of everything in a new house is important.

In particular positioning of sockets and data points is very important

You only have one chance to do it right so remember the old saying

It’s better to be looking at it than for it.

Bedrooms

Bedrooms need phone points and tv points and internet points.

The use of internet points in bedrooms is often forgotten and if you are depending on wireless then you will be disappointed.

Make sure you are wired back to your router for all bedrooms.

Despite the virtues of wireless a direct connect gives perfect results every time.

The way a bedroom is set out depends on the wardrobe not the bed and everything flows from its position.

Remember to put your internet connection near your bed to get the most out of your handheld gadgets. If you can afford it wire the lighting with a switch near the bed.

Finally put at least one double socket either side of the bed.

Kitchen/Utility

The kitchen sets out what you need in this area.

Be careful about the sink and oven positions when positioning the sockets.

If you are looking for under press lighting leave switches in place.

Allow for one additional socket under counter. It is always used.

Again position data points properly. Most appliances are now internet ready so a data point from the router is essential.

Of course a TV point in the kitchen should be thought out so it can be seen from the cooking area.

Finally remember fixed points for fans,ovens etc are required and should be talked through with the electrician.

Living Room

The room should be set out with the sofa and TV.

Most TV’s are central to the room so it is important to think through what will be required in terms of sockets data points and TV

It is best to cater for systems such as SKY which require a socket, a phone point and an internet point. In particular if you have a smart TV a hardwired connection to your router is essential.

Add TV power, surround sound, DVD you quickly get a lot of sockets.

It may be wise to have four power sockets with a tower socket as the system builds up.

That’s just the TV area!

Lamp lighting is popular in living room areas and sockets should really be at every corner.

And don’t forget the Christmas tree.

The Router

The router takes on added significance with all our lives dominated by the internet.

Putting direct wiring from the router is vital in future proofing your house.

If your house is very big with concrete walls have a direct wire to the attic where additional routers can be added.

If you are spending additional money put it into the router and access to your house. It will pay off over time.

Externals

Power to the outside is very important long term.

Put isolated boxes in the garden even if you are years of cultivating it properly.

Make sure you map the runs so you won’t electrocute yourself later.

Wire to the venerable points on your house for camera and lighting.

 

Smoke and Carbon monoxide detectors

Get the minimum standard and add extras.

It could save your life.

Security

Oddly the use of wired systems are now becoming obsolete because the internet connects us so quickly. However if the internet fails or is cut then an internet system fails.

A combination of both would seem the prudent way to go.

 

 

 

 

Rain Water Harvesting

Rainwater Harvesting

New houses will be required to install a rainwater harvesting system by 2015 and most local authorities are conditioning it with planning permissions.

At the onset the cost of rainwater harvesting is expensive and the return on the investment will take about twenty years based on a 50% reduction in mains water consumption.

Note that the offsetting of water is far more beneficial to water authorities than to the home owner.

We use about the following amounts of water in our daily usage.

water pie chart

49% of the water we use can be non potable or drinkable.

There are a myriad of excellent systems all of which will harvest rainwater.

They range from the basic to the technical

All are costly

When deciding on a type it is important to remember that the system no matter how many bells and whistles is just collecting water for use in non potable areas.

With that in mind the following system will easily suffice.

1. The water tank should be capable of resisting the weight of cars or small trucks if in the drive or if in the garden the weight of soil and lawnmower. It is wise to plan its position so it will not be subjected to constant loadings but also that it will not interfere with future plans. The type of tank can be either concrete or plastic.
2. The tank should have the mains water connected to the tank with a ball cock. This will ensure in times of drought the tank is kept filled. This allows a simpler system within the house.
3. The pump used for pumping rainwater into the house is kept in the tank to eliminate noise.
4. A separate tank should be installed in the attic for rainwater with no connection to other tanks. The ball cock arrangement will be the same as normal but with a float sensor to cut out the pump. Overflow pipes from the attic tank is standard. The tank should be clearly marked rainwater.
5. Pipe work from the attic rainwater tank should be clearly marked either by tags or preferably by painting the pipes.
6. The filtering of the water is important both for the pump and the system. Filtering in the down pipes is recommended and further filtering in the tank. The pump should be situated at the top of the water where it is most calm.
7. The underground tank will also have an over flow in times of heavy rains.
8. Outside taps should be lockable with clear signage not to drink.
9. Use water wisely e.g. power washing should be done on rainy days.

Filtering water to Potable levels

There are systems to bring rain water to potable levels but should not be recommended.

Such systems require careful maintenance and the dangers are obvious.

What solar should I use.

Building a new house requires a renewable energy source.

This source is measured typically in solar renewables.

If you opt for water heating then the requirement are solar panels with an energy requirement of 10KW/m2/annum

If you opt for photovoltaic solar panels the energy requirement is 4KW/m2/annum

The question is what is the best solution for you.

Solar Thermal is the most used system in Ireland and is tried and tested.

If you are thinking of installing solar water panels then flat panels give a slightly better reading on the DEAP software so helps the BER rating.

The advantages

solar thermal

• It is the best known solar technology in the country
• It heats water and sized properly it can reduce water heating by 60% to 70%
• It can be used for space heating

The disadvantages

• It is expensive
• It has a lot of moving parts
• It needs safety controls if water is not used in hot weather.
• It needs maintenance.

Photovoltaic is not as widely used in Ireland as costs, lack of grants and poor prices for exported electricity. It has however advantages over solar themal

Advantages of photovoltaic

solar photovoltaic

• No moving parts of maintenance over its lifetime.
• Performs very well in DEAP
• It can generate some money if power is exported to the grid
• It is clean and will offset your electricity bills

Disadvantages

• Expensive to install (but costs are falling)
• Very poor prices to export as against European neighbours
• Invertors can be problematic

In selecting a solar renewable energy source you need to consider the best solution in terms of economics and also in terms of how it affects your BER rating

Photovoltaic is much better in reducing your primary energy costs and your carbon emissions.

Both systems are designed to reduce your energy costs though it is debatable on the pay back of either technology so the use of either should be a combination of price allied to how it affects your BER rating which may influence your house sale in the future.

Passive House Revolution

The Passive revolution

House building is set to revolutionise by the onset of Passive Houses.

Passive houses answer nearly all the requirements in energy saving of new housing stock.

The upper limits of passive houses are quite onerous on developers and designers

The Upper limits are

Walls                                                                                     equal or less than 0.015W/m2K

Floors                                                                                    equal or less than 0.015W/m2K

Roofs                                                                                    equal or less than 0.015W/m2K

Glazing                                                                                  equal or less than 0.80W/m2K

Air-tightness                                                                      at n50 equal or less than 0.6n-1

Thermal Bridging                                                              linear coefficient of less than 0.01 W/(mk)

Heat recovery                                                                   equal or greater than 75%

Solar transmittance                                                         equal or greater than 50%

Air flow                                                                              30m3 per person per hour

 

The above figures are extraordinary hard to achieve without detailed design and excellent workmanship.

For home owners it is like driving a family car with a few bells and whistles to now driving a Rolls Royce for the same price.

If we can deliver houses to meet the above standards it will completely change the living habits for future generations of home owners.

Traditional heating systems will disappear. This will mean no open fires, no oil or gas boilers no heating systems or heating bills.

Is this just pie in the sky or is it the new reality.

Well the beautiful thing about Passive houses is that the upper limits described above are measurable and if achieved the house will function just like any other appliance you have.

Thinking of your house in the same way you think about your car or fridge may be difficult but the beauty of the passive house system is that the parts will not wear out if assembled properly at the start.

The way we use windows to get fresh air will cease as windows will now are used only for light and heat transmittance.

Opening windows will be in place but only as a safety device and all the fresh air will be supplied with a whole house heat exchanger.

The outside skin of houses will change in that they will become thicker simply to accommodate the increased volumes of insulation required.

One of the by products of passive construction is noise reduction in the house due to increased insulation and improved air tightness.

Passive house demand that appliances are A rated and energy efficient lighting is the norm which are subject to owner discretion.

Temperature variation is something passive houses eliminate and a mean temperature of about 21c is normal throughout the year.

This temperature is made up of heat gains from a variety of sources such as solar parasitic heat gains from appliances and human and animal heat.

All the above heat gains are recycled through the energy recovery ventilation system.

If the mean temperature falls the difference is made up by heating the incoming air or by a small heating device within the house such as a stove.

The reduction or elimination of traditional heating systems will compensate for the additional cost of insulation and windows.

All in all the Passive revolution is now starting to gain traction

Whole house automation

What is Home Automation.

One of the great things about the internet is its ability to control remotely.

When this is applied to houses it opens up a whole range of elements that can be controlled remotely.

Home automation gives you remote and automatic control of a wide array of devices in your home. Home automation can also alert you to events that you might want to know about right-away while you are gone such as   water leaks and unexpected access to your home, or any part of it.

At any time, you can grab your phone or other remote control devices and change the settings in your house as desired. For automation, you dictate how a device should react,

Whole house automation controller

when it should react, and why it should react. You set the schedule and the rest is automated and based off of your personal preferences thus providing convenience, control, money savings, and an overall smarter home.

The scope and control of what you can achieve is only limited to your control system and your imagination.

From controlling temperatures in your house to the audio systems to security to having the bathroom heat up before you take a shower are just some of the things a whole house automation system can do.

That smart home products can be programmed to save energy only adds to the benefits of the system.

Here are some of the areas that are controllable.

Lighting

With ever increasing energy costs; automation controllers are often used to manage your lights. Using control systems with lighting saves money and gives you complete control including developing mood lighting, dimming and lighting control by motion detectors.

 

Safety

Perhaps the best feature of home automation is the way it can be adopted to security in your home.

Setting up a lighting schedule while the house is unoccupied to lighting up if motion detectors are tripped.

Home automation can allow you to see your home in real time while you are away to instant communication to you and key holders if an event takes place.

 

 

Audio/Video

With whole house automation you can have your whole house rock to your favourite tunes.

You can watch programmes in multiple rooms or switch channel by voice control.

You can make your house the system suit whatever mood you are in to party time or relaxing time.

Appliances

With whole house automation you can use your appliances remotely.

From washing machines to dish washers the technology allows you to start machines at times suitable to you and when energy costs are lowest.

 

Overall whole house automation makes your home smarter and more economical.

It allows for greater interaction with your home security and other systems to suit your needs.

With whole house systems you are in control.

 

Self building now a dangerous game.

Building control Act 2014

The Building control act is now law and as such all the arguments about it are mute. ( for the moment)

In many ways the act was a necessary evil in that it for the first time crystallized a set of standards that were badly needed in the industry.

We now have a situation where a house is built by a builder or self builder and signed off by a professional.

The act looks for

• A  Commencment Notice
• General arrangement drawings;
• A schedule of design documents as are currently prepared or to be prepared;
• The preliminary inspection plan;
• A Certificate of Compliance (Design);
• Notices of Assignment in respect of the Builder who will carry out the  works and of the Assigned Certifier who will inspect and certify the works;
• Certificates of Compliance signed by the Builder and the Assigned Certifier undertaking to carry-out their roles in accordance with the Requirements of the Building Regulations.

This is vast improvement of what was a wild west show type building enviroment where developers after planning permissions were approved, effectively disgarded the Architects and build out developments without any oversight.

The only interaction with the Architects were alterations to planning permissions and final sign off which was so heavily loaded with opt outs it was completely dependent on the builder /developer building correctly.

This act is intended to cover all private and public sector construction but its main focus is on private residential developments either large or small.

The problem for one time, house, self builders is that the act has a hugely negative effect on them.

Though they are probably the most compliant and competent in achieving or exceeding building standards they are now an endangered species.

The act places an onus on the self builder to certify that they are competent in building the house to meet the building regulations.

This is a real problem for a person undertaking a house build.

Even persons working within the construction industry or with a working knowledge of the industry would be foolhardy to venture into building a house as a certified builder.

It will also pose extraordinary problems for architects and engineers to co sign documents with a self builder.

The issue for professionals is competence and compliance. Is a self builder competent and what happens if a defect arises.

Is the professional liable for defects on works carried out by a self builder whose competence is questionable.

For the self builder the danger lies in many areas not least the possibility of problems in relation to finance and certification requirements of financial institutions with respect to certification.

If a self builder sells the house in the future will the buyer need certifcation of a registrar ed builder rather than a self builder.

All in all the days of self building are over and the act though crude in many ways can only improve the standard of work.

 

 

 

 

 

Renewable Energy For houses

Renewable Energy Requirements

Water Solar Heating

The building regulations call as a minimum requirement of 10 kWh/m2/annum of renewable energy for hot water.

A typical well sized solar thermal system should provide around 50-70% of the domestic hot water requirements of the home, representing a worthwhile saving on hot water heating costs.

The remaining hot water requirement is provided by the boiler.

A common question about solar water heating is whether there’s enough sunshine available to make solar worthwhile.

Contrary to popular belief the amount of solar radiation received in this area is enough for solar water heating to be a viable supplement to existing domestic water heating.

The map on the right shows typical annual solar radiation falling within a square metre of

Solar Radiation Map of Ireland

ground in the Ireland.

Perhaps surprisingly, Ireland in particular receives 65% of the amount of solar radiation that is received by the south of Spain.

The radiation in Ireland is made up of direct radiation on sunny days, which accounts for around 40%, and diffused radiation on cloudy days, accounting for 60% of the total.

Solar water heating panels have been developed with this typical weather in mind and make the most of both direct and diffused sunlight to give a useful annual contribution wherever you are in Ireland.

Summer will provide the largest amount of solar radiation over the year but a useful contribution will also be provided by other seasons.

As an indication, a well sized typical solar water heating installation will provide the

Solar water Heating

following proportion of the household’s domestic hot water requirement:

Solar energy provides on a well sized and installed sytem

Summer up to                                      85%

Spring and  Autumn                            45%

Winter                                                    20%

Photovoltaic Solar Panels

For renewable energy generating electricity a  4 kWh/m2/annum is required.

This method of renewable energy is in many ways better as it cuts down on the amount of

Photovoltaic solar panels

electricity being generated.

It is leaner in that it generates electricity which can be used in the home.

It is expensive relative to solar water heating.

It has a big drawback as the payments for any power going back to the grid is too small standards and as such is not used extensively.